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STUDIES ON THE BEHAVIOR OF THE INTERNAL VIBRATIONAL MODES IN (NH4)2TexSn1-xCl6 MIXED CRYSTALS
ZHANG JIA-MING (张家明), SHEN XUE-CHU (沈学础), ZHOU TAO (周涛), XIE YUE-BAO (谢韵宝), XU YONG-CHEN (徐永晨), SHEN JUN (沈军), ZHOU PEI-ZHEN (周佩珍), J.PELZL
Acta Physica Sinica (Overseas Edition), 1993, 2 (3):
206-212.
DOI: 10.1088/1004-423X/2/3/006
The behavior of the internal lattice vibrational modes in (NH4)2TexSn1-xCl6 mixed crystals has been investigated by Raman scattering. All of the Raman-active [MX6]2- internal modes show two-mode property in the mixed crystals with compositions from x=0 to 1, and apart from the sample with x=0.5, their energy positions are composition-independent. Space group calculations including site symmetry considerations and frequency fittings describe a good force field model. It has been demonstrated that the composition-independent two-mode behavior may come from the strong clustering effect, rather than from the character of the gap and local modes of impurities in mixed crystals. For the sample with x=0.5, the two component elements seem to form a pseudo-periodic lattice structure.
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