相分离锰氧化物中的电流振荡和低场巨磁阻效应
强关联电子
2009-11-11 v1 材料科学
摘要
在(La_{1-y}Pr_y)_{0.7}Ca_{0.3}MnO_3 (y=0.7)和Nd_{0.5}Ca_{0.5}Mn_{1-z}Cr_zO_3 (z=0.03)晶体的相分离态中观察到电流诱导的从金属态到绝缘态的切换。对此电流诱导的绝缘态施加磁场会导致显著的低场负磁阻效应[r(H)/r(0)=10^{-3} at H=1kOe]。施加恒定电压也会导致在阈值电压以上欧姆关系的破坏。在高于此阈值的电压下，观察到电流振荡。该振荡可以通过渗流导电路径的局部切换的简单模型很好地再现。
引用
@article{arxiv.cond-mat/0504128,
title = {Current oscillation and low-field colossal magnetoresistance effect in phase-separated manganites},
author = {M. Tokunaga and H. Song and Y. Tokunaga and T. Tamegai},
journal= {arXiv preprint arXiv:cond-mat/0504128},
year = {2009}
}
备注
5 pages, 4 figures, to be published in Physical Review Letters