Magnetic-Field-Induced Metal-Insulator Transition in Pr0.7Ca0.3MnO3
Magnetic-Field-Induced Metal-Insulator Transition in Pr0.7Ca0.3MnO3
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DOI：
10.1143/jpsj.65.1043
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发表时间：
1996-04
影响因子：
1.7
通讯作者：
H. Yoshizawa;H. Kawano;Y. Tomioka;Y. Tokura
中科院分区：
文献类型：
--
作者：
H. Yoshizawa;H. Kawano;Y. Tomioka;Y. Tokura
用中子衍射实验研究了Pr 0.7Ca0.3MnO3晶体的场致绝缘体-金属（I-M）相变。在整个温度范围内，Pr 0.7Ca0.3MnO3的电阻率在零电场下表现为绝缘行为，但在5 K下约4.0T处出现I-M转变。它已被确定，施加的字段强制执行铁磁自旋排列和驱动Pr0.7Ca0.3MnO3的金属状态，通过启动双交换机制和破坏的电荷有序。在5 K下的I-M转变伴随着大的滞后。相比之下，在50 K的场依赖性，反铁磁和电荷序分量逐渐恢复低于2.0 T的场下降的过程。此外，在2.5T的温度依赖性中观察到了重入I-M-I跃迁。
A field-induced insulator-metal (I-M) transition in Pr 0.7 Ca 0.3 MnO 3 has been studied with neutron diffraction experiments. Over the whole temperature range, the resistivity of Pr 0.7 Ca 0.3 MnO 3 shows insulating behavior at zero field, but exhibits an I-M transition at around 4.0 T at 5 K. It has been established that an applied field enforces a ferromagnetic spin alignment and drives Pr 0.7 Ca 0.3 MnO 3 to a metallic state by actuating the double exchange mechanism and destroying the charge ordering. This I-M transition at 5 K is accompanied with a large hysteresis. By contrast, in the field dependence at 50 K, antiferromagnetic and charge-order components are gradually recovered below 2.0 T in a field-decreasing process. Furthermore, a reentrant I-M-I transition has been observed in the temperature dependence at 2.5 T.