Contents
General introduction xii
1 Glasses and glass-ceramics 1
1 Glasses . . . 1
1.1 Definition [9, 10, 11] . . . 1
1.2 Glass transition . . . 2
2 Glass formation . . . 4
2.1 Structural theories of glass formation [10, 11, 16] . . . 5
2.2 Kinetic theory [11, 13] . . . 13
3 Glass-ceramics [25, 32] . . . 16
2 Phase transformations in glasses 20 1 Introduction . . . 20
2 Crystallization . . . 21
2.1 Nucleation: Classical Theory for Nucleation (CTN) . . . 22
2.1.1 Homogeneous nucleation [37, 36] . . . 22
2.1.2 Heterogeneous nucleation . . . 25
2.2 Growth [36, 39] . . . 27
3 Volume nucleation versus surface nucleation in silicate glasses . . . 30
4 Amorphous Phase Separation (APS) . . . 31
4.1 Thermodynamic considerations . . . 33
4.2 Phase separation mechanisms and morphology . . . 35
4.3 Kinetic of phase separation . . . 37
5 Effect of amorphous phase separation on subsequent crystallization . . . 38
5.1 Phase separation as a precursor reaction [55, 59] . . . 39
5.2 Shift in composition . . . 40
5.3 The creation of interfaces . . . 42
5.4 "Mechanical" interferences . . . 42
6 Use of phase separation in glass-ceramics . . . 42
3 BaO-TiO2-SiO2 system 45
2 Fresnoite Ba2TiSi2O8 . . . 50
4 CALPHAD 54 1 Motivations and objectives . . . 54
2 What is CALPHAD? . . . 55
2.1 Gibbs energy and phase stability . . . 56
2.2 Phase diagram calculation . . . 58
3 CALPHAD method . . . 60
3.1 Thermodynamic model selection [108, 112, 116] . . . 61
3.2 Software selection [108] . . . 62
3.3 Collection and assessment of literature data [108, 112, 115, 116] . . . 62
3.4 Parameters optimization [108, 112, 115, 116] . . . 63
4 Description of the Gibbs free energy . . . 64
4.1 Solution phase: theory of solution [111] . . . 65
4.1.1 Raoultian ideal solutions . . . 65
4.1.2 Non-ideal solutions models . . . 66
i Deviations from ideality . . . 66
ii Regular Solution . . . 67
iii Subregular solutions and higher orders . . . 68
4.1.3 Other solution models for liquid oxides [108] . . . 70
4.2 Terminal phases or "end-members" . . . 71
4.3 Stoichiometric compounds or intermetallics . . . 71
4.4 Intermediate compounds with solubility . . . 71
5 Extrapolation of the Gibbs excess energy to multi-components systems [109, 112, 121, 122] . . . 71
6 Ionic Two sublattice (I2SL) model and formalism [109, 112, 123] . . . 73
5 Review of literature data for the thermodynamic assessments 77 1 BaO-TiO2 system . . . 77
2 SiO2-TiO2 system . . . 79
3 BaO-SiO2 system . . . 81
4 BaO-SiO2-TiO2 system . . . 84
6 Material and experimental procedures 85 1 Material . . . 85
1.1 Glass synthesis . . . 85
1.2 Glass compositions . . . 85
1.3 Glass sample preparation . . . 86
2 Heat treatments . . . 86
3 Glass characterization . . . 87
3.1 Composition measurement . . . 87
3.1.1 X-Ray fluorescence (XRF) . . . 87
3.1.2 Energy dispersive X-ray (EDX) . . . 87
3.1.3 Spatially resolved electron energy loss spectroscopy (EELS) . . 88
3.2 Differential thermal analysis (DTA) . . . 88
4 Microstructure characterization . . . 90
5 Crystallization characterization . . . 90
5.1 X-Ray diffraction (XRD) . . . 90
5.2 Electron backscatter diffraction (EBSD) [168, 169, 170] . . . 91
5.3 ACOM-TEM/ASTAR . . . 92
6 Photoluminescence measurements . . . 93
7 Critical assessments and thermodynamic modeling of BaO-SiO2 and SiO2-TiO2 sys- tems and their extensions into the liquid immiscibility in the BaO-SiO2-TiO2 system 94 1 Introduction . . . 94
2 Experiment . . . 95
2.1 Material . . . 95
2.2 Glass characterization . . . 97
2.3 Phase separation characterization . . . 97
2.3.1 Phase separation boundary . . . 98
2.3.2 Composition measurements . . . 98
3 The Ionic Two Sublattice formalism . . . 98
3.1 BaO-TiO2 system . . . 99
3.2 SiO2-TiO2 system . . . 99
3.2.1 Liquid phase . . . 99
3.2.2 Terminal phases . . . 100
3.2.3 Solid phase . . . 100
3.3 BaO-SiO2 . . . 101
3.3.1 Liquid phase . . . 101
3.3.2 Terminal phases . . . 102
3.3.3 Solid phases . . . 102
3.4 BaO-SiO2-TiO2 system . . . 103
3.4.1 Liquid phase . . . 103
4 Thermo-Calc . . . 105
5 Optimization . . . 106
6 Results . . . 106
6.1 SiO2-TiO2 system . . . 106
6.2 BaO-SiO . . . 109
7 Discussion . . . 120
7.1 SiO2-TiO2 system . . . 120
7.2 BaO-SiO2 system . . . 121
7.3 BaO-SiO2-TiO2 system . . . 122
7.4 Limitations . . . 123
8 Conclusions . . . 124
8 Influence of amorphous phase separation on the crystallization behaviour of fresnoite125 1 Introduction . . . 125
2 Experiment . . . 126
2.1 Material . . . 126
2.2 Glass characterization . . . 127
2.3 Systematic study of the crystallization . . . 127
3 Results . . . 128
3.1 Glass characterization . . . 128
3.2 Avrami parameters and activation energy for crystallization as ways to de- termine the crystallization mechanism . . . 129
3.3 Microstructure evolution . . . 133
3.4 Crystallographic orientation: XRD, EBSD and ACOM-TEM . . . 135
3.5 HAADF-STEM . . . 142
4 Discussion . . . 143
4.1 Crystallization mechanisms determined by DTA . . . 143
4.2 Microstructure . . . 144
4.3 Comparison with literature . . . 146
5 Conclusions . . . 147
9 Influence of composition on microstructure development after direct annealing 148 1 Introduction . . . 148
2 Experiment . . . 149
2.1 Material . . . 149
2.2 Glass characterization . . . 149
2.3 Study of the crystallization . . . 150
3 Results . . . 151
3.1 Glass characterization . . . 151
3.2 Microstructure characterization . . . 152
3.2.1 T=900°C (T>Tx) . . . 152
3.2.2 T=1000°C . . . 153
3.2.3 T=1100°C . . . 162
3.2.4 T=1200°C . . . 168
3.2.5 T=1300°C (T>Teutectic) . . . 171
4 Discussion . . . 172
4.1 Influence of composition . . . 172
4.2 Influence of annealing temperature . . . 174
4.3 Influence of annealing time . . . 175
5 Conclusions . . . 175
10 Prior heat treatment before annealing and its effect on microstructure development177 1 Introduction . . . 177
2 Experiment . . . 177
2.1 Material . . . 177
2.2 Glass characterization . . . 178
2.3 Study of the crystallization . . . 178
