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Physical Properties of K 2 ZnCl 4
Author(s) -
Jeong S. Y.,
Jang M. S.,
Han S. K.,
Haussühl S.
Publication year - 1992
Publication title -
crystal research and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.377
H-Index - 64
eISSN - 1521-4079
pISSN - 0232-1300
DOI - 10.1002/crat.2170270627
Subject(s) - orthorhombic crystal system , anisotropy , ferroelectricity , dielectric , hysteresis , materials science , condensed matter physics , thermal hysteresis , analytical chemistry (journal) , crystallography , chemistry , optics , crystal structure , optoelectronics , phase transition , physics , chromatography
Abstract Large single crystals of orthorhombic K 2 ZnCl 4 with optical quality have been grown by the Czochralski method. The elastic constants and their temperature and pressure derivatives have been determined from ultrasonic resonance frequencies of thick plates of different orientation and the shift of these frequencies induced by temperature and pressure changes, respectively. K 2 ZnCl 4 shows a small elastic anisotropy. Measurement of the dielectric constant was made along the ferroelectric axis ε a in the temperature from 303 K to 573 K. ε a of K 2 ZnCI 4 grown by the Czochralski‐method shows a smaller thermal hysteresis at the incommensurate‐commensurate transition point (403 K) than that of crystals grown from an aqueous solution. It explains that crystals grown by the Czochralski‐method are more purified, the pinning effect is weakened. The thermal hysteresis occurs with the same width at 10 KHz, 100KHz, 1 MHz and 10 MHz.