POLARIZED RAMAN-SCATTERING FROM ORTHORHOMBIC AND TETRAGONAL GDBA2CU3O7-DELTA SINGLE-CRYSTALS - NEW EVIDENCE OF CHAINS-TO-PLANES CHARGE REDISTRIBUTION

被引：11

作者：

HADJIEV, VG

ILIEV, MN

RAPTIS, C

KALEV, L

WANKLYN, BM

机构：

[1] NATL TECH UNIV ATHENS,DEPT PHYS,GR-15773 ATHENS,GREECE

[2] UNIV OXFORD,CLARENDON LAB,OXFORD OX1 3PU,ENGLAND

来源：

PHYSICA C | 1990年 / 166卷 / 3-4期

关键词：

D O I：

10.1016/0921-4534(90)90399-Y

中图分类号：

O59 [应用物理学];

学科分类号：

摘要：

Raman scattering spectra of various polarisation configurations have been obtained from as-grown single crystals of Gd-Ba2Cu3O7-δ in both the orthorhombic (δ≈0.1) and tetragonal (0.7<δ<0.9) phases using the microprobe technique. Apart from the five Ag phonons at 118, 149, 331, 433 and 506 cm-1, two more Raman lines at 205 and 302 cm-1 have been observed in cross-polarisation spectra of the orthorhombic phase exhibiting B2g and B3g symmetries respectively. There was no observation of respective nondiagonal Eg symmetry modes in the tetragonal phase. The changes in the lineshapes and intensities for the same scattering configurations of the orthorhombic and tetragonal phases provide evidence for a strong influence of the free carriers on the scattering process. The experimental results are compatible with the concept of chains-to-planes charge transfer. © 1990.

引用

页码：225 / 230

页数：6