3 Results . . . 179
3.1 Heat treatments and subsequent isothermal step at 1000°C . . . 179
3.1.1 Hypo-eutectic compositions . . . 179
3.1.2 Hyper-eutectic compositions . . . 182
3.2 Heat treatments and subsequent isothermal step at 1200°C . . . 188
4 Discussion . . . 193
5 Conclusions . . . 194
11 Summary of phases formation along the Ba2TiSi2O8-SiO2 line 196 1 Introduction . . . 196
2 Amorphous SiO2-rich droplets . . . 196
3 Ti-depleted needles . . . 197
4 Fresnoite . . . 198
5 Cristobalite . . . 200
6 Link between the microstructure and the process parameters . . . 203
12 Effect of composition and process parameters on the photoluminescence of fresnoite207 1 Introduction . . . 207
2 Experiment . . . 208
2.1 Material . . . 208
2.2 Study of the crystallization . . . 208
2.3 Photoluminescence . . . 208
3 Results . . . 208
4 Discussion . . . 212
5 Conclusions . . . 213
13 Extension to the soda-lime-silica system (Na2O-CaO-SiO2) 214
1 Introduction . . . 214
2 Phase diagrams . . . 216
3 Experiment . . . 218
3.1 Material . . . 218
3.2 Glass characterization . . . 219
3.3 Crystallization study . . . 219
3.4 Addition of oxides . . . 220
4 Results . . . 222
4.1 Glass characterization . . . 222
4.2 Improvment of mechanical properties of Ter . . . 223
4.3 Crystallization behavior for two reference compositions . . . 224
4.3.1 Bin . . . 224
4.3.2 Ter . . . 228
4.4 Change of the binodal temperature: Ter-LowSiO2 and Ter-highSiO2 . . . 232
4.5 Proximity of a crystal phase stabilizing phase separation: Ter-CaO-1 and Ter-CaO-2 . . . 236
4.6 Oxide additions . . . 239
4.7 Phase separation morphology . . . 241
5 Discussion . . . 243
5.1 Crystallization behavior of two reference compositions . . . 243
5.2 Change of binodal temperature . . . 245
5.3 Proximity of a crystal phase stabilizing phase separation . . . 245
5.4 Addition of oxides . . . 247
5.5 Phase separation morphology . . . 247
6 Conclusions . . . 247
14 Discussion: interplay between phase separation and crystallization 250 15 Conclusions and prospects 255 A Volume versus surface crystallization in silicate glasses 279 B The Origin of thermodynamic non-ideality [47, 222, 223] 285 C The interplay between amorphous phase separation on crystallization: a subject of debate 291 D Fresnoite (Ba2TiSi2O8) properties 304 1 Piezoelectricity, pyroelectricity . . . 304
2 Optical non-linearity . . . 305
3 Blue-white luminescence . . . 307
E Solution models for ionic liquids 309 1 The cellular model [109, 108] . . . 309
2 The Modified Quasi-Chemical model [109, 108] . . . 309
3 The Ionic Two Sublattices model [109, 123, 108] . . . 309
4 The Associate model [109, 108] . . . 310
5 Other models [108] . . . 310
F Glass synthesis 311
G Ba-Si-Ti-O database 313
List of Figures
1 (a) Tensile strength and fracture toughness in soda-lime glasses and (b) a glass-
ceramic - CES 2010 . . . xiii
2 (a) house cooking , (b) zirconia knifes , and (c) dental prosthesis . . . xiii
1.1 Volume and enthalpy variation with temperature [12] . . . 3
1.2 Thermal dilatation (↵) and heat capacity cp variation - l=liquid, ls=undercooled liquid, c= crystal and v=glass [11] . . . 3
1.3 Influence of the rate of cooling (U in this Figure) on the glass transition tempera- ture: U1<U2<U3 [11] . . . 4
1.4 Micro-crystals and crystallite representation from (a) Frankenhein [19] (b) Lebedev [20] . . . 5
1.5 Schematic planar representation of (a) a crystalline form of RO2(a fourth oxygen would be located on each cation – (b) the respective vitreous form [10]– (c) Glass structure has a broader distribution of bond angles [24] . . . 6
1.6 Breaking of O-Si-O by a network modifier (Bridging O to Non-bridging O) [11] . . 9
1.7 Schematic planar representation of a vitreous network with both network-formers and modifiers [11] . . . 9
1.8 Estimation of the degree of ionicity of a bond from difference on electronegativity, a=cation, b=oxygen – The smallest amount of ionic bonds provides network forming cations [11] . . . 11
1.9 (a) Tissue-pathway model: presence of clusters and paths favoring ionic migration inside the tissue [14] (b) Modified random network in two dimensions: solid lines are covalent bonds and dotted lines ionic bonds, black atoms are modifiers, white atoms are formers and oxygen. Gray channels are domains enriched in network-modifiers were ionic diffusion occurs throughout the silicate network [30] . . . 13
1.10 Nucleation and growth rates for water [13] . . . 14
1.11 Nucleation and growth rates for silica [13] . . . 14
1.12 CCT-curves in a general case . . . 15
1.13 CCT-curves for water (a) and for silica (b) [13]- Rc is the cooling rate . . . 15
1.14 Crystallization treatment to form a glass-ceramic (a) Temperature dependence of nucleation and growth rate, metastable zone of undercooling and metastable zone of high viscosity (b) heat treatment stages: (1) glass melting, (2) glass shaping, (3) cooling, (4) nucleation step, (5) growth step . . . 17
1.15 Glass to glass-ceramic: (a) Nuclei formation, crystal growth and glass-ceramic microstructure (b) Surface crystallization [25] . . . 18 2.1 Phase transformations in glasses [36] . . . 21 2.2 Free energy (¢G) of a crystalline nucleus versus its radius (r) for T<Tm, volume
(¢Gv) and surface (¢Gs) contributions . . . 23 2.3 Change of the critical nuclear radius with the undercooling level of the melt and
the effect on the free energy (¢G) [39] . . . 23 2.4 Nucleation rate (I) as a function of temperature . . . 24 2.5 (a) Free energy versus radius of nuclei. The thermodynamic barrier for homoge-
neous nucleation is greater than for heterogeneous nucleation for the same critical radius - (b) The required undercooling for observable nuclei is smaller for hetero- geneous nucleation [39] (note this case is valid without kinetic limitation) . . . 26 2.6 (a) Formation of a solid cluster on a solid substrate with different wetting angles
