Anomalous high pressure dependence of the Jahn-Teller phonon in La0.75Ca0.25MnO3

被引：90

作者：

Congeduti, A

Postorino, P

Caramagno, E

Nardone, M

Kumar, A

Sarma, DD

机构：

[1] Univ Rome La Sapienza, Dipartimento Fis, Ist Nazl Fis Mat, Unita, I-00185 Rome, Italy

[2] Univ Roma Tre, Dipartimento Fis, Unita, Ist Nazl Fis Mat, I-00146 Rome, Italy

[3] Indian Inst Sci, Solid State & Struct Chem Unit, Bangalore 560012, Karnataka, India

来源：

PHYSICAL REVIEW LETTERS | 2001年 / 86卷 / 07期

关键词：

D O I：

10.1103/PhysRevLett.86.1251

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

Raman spectra of La0.75Ca0.25MnO3 have been collected for the first time over a wide pressure range (0-14 GPa) using a diamond anvil cell. The frequency range explored (200-1100 cm(-1)) and the very good quality of the data allowed us to carefully analyze the pressure evolution of the phonon modes of the MnO6 octahedra. The results show an abrupt transition at similar to7.5 GPa with an evident deviation from the linear trend of the frequency of the Jahn-Teller phonon versus the applied pressure, accompanied by a strong phonon broadening. This behavior disagrees with the predicted insulator to metal transition and, on the contrary, indicates the occurrence of a new unpredicted phase in the very high pressure regime.

引用

页码：1251 / 1254

页数：4

共 30 条

[1] Infrared studies of a La0.67Ca0.33MnO3 single crystal:: Optical magnetoconductivity in a half-metallic ferromagnet [J].