Proton spin-lattice relaxation study of the neutral-to-ionic transition in TTF-chloranil

The temperature dependence of the critical stress and strain required to induce mechanically one phase from the other, allows the Landau parameters of the transition to

amplitude modes in the biaxial phase mix the components of biaxiality and birefringence of the order parameter, the critical (quasi-biaxial) mode presenting

2014 We present an ultrasonic investigation of the nematic-isotropic phase transition in p-azoxyanisole (PAA). Our measurements were performed at several frequencies

of the RKKY spin-glass and shown that the non-exponential relaxation persists far above the transition point, in fact it persists up to the maximum transition

- From the study of pyroelectric coefficient p* during constant-rate-temperature- increase (0,03-1,s OC.s-1) its thickness dependence was found (for the thickness

these cubic phases : a fast uniaxial rotation of the molecule around its C-CmN axis and a slow tumbling reorientation of this axis among the (001) directions by instantaneous jumps6.

This anomalous behavior is characteristic of a soft optic mode inducing a phase transition and is similar to the results observed by Sapriel et a1.l The emergence of an

Consequence of this change was the adoption of an atomic timescale as the world time reference; relevant international or- ganizations and scientific unions working together