[40] – (b) Geometrical factor£versus contact angle✓ [39] . . . 26 2.7 Epitaxial growth of Li2SiO3 on Li3PO4 [25] . . . 27 2.8 Growth mechanism controlled by the interface [11] - T< Tm . . . 28 2.9 Nucleation and growth rates for crystallization as a function of undercooling - the
maximum growth rate occurs at higher temperature than the maximum nucleation rate. The overlapping depends on the system considered . . . 30 2.10 Number of BaO.2SiO2nuclei on a crucible wall - scratched (s), normal (n), flame-
polished surface (f) and volume crystallization (v) [43] . . . 31 2.11 Schematic binary diagrams with (a) both stable and metastable liquid-liquid immis-
cibility and (b) entirely metastable immiscibility [44] . . . 32 2.12 Schematic phase diagrams – (a) Stable immiscibility– (b) Sub-liquidus immisicbility 34 2.13 (a) Gibbs energy variation in a binary system with a partial miscibility against com-
position. A variation of xb leads to a decrease of the Gibbs energy [52] - (b) Associated phase diagram delimiting the region of unmixing as well as the binodal and spinodal regions, T<Tc where Tc is the critical temperature for phase separa- tion [36] - (c) Decrease in Gibbs energy involving an amplification of the fluctuation leading to phase separation (grey region=spinodal region) - (d) Increase in Gibbs energy, absorbing the fluctuations (binodal region) [36] . . . 35 2.14 Composition change occurring during nucleation and growth and during spinodal
decomposition [55] and morphologies of (a) spinodal decomposition and (b) nucle- ation and growth [10] . . . 37
2.15 Thermodynamics "blocking" the formation of a stable phase. From a metastable phase L of composition c0, the more stable phase S of composition cs cannot form, as it would correspond to an increase in the free energy (A1B) until the phase L phase separates. The precipitation corresponds to a decrease in the free energy (A2B) [55] . . . 39 2.16 (a) Free energy against composition for a system exhibiting metastable phase sep-
aration (liquid) and a stable phase↵(solid) - (b) Variation of the thermodynamic driving force ¢G (DE in (a)) for a parent non separated glass (solid line) and a separated glass (dotted line) [5] . . . 41 2.17 Microstructure in low Al2O3-SiO2 glass-ceramic showing droplets crystallized in
mullite [32] . . . 43 2.18 Microstructure of mullite, growth is encompassed in phase-separated siliceous glass
[32] . . . 43 2.19 Controlled crystallization of La3F crystals using a amorphous phase separation [70] 44 3.1 Phase equilibrium data for the BaTiO3-SiO2 system [71] . . . 46 3.2 Compositions studied by Cleek and Hamilton and glass forming region in the BaO-
TiO2-SiO2 system [72] . . . 47 3.3 Eutectics and titanium solubility in the Ba2TiSi2O8-BaTiO3-TiO2 system [83] . . 48 3.4 BaO-TiO2-SiO2 system: data on crystal phases, liquidus surface and subsolidus [87] 49 3.5 Immiscibility, glass forming region and compositions studied in the BaO-TiO2-SiO2
system.[2] . . . 50 3.6 Immiscibility and glass forming region in the BaO-TiO2-SiO2 system. Triangle =
phase-separated; circle = transparent glass; cross = devitrified [91] - The cooling rate is not indicated . . . 50 3.7 Fresnoite structure projected on the (001) plane [78] . . . 51 3.8 Fresnoite structure along the [001]-direction or commonly named c-axis [93] . . . 51 4.1 Surface reference energy in a quaternary ABCD system . . . 57 4.2 Chemical potentials and common tangent construction to minimize the Gibbs en-
ergy of the system . . . 59 4.3 Illustration of the CALPHAD method from Kumar and Wollants [115] . . . 61 4.4 CALPHAD methodology - iterative assessment of the excess Gibbs energy of the
constituent sub-binaries are conducted for the extrapolation to higher-component systems [107] . . . 63 4.5 Gibbs energy for a solution phase and a line compound [107] . . . 64 4.6 Change in (a) ¢Hm and (b) ¢Gm for WH (a in the Figure)=0, >0 and <0 -
(¢Sm)=idSm . . . 68
4.7 Behavior of ex¢Gm/xAxB for different coefficients used in Redlich-Kister equation [119] . . . 70 4.8 Geometry of the Redlich-Kister polynomial in a binary system [117] . . . 70 4.9 Interpolation models: Kohler (symmetric) - Muggianu (symmetric) - Toop (asym-
metric) . . . 72 4.10 Body centred cubic structure with a preferential occupation of the atoms in the
body-centre and corner position [109] . . . 74 5.1 BaO-TiO2 phase diagram from Lu and Jin [128] . . . 78 5.2 SiO2-TiO2phase diagram calculated by: (1) Kaufman, (2) DeCapitani, (3) Kirschen
and (4) Kirillova [143]- Points are experimental data from Kirillova [143] . . . 80 5.3 : SiO2-TiO2 phase diagram calculated by FactSage 6.4 using the Quasi-Chemical
Model [130] . . . 80 6.1 Micrographs of samples with an increasing SiO2content before heat treatment . . 86 6.2 (a) Initial samples NoAPS49, NoAPS55, EUT and APS67, (b) samples obtained
after heat treatment and quenching . . . 86 6.3 Typical DTA scan on a BaO-TiO2-SiO2 glass . . . 88 6.4 Values of n and m for various crystallization mechanisms [165] . . . 89 7.1 Four lines including the 20 glass compositions studied – triangle=L1; square=L2;
cross=L3 and star=L4 [174] . . . 96 7.2 Calculated miscibility gap, experimental data and models in the SiO2-TiO2system
[174] – Experimental data from [89, 135, 139] – Models from [142, 143, 144, 145, 130] . . . 108 7.3 Calculated miscibility gap, liquidus with terminal phases and experimental data in
the SiO2-TiO2 system [174] – Experimental data from [143, 89, 133, 134, 135, 136, 137, 138, 139, 178, 140] . . . 108 7.4 SiO2 activity calculated at 1527, 1627 and 2527 °C [174] – experimental point at
1627 °C [164] . . . 108 7.5 yion (Y(ION,*) in the Figure) for Ti4+, SiO2, SiO44 and O2 species in the SiO2-
TiO2 system [174] . . . 109 7.6 Calculated metastable miscibility gaps without solid phases (set#1 and set#2) -
experimental data from [146, 88, 4] . . . 112 7.7 Calculated liquidus, terminal phases (set#1 and set#2) - experimental data from
