This article is cited in 6 papers

Optical properties

Investigation of the ferroelastic phase transition in the SrMgF$_4$ pyroelectric crystal

S. V. Melnikova^a, L. I. Isaenko^b, A. A. Goloshumova^b, S. I. Lobanov<sup>b

a</sup> L. V. Kirensky Institute of Physics, Siberian Branch of the Russian Academy of Sciences, Krasnoyarsk
^b Sobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, Novosibirsk

Abstract: A SrMgF$_4$ compound has been synthesized and a high optical-quality crystal has been grown. Optical-polarization observations, X-ray diffraction analysis, and the measurement of the birefringence $\Delta n_i(t)$ in the SrMgFF$_4$ crystal have been carried out in the temperature range of 90–1200 K. A second-order improper ferroelastic phase transition accompanied by birefringence anomalies and the symmetry change $P$112$_1$ ($Z$ = 12) $\leftrightarrow Cmc2_1$ ($Z$ = 4) has been discovered at $T_0$ = 478 $\pm$ 1 K. The crystal remains pyroelectric in both phases. Considerable contributions of the fluctuations of the order parameter have been observed in the temperature ranges of $(T_0-T)<$ 15 K and $(T-T_0)<$ 60 K.

Received: 13.06.2013
Accepted: 12.09.2013

 English version: Physics of the Solid State, 2014, 56:4, 757–760

Bibliographic databases:

•