HAL Id: jpa-00224314
https://hal.archives-ouvertes.fr/jpa-00224314
Submitted on 1 Jan 1984
HAL is a multi-disciplinary open access archive for the deposit and dissemination of sci- entific research documents, whether they are pub- lished or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers.
L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d’enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
ROUND TABLE - METROLOGY
J.M. Besson (moderator)
To cite this version:
J.M. Besson (moderator). ROUND TABLE - METROLOGY. Journal de Physique Colloques, 1984, 45 (C8), pp.C8-79-C8-80. �10.1051/jphyscol:1984816�. �jpa-00224314�
J O U R N A L DE PHYSIQUE
C o l l o q u e C 8 , s u p p l e m e n t a u n O 1 l , T o m e 45, n o v e m b r e 1984 p a g e c 8 - 7 9
ROUND TABLE METROLOGY
J.M. B e s s o n ( M o d e r a t o r )
MiZiem Tr8s Condense's - Lf.A. 7 8 2 , Tour 1 3 E4, UniversitE Pierre e t Marie Curie, 4 pZace Jussieu, 75230 Paris Ceder 0 5 , France
The g e n e r a l theme o f t h e d i s c u s s i o n was t h e p r o s p e c t i v e means o f i n c r e a s i n g t h e a b s o l u t e a c c u r a c y o f t h e p r e s e n t p r a c t i c a l p r e s s u r e s c a l e a b o v e 1 . 4 G P a w i t h a t - t e n t i o n t o t r a n s f e r g a u g e s s t a n d a r d s ( e . g . r u b y f l u o r e s c e n c e s c a l e ; . A s r e g a r d s t h e f i r s t t o p i c t h a t i s i m p r o v e d a c c u r a c y o f t h e lPPS ( I n t e r n a t i o n a l P r a c t i c a l P r e s s u r e s c a l e , two a s p e c t s w e r e d i s c u s s e d : i n d i r e c t ( c o m p u t a t i o n a l j and d i r e c t m e t h o d s . a ) I n d i r e c t m e t h o d s .
F i r s t p r i n c i p l e s e q u a t i o n s o f s t a t e c a n be u s e d t o o b t a i n a d e f i n i t i o n o f p r e s s u r e t h r o u g h comp;tation o f f r e e e n e r g y . E.O.5 o f s o d i u m c o u l d be a c c u r a t e w i t h i n 1 0 % on
A V / V O a t 50 GPa. Na C1 c o u l d a l s o be a good c a n d i d a t e , d e s p i t e i t s t r a n s i t i o n t o B2 a b o v e 29.2 GPa, b u t c a l c u l a t i o n s a b o v e t h i s p r e s s u r e show s i g n i f i c a n t d i s c r e p a n - c i e s . O t h e r s y s t e m s m i g h t be m e t a l s (Au) o r o x y d e s .
A n o t h e r a p p r o a c h may b e t o c o m p u r t e t h e v i b r a t i o n a l modes o f a s i m p l e Raman-active s y s t e m w i t h h i g h b u l k modulus ( d i a m o n d ) . I d e n t i f i c a t i o n o f t h e Raman s h i f t o f a h y d r o s t a t i c a l l y s t r e s s e d diamor)d s a m p l e w i t h i n diamond c e l l r l o w a p p e a r s f e a s i b l e . F i n a l l y , i n t h e r a n g e o f 100 GPa o r h i g h e r , p r o g r e s s i n s h o c k m e t h o d s , w i t h d i r e c t t e m p e r a t u r e m e a s u r e m e n t s may l e a d t o a n a c c u r a c y o f " 5 % on t h e a b s o l u t e p r e s s u r e . b ) D i r e c t m e t h o d s
D i r e c t m e t h o d s a r e b a s e d e i t h e r I n t h e f o r c e - o e r - u n i t - a r e a d e f i n i t i o n o f p r e s s u r e . o r upon i n d e p e n d e n t m e a s u r e m e n t s o f c o m p r e s s i b i l i t y a n d volume c h a n g e s , p r e f e r a b l ; i n t h e diamond a n v i l c e l l .
The f i r s t method which i s p r a c t i c a l l x u s e d up t o now below 2 GPa(dead w e i g h t p i s t o n g a u g e s ) p r o v i d e s a n a c c u r a c y o f " 10- . I t m i g h t i n t h e f u t u r e , b e u s a b l e o v e r a much l a r g e r r a n g e o f p r e s s u r e ( " 1 0 GPa ? ) i f S y n d i t e p i s t o n - c y l i n d e r d e v i c e s p r o v e
u s a b l e . A l t h o u g h t h i s i s , a t t h e p r e s e n t , o n l y a p o s s i b i l i t y , t h i s would be a m a j o r c o n t r i b u t i o n t o t h e IPPS.
