摘要
本工作制备了La065(Ca,Ba)035Mn1-xFexOy(x=0～02)氧化物系列样品。发现在常温附近,含Ba样品的磁阻变化率远比相应含Ca样品的高。在x=0时,样品电阻随温度的变化曲线存在金属—半导体转换峰,随着Fe对Mn的部分替代,该转换峰向低温区移动,当替代量x达到一定程度时,在实验温区观察不到金属—半导体转换峰。磁阻效应在高铁含量时只能在低温观察到。Fe替代Mn对大磁阻效应的影响,可能主要因为:随着Mn3+被Fe3+所替代,样品La065(Ca,Ba)035Mn1-xFexOy中的铁磁相互作用受到抑制,反铁磁相互作用得到加强。
In the present work,the compounds La 0.65 (Ca,Ba) 0.35 Mn 1-x Fe xO y (x=0～0.2) have been prepared.We measured the resistance under both the magnetic field and zero field.Results show that near room temperature,the magnetoresistance ratio is larger for samples with Ba than with Ca.For the sample with x=0,there is a transforming peak from conducting to semiconducting in the dependence of resistance on the temperature.With increasing Fe content,this transforming peak moves to the low temperature range.At a certain Fe content,such transforming peak can not be observed.The magnetoresistance effect can be observed at low temperature for samples with higher Fe content.With replacement of Mn by Fe,the ferromagnetic interaction in La 0.65 (Ca,Ba) 0.35 Mn 1-x Fe xO y compounds may be suppressed,whereas the antiferromagnetic interaction may be enhanced.
出处
《稀土》
EI
CAS
CSCD
北大核心
2000年第1期19-22,共4页
Chinese Rare Earths
基金
国家自然科学基金!项目 (编号 :5 9772 0 40 )
国家重点基础研究项目