[49] . . . 112 7.8 Calculated liquidus, terminal phases, intermediates phases - experimental data from
[49, 151, 152, 153, 154, 155, 156, 157, 158]- Models from [150, 129, 130] . . . . 113
7.10 Enthalpy of formation at 298K for the solids phases [174] – experimental data from [160, 161, 162] . . . 114 7.11 yion (Y(ION,*) in the Figure) for Ba2+, SiO2, SiO44 and O2 species in the BaO-
SiO2 system at 2727°C [174] . . . 114 7.12 Calculated liquid immiscibility using Muggianu’s interpolation from respective binary
descriptions along with the present experimental data at 1000°C – Green square:
Two phases and Red bow tie: one phase [174] . . . 115 7.13 TEM-EDX measurement on glass 11 heat treated for 30°C min at 1000 °C –
Amorphous bulk – (a) Droplets, (b) Matrix – Cu comes from the thin foil holder [174] . . . 116 7.14 Quantified EELS line-scan on glass 14, heat treated for 30 min at 1000 °C –
Amorphous bulk. The direction of the scan is indicated by an arrow on the inset HAADF-STEM image [174] . . . 116 7.15 Liquid immiscibility at 900 °C in the BaO-SiO2-TiO2 system along with experi-
mental data – Green square: two liquid phases; Red bow tie: single liquid phase [174] . . . 118 7.16 Liquid immiscibility at 1000 °C in the BaO-SiO2-TiO2 system along with experi-
mental data – Green square: Two liquid phases; Red bow tie: single liquid phase [174] . . . 118 7.17 Liquid-liquid immiscibility at 1300 °C in the BaO-SiO2-TiO2 system along with
experimental data – Green square: two phases; Red bow tie: one phase [174] . . . 118 7.18 Liquid-liquid immiscibility at 1500 °C in the BaO-SiO2-TiO2 system – no experi-
mental data [174] . . . 118 7.19 Calculated metastable liquid immiscibility on the Ba2TiSi2O8-SiO2 pseudo binary
(2x(BaO) - x(TiO2)=0) along with experimental data (green square: two phases, red bow tie: one phase) [174] . . . 119 7.20 Calculated metastable liquid immiscibility on the x(BaO) - x(TiO2)=0 line – no
experimental data [174] . . . 119 7.21 Calculated SiO2 activity on the 2x(BaO) - x(TiO2)=0 line for different tempera-
tures: 900, 1000, 1200, 1300, 1627 and 1900°C [174] . . . 120 7.22 Calculated SiO2 on the x(BaO) - x(TiO2)=0 line for different temperatures: 900,
1000, 1200, 1300, 1627 and 1900 °C [174] – Comparison with experimental data [164] . . . 120 7.23 Calculated miscibility gap at 1627 °C [174] and experimental point used to mea-
sure SiO2 activities in [45] – green points squares show a large positive deviation indicating the presence of phase separation – Glass 16 (circled green square) was investigated by TEM (see Figure 7.24) . . . 123 7.24 TEM observation of glass 16 (circled green square in Figure 7.23) heat treated at
1400 °C – Amorphous state and no phase separation [174] . . . 123
8.1 DTA on FRES – (25 - 112µm), (112 - 200µm), (200 - 800µm), > 800µm [182] 129 8.2 DTA on APS67 – (25 - 112µm) – 5°C/min, 10°C/min, 20°C/min, 30°C/min,
40°C/min [182] . . . 129
8.3 ln(-ln(1-x)) as a function of ln(heating rate) for T=925°C, 935°C and 945°C for APS67 composition (112 - 200µm) . . . 131
8.4 DTA on APS67-(112 - 200 µm)- 5 °C/min and 40 °C/min with and without a nucleation step at 760°C during 10 h. The discontinuity in the curve is due to the nucleation step at 760 °C - dotted lines correspond to the treatment prior to 760°C132 8.5 Activation energy for growth versus mean value of particle size interval for FRES , NoAPS49, EUT and APS67 – comparison between the present study (dotted line) and a previous study (triangle and rhombus) [2]– Data from [167] for FRES (black points) . . . 133
8.6 Microstructures of (a) FRES , (b) NoAPS49 , (c) EUT, (d) APS67 (bulk) and (e) APS67 (surface) heat treated at 1000°C during 72 h . . . 134
8.7 Microstructures of (a) FRES ,(b) NoAPS49, (c) EUT, (d) APS67 (bulk), (e) APS67 (bulk towards surface) and (f) APS67 (surface) heat treated at 1000 °C during 30 min . . . 135
8.8 XRD on FRES 1000°C 1 h - bottom (black) = surface, middle (red) = 100 µm and top (blue) = 190µm . . . 136
8.9 XRD on NoAPS49 1000 °C 1 h - bottom (black) = surface, middle (red) = 210 µm and top (blue) = 280µm . . . 136
8.10 XRD on EUT 1000°C 1 h - bottom (black) = surface, middle (red) = 210µm and top (blue) = 280 µm . . . 136
8.11 XRD on APS67 1000 °C 1 h - bottom (black) = surface, middle (red) = 200 µm and top (blue) = 500µm . . . 136
8.12 IO ratio as a function of the polishing depth for FRES (black), NoAPS49 (red), EUT (blue) and APS67 (green), compared with APS67 in powder (magenta) – Absorption depth: 2 µm at 30°and 6µm at 60°[182] . . . 137
8.13 (a) IQ EBSD map of FRES and (b) IPF EBSD map of FRES . . . 138
8.14 (a) IQ EBSD map of NoAPS49 and (b) IPF EBSD map of NoAPS49 . . . 138
8.15 (a) IQ EBSD map of EUT and (b) IPF EBSD map of EUT . . . 139
8.16 (a) IQ EBSD map of APS67 and (b) IPF EBSD map of APS67 . . . 139
8.17 (a) SEM micrograph of APS67 and (b) Corresponding IPF EBSD map of APS67 . 140 8.18 (a) IQ EBSD map of APS67 and (b) IPF EBSD map of APS67 . . . 140
8.19 (a) TEM micrograph of FRES and (b) corresponding crystallographic orientations observed with ACOM (Inverse Pole Figure and Index of Quality superimposed) . . 141 8.20 APS67 - (a) SEM micrograph, (b) TEM micrograph and (c) corresponding crys-
8.21 (a and c) TEM micrographs of APS67 – (b and d) corresponding crystallographic orientation maps observed with ACOM-TEM (Inverse Pole Figures) . . . 142 8.22 HAADF-STEM microstructures – (a) showing the absence of a clear transition re-
gion at the matrix/droplet interface in samples with amorphous matrix and droplets and (b) showing a "chemical" transition region at the matrix/droplet interface in samples with a crystallized matrix and amorphous droplets [182] . . . 143 9.1 Compositions studied, ranging from 49 to 70 mol% SiO2 and from 900 up to 1300
