Phase transition in C 2O 4DND 4, ${\bf 1}/{\bf 2}$D 2O : a coherent inelastic neutron scattering study

The results of this work will be discussed together with ultrasonic spectroscopy (US) data available in literature [6-9], reporting values of the sound speed in the

Inelastic scattering of neutrons has revealed soft optic modes at the T point (b* + c* ) of the Brillouin zone both in Rb~ZnC14 and K2ZnC14 which are responsible for the 22.

is the nature of the structural phase transition taking place at about 260 K This transition has been detected [I] recently by differential scanning calorimetry (DSC), and

= 6, one can evaluate trie cyclotron mass from trie temperature dependence of trie amplitude of trie oscillations. Trie thermal factor is expected to be xl

These modes could no longer be resolved in the SmB phase. - a) Schematic representation of the molecular motions for the shear mode propagating in the c* direction with a

The data (two runs) belowlabove To are specified by full/open symbols. In X-ray single crystal experiments we have studied the influence of domains in the distor- ded low

In the last part of this section we shall discuss the classical notion of relaxation time and show that below a phase transition, various contributions.. modify

To draw the (P, T) phase diagram we have therefore observed the linewidth behaviour of this mode on one hand under constant pressure and variable temperature, on the