The effect of annealing process on the physical properties of La1-xNaxMnOy

被引：9

作者：

Ahmed, M. ^{[1
]}

Saleh, S. A. ^{[1
]}

Ibrahim, E. M. M. ^{[1
]}

Bontempi, E. ^{[2
]}

Mohamed, H. F. ^{[1
]}

机构：

[1] Sohag Univ, Dept Phys, Sohag 82524, Egypt

[2] Univ Brescia, INSTM, Dipartimento Ingn Meccan, Lab Strutturist Chim, I-25123 Brescia, Italy

来源：

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS | 2008年 / 320卷 / 06期

关键词：

magnetoresistance; transport property; annealing time;

D O I：

10.1016/j.jmmm.2007.08.031

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

The effect of Na doping and annealing time on the structure, electrical properties, magnetoresistance and thermopower properties has been investigated in perovskite La1-xNaxMnOy (x = 0.025, 0.075 and 0.1) systems. La1-xNaxMnOy crystallizes in a single-phase rhombohedral structure. It is observed a simultaneous occurrence of the ferromagnetic to paramagnetic state and metallic to insulating state. In the meanwhile, a large negative magnetoresistance with low applied magnetic field is observed. In addition, rho(T) curves for Na-doped samples exhibit another broad transition T-ms2 below T-ms. Such double peak behavior in the rho(T) curve interpreted by the electronic inhomogeneity in the samples. The sign of S changes from positive to negative depending on composition. The values of Seebeck coefficient are small (in the microvolt range). (C) 2007 Elsevier B.V. All rights reserved.

引用

页码：L43 / L49

页数：7

共 33 条

[1] Crystal structure and some transport properties of Na-doped LaMnOy [J].