Japanese Journal of Applied Physics, vol.32, no.S3, pp.766-767, 1993 (Scopus)
Possibility of the phase transition accompanied by the modes, different from the well-known soft mode observed in majority of crystals, is pointed out. An evidence for existence of such a mode is also given on the basis of studying thetemperature behaviour of quadrupole perturbed nuclear magnetic resonance frequency of gallium nuclei. © 1993 The Japan Society of Applied Physics.