Temperature Dependence of Phonon Modes in Nanocrystalline La0.67Ca0.33MnO3 as Observed by Infrared Spectroscopy

被引：1

作者：

Sairam, T. N. ^{[1
]}

Dey, P. ^{[2
]}

Mangamma, G. ^{[1
]}

Nath, T. K. ^{[2
]}

Sundar, C. S. ^{[1
]}

机构：

[1] Indira Gandhi Ctr Atom Res, Div Mat Sci, Kalpakkam 603102, Tamil Nadu, India

[2] Indian Inst Technol, Dept Phys & Meteorol, Kharagpur 721302, W Bengal, India

来源：

JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY | 2009年 / 9卷 / 09期

关键词：

Manganites; Nanoparticles; Infrared Spectroscopy; Phonons; Polarons; FERROMAGNETIC TRANSITION-TEMPERATURE; MANGANESE OXIDE LA0.67CA0.33MNO3; GIANT MAGNETORESISTANCE; LA0.7CA0.3MNO3; MANGANITES; PEROVSKITES; PARTICLE; SIZE;

D O I：

10.1166/jnn.2009.1167

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

Low temperature infrared absorption measurements have been carried out on nanocrystalline La0.67Ca0.33MnO3 powder across the magnetic and the insulator-to-metal phase transitions. Interesting changes are observed in the temperature dependence of the mid-IR polaronic background and the stretching mode of the MnO6 octahedron. Upon cooling below 250 K, the overall absorbance increases, but, unlike in the case of microcrystalline LCMO, the stretching mode is not completely screened even at 5 K. The temperature dependence of the stretching mode parameters points to a much reduced phonon-polaron coupling as compared to that in the bulk material.

引用

页码：5471 / 5475

页数：5

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