°C – Miscibility gap calculated using Thermo-Calc [174] – Liquidus from [87] and DTA analyses (this study) – Eutectic from Keding et al. [82] . . . 150 9.2 Direct annealing at 900, 1000, 1100, 1200 and 1300 °C from 5 min to 5 days . . . 151 9.3 Microstructures of (a) NoAPS55 and (b) APS70 obtained after a heat treatment
at 900°C during 5 days . . . 152 9.4 XRD patterns of APS55 (black) and APS70 (red) heat treated during 5 days -
fresnoite and "near-BaO.2SiO2" . . . 153 9.5 APS70 heat treated at 900 °C during 5 days – (a) microstructure, (b) diffraction
pattern in area 1 and (c) diffraction pattern in area 2 . . . 153 9.6 Microstructures of (a) NoAPS49, (b) NoAPS55, (c) EUT, (d) INTERM, (e)
APS67 and (f) APS70 heat treated at 1000°C during 1 h . . . 155 9.7 Microstructures of (a) NoAPS55 and (b) APS67 heat treated at 1000 °C during
24 h . . . 156 9.8 Microstructures of (a) NoAPS55, (b) EUT,(c) INTERM (surface) and (d) APS67
(bulk) heat treated at 1000°C during 72 h . . . 157 9.9 Microstructure of APS67 obtained after a heat treatment at 1000 °C during 24 h
– HAADF-STEM image and averaged compositions over the region indicated by the green rectangle, averaged over the Y direction. . . 158 9.10 XRD patterns of NoAPS49 (black), NoAPS55 (red), INTERM (blue), EUT (green),
APS67 (magenta) and APS70 (brown) heat treated at 1000°C – (a) 24 h and (c) 72 h - fresnoite, cristobalite and BaO.2SiO2 . . . 159 9.11 Bulk microstructures of APS67 heat treated at 1000°C – (a) 30 min, (b) 1h, (c)
24 h and (d) 72 h . . . 160 9.12 Surface microstructures of APS67 heat treated at 1000 °C – (a) 30 min, (b) 1h,
(c) 24 h and (d) 72 h . . . 161 9.13 Microstructure of APS70 obtained after a heat treatment at 1000°C during 24h -
Interface between cristobalite and eutectic fresnoite . . . 162 9.14 Microstructures of (a) NoAPS49, (b) EUT and (c) APS67 obtained after a heat
treatment at 1100°C during 5 min . . . 163 9.15 Microstructures of (a) NoAPS49, (b) EUT, (c) INTERM, (d) APS67 and (e)
APS70 obtained after a heat treatment at 1100 °C during 1 h . . . 164
9.16 XRD patterns of NoAPS49 (black), NoAPS55 (red), INTERM (blue), EUT (green), APS67 (magenta) and APS70 (brown) heat treated at 1100 °C 1 h – Fresnoite and cristobalite . . . 165 9.17 Microstructures of (a) NoAPS49, (b) NoAPS55, (c) EUT, (d) INTERM, (e)
APS67 and (f) APS70 heat treated at 1100°C during 24 h . . . 166 9.18 XRD patterns of NoAPS49 (black), NoAPS55 (red), INTERM (blue), EUT (green),
APS67 (magenta) and APS70 (brown) heat treated at 1100 °C 24 h – Fresnoite and cristobalite . . . 167 9.19 TEM micrographs of APS67 heat treated at 1100°C during 24h (right: magnification)167 9.20 Microstructures of (a) NoAPS49, (b) NoAPS55, (c) EUT, (d) INTERM, (e)
APS67 and (f) APS70 heat treated at 1200°C during 1 h . . . 169 9.21 Microstructure of APS70 heat treated at 1200°C during 30 min - Front between
crystal and amorphous phase separation . . . 170 9.22 XRD patterns of NoAPS49 (black), NoAPS55 (red), INTERM (blue), EUT (green),
APS67 (magenta) and APS70 (brown) heat treated at 1200 °C 1 h – Fresnoite and cristobalite . . . 170 9.23 TEM micrographs of APS67 heat treated at 1200°C during 1 h and (c) correspond-
ing orientations for cristobalite observed with ACOM-TEM (Inverse pole figure and index of quality superimposed) . . . 171 9.24 Microstructures of (a) NoAPS49 and (b) APS70 heat treated at 1300°C during 1 h171 9.25 XRD patterns of NoAPS49 (black) and APS70 (red) heat treated at 1300°C during
1h - Fresnoite is the only crystal phase for NoAPS49 and cristobalite for APS70 . 172 9.26 BaO-TiO2-SiO2 system – Miscibility gap (MG) at 1000 °C - Composition shifts
involved by cristobalite, fresnoite or needles formations – only the formation of fresnoite stabilizes the amorphous phase separation. . . 174 10.1 Heat treatments performed: (a) SH and RH up to 1000°C or 1200°C and subse-
quent annealing during 0, 1 and 24 h, (b) SC and RC down to 1000 and 1200 °C and subsequent annealing during 0, 1 and 24 h, (c) RH with a first isothermal step at 1000°C during 24 or 48 h and a second isothermal step at 1200°C during 24 h and (d) SC with first isothermal step at 1200°C during 5 h followed by a second isothermal step at 1000 °C during 24 h . . . 179 10.2 Microstructures of NoAPS55 – (a) SH up to 1000 °C without annealing (border
with the amorphous bulk), (b) RH up to 1000 °C without annealing (border with the amorphous bulk), (c) SH up to 1000°C , annealing for 1 h, (d) RH up to 1000
°C , annealing for 1 h . . . 180 10.3 Microstructure of NoAPS55 after SC and annealing at 1000°C during 1 h . . . . 181
10.4 XRD patterns of NoAPS55 – (a) No annealing: SH up to 1000°C (black), RH up to 1000 °C (red) and SC down to 1000 °C (blue)– (b) Annealing for 1 h: SH up to 1000 °C (black), RH up to 1000 °C (red), direct annealing at 1000 °C for 1 h (blue) and SC down to 1000 °C (green) . . . 182 10.5 Microstructures of APS67 – (a) SH up to 1000 °C without annealing (surface),
(b) magnification of the highlighted area, (c) RH up to 1000°C without annealing (surface) and (d) RH up to 1000°C without annealing (bulk) . . . 183 10.6 Microstructures of APS67 – (a) RC down to 1000°C without annealing - (b) SC
down to 1000°C without annealing . . . 184 10.7 Microstructures of APS67 - (a) RC down to 1000 °C, annealing for 1 h - (b) SC
down to 1000°C, annealing for 1 h . . . 184 10.8 Microstructures of APS67 – (a) RC down to 1000°C, annealing for 24 h - (b) SC
down to 1000°C, annealing for 24 h . . . 185 10.9 Microstructures of APS67 – (a) Cooling from the liquid state down to 1200°C,
annealing for 5 h, cooling down to 1000 °C and subsequent annealing for 24 h - (b) magnification of (a) . . . 185 10.10APS67- "Gradient" of morphologies during SC down to 1000°C . . . 186 10.11XRD patterns of APS67 - (a) SH (black) and RH (red) up to 1000 °C – no
annealing, (b) zoom for SH (black) and RH (red) up to 1000°C and annealing for 1 h compared with and direct annealing for 1 h (blue) . . . 187 10.12XRD patterns of APS67 – (a) RC down to 1000 °C – no annealing (black), an-
