Lattice Effects and Irreversible Magnetoresistance in Gd Doped La-Ca-Mn-O  

作　　者：Baoxin HUANG, Yihua LIU, Ruzhen ZHANG, Chengjian WANG, Gang JI and Liangmo MEIDepartment of Physics and State Key Laboratory of Crystal Materials, Shandong University, Jinan, 250100, China 

出　　处：《Journal of Materials Science & Technology》2002年第6期509-512,共4页材料科学技术（英文版）

基　　金：This work was supported by the State Key Project of Funda-mental Research (G19980613010) ; the National Scientific and Technological Department of China.

摘　　要：The Gd substituting effects for La in La0.67Ca0.33MnO3 has been studied. With increasing the substituting amount of Gd, the phase transition temperature of metal-isolator for the samples decreases, the corresponding peak resistivity increases, the Curie temperature decreases monotonically. The substitution of La-Ca-Mn-O with 11% Gd for La improved the magnetoresistance ratio by an order of magnitude. The effects of substituting Gd can be explained in terms of the lattice effects. An irreversible MR behaviour was observed in Gd-substituting compounds. This effect became marked when the substituting amount of Gd was greater than 7%. A maximum irreversible increment of MR ratio as large as 91% was obtained when Gd substituting amount was 11%.The Gd substituting effects for La in La0.67Ca0.33MnO3 has been studied. With increasing the substituting amount of Gd, the phase transition temperature of metal-isolator for the samples decreases, the corresponding peak resistivity increases, the Curie temperature decreases monotonically. The substitution of La-Ca-Mn-O with 11% Gd for La improved the magnetoresistance ratio by an order of magnitude. The effects of substituting Gd can be explained in terms of the lattice effects. An irreversible MR behaviour was observed in Gd-substituting compounds. This effect became marked when the substituting amount of Gd was greater than 7%. A maximum irreversible increment of MR ratio as large as 91% was obtained when Gd substituting amount was 11%.

关 键 词：Manganese perovskites Colossal magnetoresistance Lattice effect Irreversible magnetoresistance 

分 类 号：TG111[金属学及工艺—物理冶金]