钙钛矿锰氧化物(La_(1-x)Gd_x)_(0.5)Sr_(0.5)MnO_3的磁电阻效应  

Magneto-Resistance Effect of Perovskite Manganites(La_(1-x)Gd_x)_(0.5)Sr_(0.5)MnO_3

作　　者：鲁毅[1] 周敏[2] 郑琳[1] 邢茹[1] 赵建军[1] 吴鸿业[1] 

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

出　　处：《中国稀土学报》2010年第5期582-585,共4页Journal of the Chinese Society of Rare Earths

基　　金：国家自然科学基金项目(50862007);内蒙古自治区科学基金项目(2009MS0101);内蒙古自治区高等学校科学研究项目(NJ10163);包头师范学院科研创新团队资助

摘　　要：采用传统的高温固相法制备了多晶样品(La1-xGdx)0.5Sr0.5MnO3(x=0,0.1,0.2,0.3,0.4),利用X射线衍射仪(XRD)、超导量子磁强计(SQUID)、标准四端引线法分别对样品结构、磁性、电性以及磁电阻效应进行了研究。研究表明:Gd的少量替代并没有引起结构变化;随着Gd含量的增加,所有样品的居里温度TC和金属-绝缘体转变温度Tp都降低了;在TC附近发现了磁电阻效应,同时在低温下发现了更大的磁电阻;并且Gd的少量替代可使磁电阻MR增大。The polycrystalline samples（La1-xGdx）0.5Sr0.5MnO3（x=0,0.1,0.2,0.3,0.4） were prepared by traditional high temperature solid state reaction.The structure,magnetic properties,electric properties and magneto-resistance were characterized by X-ray diffraction（XRD）,superconductor quantum interference device（SQUID） and standard four-probe method.The results showed that the substitution of a little Gd on La site did not change the structure.For all samples,both the Curie temperature TC and the metal-insulator transition temperature Tp decreased with increasing Gd content.The MR effect near TC and more MR signals in the low temperature could be observed.And the magneto-resistance could be increased with the substitution of a little Gd for La.

关 键 词：锰氧化物 磁性 电性 磁电阻 稀土 

分 类 号：O482.52[理学—固体物理] O614.33[理学—物理]