ANOMALOUS BEHAVIOR OF THE TRANSVERSE ACOUSTIC PHONONS IN KTA1-XNBXO3

被引：11

作者：

FONTANA, MD

KUGEL, GE

FOUSSADIER, L

KRESS, W

RYTZ, D

机构：

[1] MAX PLANCK INST, W-7000 STUTTGART 80, GERMANY

[2] SANDOZ SA, CTR RECH & OPTOELECTR, F-68330 HUNINGUE, FRANCE

来源：

EUROPHYSICS LETTERS | 1993年 / 23卷 / 06期

关键词：

PHONON STATES AND BANDS; NORMAL MODES; AND PHONON DISPERSION; FERROELECTRICITY AND ANTIFERROELECTRICITY; PHONONS AND VIBRATIONS IN CRYSTAL LATTICES;

D O I：

10.1209/0295-5075/23/6/008

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

In addition to the already known softening of the lowest transverse optic mode (TO) in KTa1-xNbxO3 a pronounced temperature dependence of the transverse acoustic (TA) mode in the [100] direction of the Brillouin zone has been observed by inelastic-neutron-scattering measurements for Nb concentrations of x = 0.008 and 0.012. In the vicinity of the phase transition the dispersion curve of the TA branch exhibits peculiarities at small wave vectors. The observed anomalies are attributed to hybridization effects of modes belonging to the same representation and to an exchange of eigenvectors between TO and TA modes.

引用

页码：427 / 432

页数：6

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