Low Temperature Physics: 30, 912 (2004); https://doi.org/10.1063/1.1820023 (4 pages)
Fizika Nizkikh Temperatur: Volume 30, Number 11 (November 2004), p. 1214-1218    ( to contents , go back )

Ultrasonic investigation of phase transitions in ZnSe:Ni

V.V. Gudkov1, A.T. Lonchakov2, I.V. Zhevstovskikh2, V.I. Sokolov2, N.B. Gruzdev2, and S.B. Petrov1

1The state professional - pedagogical university Street. Machine engineers, 11, Ekaterinburg, 620012, Russia
E-mail: gudkov@imp.uran.ru

2Institute of Metal Physics , S. Kovalevskoyi st. 18, Ekaterinburg 620219, Russia
pos Анотація:

Received June 1, 2004

Abstract

The ultrasonic experiments on ZnSe and ZnSe:Ni crystals with an impurity concentration of 5,5·1019 cm–3 revealed precursor phenomena at temperatures much higher the transition point (Tc = 14.5 K). It is found that the elastic modulus C44 becomes softer and the moduli C11 and C12 become harder with approaching Tc from higher temperatures; the deformations associated with the order parameter are transverse deformations of e4 type. A brief symmetry analysis of possible formations of the tetragonal phase is given. The Jahn—Teller effect and the chemical bond shift of charge density are discussed as possible reasons of the low temperature phase transition.

PACS:
61.72.Vv - Doping and impurity implantation in III-V and II-VI semiconductors
43.35.+d - Ultrasonics, quantum acoustics, and physical effects of sound
64.70.Kb - Solid-solid transitions (see also 61.50.Ks Crystallographic aspects of phase transformations; pressure effects; 75.30.Kz and 77.80.Bh for magnetic and ferroelectric transitions, respectively; for material science aspects, see 81.30.-t)

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