nealing for 1 h (red), annealing for 24 h (blue) and (b) SC down to 1000°C – no annealing (black), annealing for 1 h (red), annealing for 24 h (blue) . . . 188 10.13Microstructures of APS67 - (a) SH up to 1200°C, (b) RH up to 1200°C (c) SC
down to 1200°C - no subsequent annealing . . . 188 10.14Microstructures of NoAPS55 – (a) RH up to 1200°C, annealing for 1 h (b) direct
annealing at 1200°C during 1 h . . . 189 10.15Microstructures of NoAPS67 – (a) RH up to 1200°C, annealing for 1 h (b) direct
annealing at 1200°C during 1 h . . . 190 10.16Microstructures of APS67 – direct annealing at 1200°C for 24 h – (a) heating from
room temperature up to 1200 °C, annealing for 24 h (b) direct annealing during 24 h(c) heating from room temperature up to 1000 °C during 24h (prior step) + annealing at 1200 °C for 24 h (c) heating from room temperature up to 1000 °C during 48h (prior step) + annealing at 1200°C for 24 h . . . 191 10.17(a) Microstructures of (a) NoAPS55 and (b) APS67 obtained after SC down to
1200 °C and annealing for 24 h . . . 192
10.18XRD patterns of APS67 - RH up to 1000°C during 48 h (black); RH up to 1000
°C during 24 h and up to 1200°C 24 h (red); RH up to 1000°C during 24 h and up to 1200 °C during 24 h (blue); RH up to 1200°C during 24 h (green); direct annealing at 1200 °C during 24h (magenta); SC down to 1200 °C during 24 h (brown)Zoom between 17 and 27 ° - Different values between 1000 and 1200 °C
for the c-axis of cristobalite . . . 192
11.1 Bright field TEM and HRTEM microstructures of APS67 heat treated at 1000°C during 30 min . . . 197
11.2 TEM microstructure of INTERM obtained after a heat treatment at 1000°C during 24h – (a) needles, (b) interface and (c) fresnoite . . . 198
11.3 TEM diffraction pattern – (a) Needles, (b) Interface between needles and fresnoite and (c) fresnoite . . . 198
11.4 HAADF-STEM image of eutectic fresnoite along [001] with overlaid structural model (Red=Ba, blue= Ti, green=Si and magenta=O). The image simulation was calculated using lattice parameters and crystal symmetry of stoichiometric fresnoite from Masse et al. [77] . . . 200
11.5 Correlation between the values of the c-axis of cristobalite and its resulting mor- phology, for heat treatments ranging from 1000 up to 1300°C and over the whole range of compositions . . . 202
11.6 Case 1 : Short annealing time- RH/SH, direct annealing (all compositions) or RC (hyper-eutectic compositions) . . . 205
11.7 Case 2 : Long annealing time- RH/SH, direct annealing (all compositions) or RC (hyper-eutectic compositions) . . . 205
11.8 Case 3: Short annealing time – SC/RC (hypo-eutectic compositions) . . . 205
11.9 Case 4: Long annealing time – SC/RC (hypo-eutectic compositions) . . . 205
11.10Case 5 – Short/long annealing time – SC (hyper-eutectic compositions) . . . 206
12.1 Visible photoluminescence effect - (a) FRES, NoAPS49 and APS67 heat treated at 1000 °C, (b) NoAPS49 and APS67 heat treated at 1000 °C compared with amorphous APS67 and (c) APS67 samples compared after different heat treatments.209 12.2 Microstructures of NoAPS55 – (a) RH up to 1000°C, annealing for 48 h, (b) RH up to 1200 °C, annealing for 24 h and (c) RH up to 1000 °C, annealing for 48 h (prior step) followed by annealing at 1200°C for 24 h . . . 209
12.3 Microstructures of EUT – (a) RH up to 1000°C, annealing for 48 h, (b) RH up to 1200 °C, annealing for 24 h and (c) RH up to 1000 °C, annealing for 48 h (prior step) followed by annealing at 1200°C for 24 h . . . 210
12.4 Microstructures of APS67 – (a) RH up to 1000°C, annealing for 48 h, (b) RH up to 1200°C, annealing for 24 h and (c) RH up to 1000°C, annealing for 48 h (prior step) followed by annealing at 1200°C for 24 h . . . 210 12.5 Microstructures of APS70 – (a) RH up to 1200°C, annealing for 24 h and (b) RH
up to 1000°C, annealing for 48 h (prior step) followed by annealing at 1200°C for 24 h . . . 210 12.6 XRD patterns of NoAPS55 (black, red and blue), EUT (green, magenta and
brown), APS67 (cyan, grey and dark green) and APS70 (mauve and turquoise) after (i) RH up to 1000 °C and annealing during 48 °C, (ii) up to 1200 °C and annealing during 24 h and (iii) up to 1000 C°, annealing during 48 h followed by second annealing at 1200°C during 24 h, respectively . . . 211 12.7 Photoluminescence intensity of NoAPS55, EUT, APS67 and APS70 excited at 254
nm – (a) heat treatment at 1000 °C during 48 h and (b) heat treatments at 1200
°C during 24 h with/without a prior step at 1000°C during 48 h . . . 212 13.1 (a) Immiscibiliy region [194] and industrial composition in the Na2O-CaO-SiO2
system . . . 215 13.2 (a) Immiscibiliy region and liquidus in the SiO2-rich part of the diagram [195] and
(b) liquidus and solid phases [196] . . . 217 13.3 (a) Miscibility gap [194] and (b) liquidus with solid phases in the Na2O-CaO-SiO2
system [196] . . . 218 13.4 Thermal treatments conducted for soda-lime-silica glasses - TAP S,dev elopmentand
Tcr y stalliz ation are specific to each composition . . . 220 13.5 Viscosity for glass compositions investigated and pure SiO2- Line: FactSage, Point:
Tg calculated with GlassViscCalc . . . 223 13.6 Bin - (a) XRD patterns of untreated sample (black) and after a DTA run from
room temperature up to 1300°C at 20°C/min (red) and (b) microstructure of Bin (powder) after the same DTA run . . . 225 13.7 Microstructures of Bin (powder) - (a) heat treated for 10h at 680 °C, (b) heat
treated for 1h at 680 °C and for 5 min at 750°C, (c) heat treated for 5 min at 750°C . . . 225 13.8 XRD patterns of Bin heat treated at 680°C during 10 h (black), with an additional
step at 750°C (red) and at 750 °C 5 min without prior step (red) . . . 226 13.9 Microstructures of (a) Bin (powder) heat treated at 750 °C for 1h and (b) Bin
(bulk) heat treated at 680°C for 10h followed by 760°C for 4h . . . 227 13.10Microstructures of Bin heat treated (a) during 1h at 950°C without step at 680°C
