钙钛矿锰氧化物(La_(1-x)Gd_x)_(0.5)Sr_(0.5)MnO_3的电磁特性  

Electronic and Magnetic Properties of Perovskite Manganities(La_(1-x)Gd_x)_(0.5)Sr_(0.5)MnO_3

作　　者：周敏[1] 郑琳[2] 赵建军[2] 吴鸿业[2] 鲁毅[2] 

机构地区：[1]内蒙古科技大学数理与生物工程学院,内蒙古包头014010 [2]包头师范学院物理系,内蒙古包头014030

出　　处：《稀土》2010年第5期24-27,共4页Chinese Rare Earths

基　　金：国家自然科学基金项目资助(50862007);内蒙古自治区科学基金项目资助(2009MS0101)

摘　　要：通过磁化强度和电阻的测量对多晶样品(La1-xGdx)0.5Sr0.5MnO3(x=0,0.1,0.2,0.3,0.4)的电磁特性进行了系统的实验研究。当x≤0.2时,样品显示出铁磁金属态(FMM)到顺磁绝缘态(PM I)的转变;当0.3≤x≤0.4时,金属-绝缘体转变温度Tp消失,样品显示出反铁磁绝缘态(AFM I)到顺磁绝缘态(PM I)的转变。同时随着x的增加所有样品的居里温度Tc和金属-绝缘体转变温度Tp都降低,并且在居里温度附近观测到了磁电阻效应。Electronic and magnetic properties of polycrystalline samples（La1-xGdx）0.5Sr0.5MnO3（x=0,0.1,0.2,0.3,0.4）were systematically studied by the measurements of magnetization and resistance.When x≤0.2,samples exhibit a transition from a ferromagnetic metal state（FMM） to a paramagnetic insulator state（PMI）;The metal-insulator transition temperature is disappear,the antiferromagnetic insulator（AFMI）-paramagnetic insulator（PMI） transition shows up in the compositions for 0.3≤x≤0.4.Meanwhile,for all samples,both the curies temperature Tc and the metal-insulator transition temperature decrease with increasing Gd content,and MR effect near Tc can be observed.

关 键 词：锰氧化物 电性 磁性 

分 类 号：O482.52[理学—固体物理] O614.33[理学—物理]