Low-field colossal magnetoresistance in bandwidth-controlled manganites

被引：19

作者：

Kuwahara, H ^{[1
]}

Moritomo, Y ^{[1
]}

Tomioka, Y ^{[1
]}

Asamitsu, A ^{[1
]}

Kasai, M ^{[1
]}

Tokura, Y ^{[1
]}

机构：

[1] UNIV TOKYO,DEPT APPL PHYS,TOKYO 113,JAPAN

来源：

JOURNAL OF APPLIED PHYSICS | 1997年 / 81卷 / 08期

关键词：

D O I：

10.1063/1.364707

中图分类号：

O59 [应用物理学];

学科分类号：

摘要：

We have investigated magnetoresistance (MR) phenomena relevant to the charge ordering (CO), namely, the real space ordering of both Mn3+ and Mn4+, in single crystals of (Nd1-ySmy)(1/2)Sr1/2MnO3, in which the one-electron bandwidth (W) is systematically controlled by varying the average ionic radius of the A site. The low-field colossal MR is observed for the small-W region of y greater than or equal to 0.5; e.g., rho(0)/rho(H) > 10(3) in a field of 0.3 T at 115 K for the y = 0.94 crystal. This is viewed as a first-order insulator-to-metal phase transition induced by a magnetic field, which accompanies a lattice-structural change. In the small-W region, the CO instability accompanying the antiferromagnetic spin correlations subsists even above the ferromagnetic transition temperature T-c. The competition between the ferromagnetic double-exchange and antiferromagnetic CO interactions gives rise to such a lattice-coupled first-order phase transition induced by a relatively low magnetic field. (C) 1997 American Institute of Physics.

引用

页码：4954 / 4956

页数：3

共 17 条

[1] LATTICE EFFECTS ON THE MAGNETORESISTANCE IN DOPED LAMNO3 [J].