(center) (b) during 10h at 680°C followed by 1h at 950°C (surface) and (c) during 10h at 680°C followed by 1h at 950°C (center) . . . 227
13.11XRD patterns of Bin after a heat treated at 950 °C during 1h with a step at 680
°C during 10 h (black) and without step (red) . . . 228 13.12Ter - (a) Microstructure after a heat treatment at 710°C during 1h – (b) Macro-
graphs of untreated and treated samples, opalescence due to phase separation . . 228 13.13Droplets diameter versus time at 740°C – respective samples and/or microstructures229 13.14Ter heat treated at 740°C during 1h and at 810°C during 20 min – TEM mi-
crostructure, Ca mapping and EDX analysis . . . 230 13.15Microstructure of Ter heat treated from room temperature up to 1000 °C during
1 h - devitrite (Na2O.3CaO.6SiO2), low-cristobalite (SiO2) and tridymite (SiO2) . 230 13.16Microstructures of Ter heat treated at (a) 760 °C during 2 h, (b) 830 °C during
16 h, (c) 1000 °C during 1h and (d) 1000°C during 5h . . . 231 13.17XRD patterns of Ter (a) phase encountered from 760 up to 1000°C: heat treated
at 760°C during 2h (black), at 830°C during 16 h (red) at 1000°C during 1 h (blue) and during 5 h (green) – (b) phase separation development and crystallization: 680
°C during 30 min (black), 5 h (red) and 48 h (blue) and crystallization at 1000°C during 1 h . . . 232 13.18Macrographs of Ter heat treated at 760°C during 24 h and at 1000°C from 0 to
60 min. Quenching and slow cooling after annealing . . . 232 13.19Microstructures of Ter – (a) surface and (b) bulk . . . 233 13.20Microstructures of Ter-LowSiO2– (a) surface and (b) bulk . . . 234 13.21Microstructures of Ter-HighSiO2 heat treated at (a) 830 °C during 3 h, (b) 650
°C during 4 h followed by 900°C during 1 h, (c) 1000 °C during 1 h, (d) 1050°C during 1 h and (e) 1200 °C during 1 h . . . 235 13.22XRD patterns of Ter-HighSiO2 heat treated at 800 °C during 3 h (black), at 650
°C during 4 h and during 1 h at 900°C (red), 1000°C (blue), 1050°C (green) and 1200 °C (magenta). . . 236 13.23Macrographs of Ter-CaO-1 heat treated (a) during 14 h at 700°C, (b) during 2 h
at 760°C, (c) during 2 h at 680°C . . . 237 13.24Macrographs of Ter-CaO-2 heat treated (a) during 2 h at 760 °C, (b) during 2 h
at 760 °C followed by 1 h at 870°C, (c) during 2 h at 760 °C followed by 1 h at 890°C and (d) cross-section of (c) . . . 237 13.25XRD patterns of Ter-CaO-1 heat treated (a) at 800 (black), 830 (red) and 900
°C (blue) with the formation of devitrite, wollastonite and cristobalite and (b) heat treatment at 1000 °C during 1 h (black) and 24 h (red) with the formation of evitrite, wollastonite, cristobalite and tridymite . . . 238 13.26XRD patterns of Ter-CaO-2 heat treated (a) at 800°C (black), 830°C (red) and
900 °C (blue) with the formation of devitrite, wollastonite and cristobalite and
13.27Schematic summary of the experiments conducted on the compositions Ter, Ter- lowSiO2 and Ter-CaO1 – Effect of oxides addition on phase separation and crys- tallization . . . 240 13.28XRD patterns of Ter-CaO1 (black), Ter-CaO1+2%BaO (red), Ter-CaO1%TiO2
(blue) and Ter-CaO1+2%ZrO2 (green) heat treated for 2 h at 760°C followed by 1 h at 830°C . . . 241 13.29Immiscibility area - binodal and spinodal areas with their associated microstructures
for the Na2O-SiO2 system [205] . . . 242 13.30Microstructures of Bin-Spin heat treated at (a) 650°C during 80 min, (b) 650°C
during 320 min, (c) 650°C during 17 h and (d) 770°C during 15 min . . . 243 13.31Devitrite grow rate with temperature, phase separation temperature range and
temperatures of crystallization investigated for an industrial soda-lime silica glass [206] . . . 244 13.32(a) Miscibility gaps (a) in the Na2O-CaO-SiO2 system [194] and (b) in the BaO-
TiO2-SiO2 system calculated using Thermo-Calc (see Chapter 4) . . . 245 13.33Devitrite and wollastonite growth rates in an industrial soda-lime silica glass [206] . 246 13.34Superposition of immiscibility area and solid phases in the Na2O-CaO-SiO2system
[194, 196] . . . 246 14.1 Amorphous phase separation and cristobalite in (a) the BaO-TiO2-SiO2 and (b)
the Na2O-CaO-SiO2 . . . 251 14.2 Distance between Tg and the eutectic temperature - (a) large distance allowing
phase separation with the crystallization of the disilicate and (b) small distance where SiO2 polymorphs cristallization will be observed. . . 252 14.3 Distance between binodal curve and stoichiometric composition . . . 253 A.1 Tg versus Tm for several base compositions – Compositions which form glasses
have a ratio about 2/3 [11] . . . 280 A.2 Maximum nucleation rates against Tg,r for 55 glasses of stoichiometric composi-
tions and non-stoichiometric compositions in the following systems [214] (b) Time- lag at the temperature of maximum nucleation rate as a function of Tg,r [41] . . . 281 A.3 UMaxagainst Tg,r for 20 glasses of stoichiometric compositions and non-stoichiometric
compositions in different systems [214] . . . 281 A.4 (a) Frequency distribution histogram of experimentally observed TTmg for 108 typical
inorganic glass-formers. (b) Frequency distribution histogram of 80 experimental
Tg
Tm for metallic glass-forming alloys [41] . . . 282 A.5 (a) The densities of both glass and crystalline phases (b) SiO2 polymorphs . . . . 283 B.1 Phase diagram for alkali and alkaline-earth oxide-silica systems [159] . . . 285
B.2 Immiscibility boundaries for alkali and alkaline earth silicate systems [45] - RnO=Na2O, BaO, MgO, CaO, ... . . 285 B.3 (a) Correlation between ionic potential dZacc and extend of the liquid miscibility gap
in a number of metal oxide-silica systems (b) schematic phase diagrams showing the different types of immiscibility with dZacc 3 and dZacc<3 [224] . . . 287 B.4 (a) Consolute temperature against Zac [46]; (b) Consolute temperature against dZacc
[47]; . . . 290 C.1 Crystallization of 20%mol Li2O-80mol% SiO2[20] . . . 291 C.2 Pyroceram glass tempered for 30 min at 760°C – crystallization within the droplets