The combined v o l u m e - c o m p r e s s i b i l i t y method w i l l r e q u i r e improvement o f X-ray m e t h o d s and m e a s o r e m e n t s o f t h e e l a s t i c c o r l s t a n t s t e n s o r u e l l above 1 0 GPa. C r y s t a l p a r a - m e t e r s c a n now be m e a s u r e d , w i t h s y n c h r o t r o n r a d i a t i o n , w i t h a p r e c i s i o n o f and p o s s i b l y E l a s t i c c o n s t a n t s c a n be o b t a i n e d by B r i l l o u i n s c a t t e r i n g on s i m p l e s y s t e m s , b u t t h e r e q u i r e d p r e c i s i o n o f 10-3 i n t h e B r i l l o u i n s h i f t is s t i l l d i f f i c u l t t o o b t a i n . Now t h a t e l e c t r i c a l m e t h o d s c a n b e u s e d i n t h e diamond a n v i l c e l l on m o n o c r y s t a l s i n a h y d r o s t a t i c e n v i r o n m e n t ( t h i s c o n f e r e n c e ) u l t r a s o n i c methods a r e e n t i r e l y c o n c e i v a b l e i n t h e n e a r f u t u r e , a n d would g i v e t h e n e c e s s a r y p r e c i s i o n . T h i s s t i l l r e q u i r e s a t e c h n o l o g i c a l e f f o r t .
c ) The f l u o r e s c e n c e s c a l e (Ruby e m i s s i o n l i n e )
D e s p i t e i t s d r a w b a c k s , t h e r u b y (A1203 : C r j C ) f l u o r e s c e n c e s c a l e s t i l l r e m a i n s t h e m o s t p r a c t i c a l a n d w i d e l y u s e d s e c o n d a r y s t a n d a r d . I t s h o u l d be compared w i t h o t h e r l u m i n e s c e n c e s t a n d a r d s s u c h a s diamond f o r i n s t a n c e , u h i c h i s a m e n a b l e t o Raman, B r i l l o u i n , and X-ray m e a s u r e m e n t s and more e a s i l y t r a c t a b l e by c a l c u l a t i o n .
C o m p a r i s o n s o f t h e r u b y e m i s s i o n w i t h o t h e r f l u o r e s c e n t materials s h o u l d a l s o be d o n e . Examples would be ~ i 3 + -doped A12 O3 f o r low t e m p e r a t u r e s o r Eu-doped YAG f o r h i g h t e m p e r a t u r e s .
R e p r o d u c i b i l i t y o f t h e f l u o r e s c e n c e s c a l e c a n be o b t a i n e d o n l y by s t a n d a r d i z a t i o n o f c r y s t a l s a m p l e s a s r e g a r d s a c t i v e s i t e c o n c e n t r a t i o n , c r y s t a l s y n t h e s i s m e t h o d s t h e r m a l h i s t o r y , a n d i l l u m i n a t i o n c o n d i t i o n s .
Article published online by EDP Sciences and available at http://dx.doi.org/10.1051/jphyscol:1984816
C8-80 JOURNAL DE PHYSIQUE
Conferees o f 17 i n s t i t u t i o n s ( l i s t below) have expressed i n t e r e s t i n keeping i n touch w i t h the moderator t o g e t i n f o r m a t i o n and c h a r a c t e r i z e d standard ruby samples
ADAMS D.M.
Department o f Chemystry The U n i v e r s i t y
LEICESTER L E I 7RH GRANDE BRETAGNE
HOLZAPFEL W.B.
Uni-GH Paderborn
Fachbereich 6-Experimentalphys.
Warburgerstr. 100 D - 4790 PADERBORN
BENEDICT U. LEGER J.M.
I n s t i t u t EuropCen des Transuraniens E.R. 211 CNRS P o s t f a c h 2266 1, Place A. B r i a n d
D - 7500 KARLSRUHE 1 92190 MEUDON
BERNIER H.; VEZIN R. NELLIS W.J.
CEA L i m e i l - V a l e n t o n LLNL
BP 27 L-387
94190 VILLENEUVE S T GEORGES LIVERMORE CA 94550 USA
COSTANTINI J.M.
BP 12 NICOL M.
91680 BRUYERES LE CHATEL Deot. o f Chemistry
DRIESSEN A. u.'c.L.A.
LOS ANGELES. CA 90024 V r i j e U n i v e r s i t e i t U.S.A.
Natuurkunding Laboratorium
De B o l e l a a n 1081 PEYRONNEAU J.
1081 HV AMSTERDAM L a b o r a t o i r e G6omatCriaux
NEOERLAND IPG Tour 14
FABRE D. ; J.P. PETlTET LIMHP
U n i v e r s i t 6 de P a r i s Nord 93430 VILLETANEUSE FUKUNAGA 0.
1-1 NAMIKI, SAKURA-MURA NIIHARI-GUN
IBARAKI 305 JAPON HATTON P.D.
Science and E n g i n e e r i n g Research C o u n c i l Daresbury L a b o r a t o r y UARRINGTON WA4 4AD Grande Bretagne
HOCHHEIMER H.D. ; M. KOUROUKLIS ; K. STROESSNER
P.P.I. - F.K.F.
H e i s e n b e r s t r . 1 D - 7000 STUTTGART 80
U n i v e r s i t B P. e t M. Curie 4, Place Jussieu
75230 P a r i s Cedex 05 SCHLOESSIN H.
Dept. o f Geophysics Univ. o f Western O n t a r i o LONDON ONTARIO
N6A 587 CANADA SHERMAN W.
Dept. o f Physics K i n g ' s College Strand
LONDON WC2 R 2LS GRANDE BRETAGNE VOLLSTAEDT H.
Z e n t r a l i n s t i t u t f u r Physik der Erde 1500 POTSDAM
Telegrafenberg DDR