[20] . . . 291 C.3 Crystallization in the droplet zones with fracture tail in a fluorosilicate glass. Crys-
tallization does not extend to the surrounding glass [20] . . . 292 C.4 Crystallization inside the droplets [20] . . . 292 C.5 Microstructures of (a) MgO-Al2O3-SiO2-TiO2(b) Li2O-CaO-SiO2-TiO2(c) Li2O-
MgO-Al2O3-SiO2 [64] . . . 293 C.6 Composition shifts in the Na2O-BaO-SiO2 caused by phase separation and crystal-
lization [60] . . . 294 C.7 Simplified concentration profile of the diffusion zone and the corresponding particle
shell structure with a nucleus [66] . . . 295 C.8 Na/Nb and Ua/Ub for various oxides. Na and Nb are the nucleation rates in the
25Li2O.75%SiO2 , 3ROn and 33Li2O,75%SiO2, 3ROn, Uaand Ub are the crystal growth rates [65] . . . 296 C.9 Heat treated sample containing silver - Ag particles are observed only in the SiO2-
rich droplets [63] . . . 297 C.10 Nucleation process of a silver particle is enhanced by phase separation: (a) early
stage of the phase separation, (b) advanced stage, (c) nucleation of silver particle on the surface of the droplets [63] . . . 297 C.11 Number of crystals per unit volume in Li2O-SiO2 glasses heat treated for 8 h at
different temperatures [7] . . . 298 C.12 Number of crystals per units volume and number of amorphous droplets per unit
area of 29% Li2O as a function of nucleation temperature [7] . . . 298 C.13 Plot of log10 Nv(m 3) against nucleation temperature during 1h – Nvis the number
of internally nucleated spherulites of crystalline barium disilicate per unit volume - 25.3%mol BaO; 27.4%mol BaO; 28.7%mol BaO; 30.4%mol BaO; 33.1%mol BaO [4] . . . 300
C.14 Samples heat treated at 700 °C up to 20 h - (a) Number of internally nucle- ated crystals and (b) nucleation rate in glass 25.3%mol BaO at 700 °C - rapidly quenched, quenched (as quenched phase separation), 800 °C 1h, 900°C 1h (prior phase separation development) [5] . . . 301 C.15 Integrated SAXS intensity Q for BaO-SiO2 glasses heat treated at 743 and 760°C
against time of heat treatment [6] . . . 302 C.16 SEM images of glass-ceramics (a) and (b) no phase separation (c) and (d) crys-
tallization with phase separation [2] . . . 303 C.17 Change in activation energy from the modified Kissinger plot with respect to the
specific surface area of the samples [3] . . . 303 D.1 Polarization microscopy from surface crystallized glasses of (a) Ba2TiGe2O8, (b)
Ba2TiSi2O8 and (c) Sr2TiSi2O8 and heat treated at Tg [252] . . . 306 D.2 SHG for Ba2TiSi2O8 heat treated at (a) 740, (b) 760 and (c) 780 °C with an
incident laser light ( =1064nm) [105] . . . 306 D.3 Enhancement of the photoluminescence intensity using different annealing temper-
atures during 1 h [105] . . . 307 D.4 Change in photoluminescence intensity at 467 nm versus SiO2 concentration. [2] . 308 D.5 Photoluminescence spectra of Ba2TiSi2O8, Ba2TiSi2O8+0.88 SiO2and Ba2TiSi2O8+4.1SiO2
[2] . . . 308
List of Tables
1 Glass compositions comparison between Antiquity and nowadays [1] . . . xii 5.1 Thermodynamic properties of the liquid phase in the Si-Ti-O system [128] . . . 78 5.2 Thermodynamic properties of the terminal phases in the Si-Ti-O system [128, 124] 81 5.3 Thermodynamic properties of the terminal phases in the Ba-Si-O system [128, 124] 82 5.4 Samples – glass appearance – target compositions calculated from the powder mix
and analysed compositions . . . 83 6.1 Optimized EBSD settings for SU-Hitachi FEG-SEM . . . 92 7.1 Glass compositions investigated – error =±0,4 mol% (XRF error on one sample)
[174] . . . 97 7.2 Thermodynamic properties of the intermediate solid phases in the Ba-Si-O system 103 7.3 Thermodynamic properties of the liquid phase in the Si-Ti-O system [174] . . . 107 7.4 Thermodynamic properties of the liquid phase in the Ba-Si-O system considering
liquid phase and end members data only - set#1 . . . 110 7.5 Thermodynamic properties of the liquid phase in the Ba-Si-O system taking liquid
phase, end members and solid phases data into account - set#2 [174] . . . 110 7.6 Thermodynamic properties of the intermediate solid phases in the Ba-Si-O system
[174] . . . 111 7.7 Thermodynamic properties of the liquid phase in the Ba-Si-Ti-O system [174] . . . 116 8.1 Sample names – glass appearance – target compositions (calculated from the pow-
der mix, see Appendix F for APS67) and effective analysed compositions together with the experimental error calculated from measurements on several samples . . . 127 8.2 Tg,Tx, Tp, Tm,e and Tmfor compositions on Ba2TiSi2O8-SiO2line - DTA; (112-
200µm), 10°C/min . . . 128 8.3 Tp (°C) as a function of the granulometries (at 20°C/min) for FRES, NoAPS49,
EUT and APS67 . . . 130 8.4 Tp ( °C) as a function of the heating rate for (25-112µm) . . . 130 8.5 Avrami parameters as a function of particle size (G) for FRES, NoAPS49, EUT
and APS67 [182] . . . 132
9.1 Sample names – glass appearance – target compositions (calculated from the pow- der mix, see Appendix F for APS67) and effective analysed compositions together with the experimental error calculated from measurements on several samples . . . 149 9.2 Tg, Tx, Tm,e and Tmfor compositions on the Ba2TiSi2O8-SiO2 line - DTA; (112-
200µm), 10°C/min . . . 151 11.1 The 14 scenarii can be divided into 5 different groups leading to a specific metastable
phase diagram . . . 204 13.1 Glasses compositions in %wt . . . 218 13.2 Ter, Ter-lowSiO2 and Ter-CaO1 with different amounts of added oxides - thermal
treatments . . . 221 13.3 Tg of glass compositions investigated (error =±4°C) . . . 222 13.4 Hardness, brittleness, Tg and CTE of Ter untreated, with phase separation and
after cristobalite formation. Comparison with an AGC classical composition . . . . 223 14.1 Glass systems (BS=BaO-SiO2, LS=Li2O-SiO2, BTS=BaO-TiO2-SiO2, NS=Na2O-
SiO2 and NCS=Na2O-CaO-SiO2) and criteria investigated to study the interplay between phase separation and crystallization . . . 254
