Study on magnetism of Pr_(0.45)(Ca_(1-x)Sr_x)_(0.55) MnO_3 samples  

作　　者：TANG Yonggang WANG Guiying YANG Gang MAO Qiang PENG Zhensheng 

机构地区：[1]Cultivating Base of Anhui Key Laboratory of Spintronics and Nano-materials Research, Suzhou 234000, China [2]Department of Electrical and Electromc Engmeertng, Suzhou University, Suzhou 234000, China [3]Hefei National Laboratory for Microscopic Matter Sciences, University of Science and Technology of China, Hefei 230026, China

出　　处：《Rare Metals》2011年第6期595-601,共7页稀有金属（英文版）

基　　金：financially supported by the National Natural Foundation of China (Grant No.19934003);the Natural Science Research Key Program of Anhui Educational Committee (KJ2011A259);the Cultivating Base of Anhui Key Laboratory of Spintronics and Nano-materials Research Program(No.2010YKF04)

摘　　要：The polycrystalline samples of Pro.45（Ca1-xSrx）0.55MnO3 （x = 0.0, 0.2, 0.4, 0.6） were prepared by solid-state reaction. Influence of Sr2＋ substitution for Ca2＋ at A site on magnetism was studied through the measurements of X-ray diffraction （XRD） spectrum, the magnetization-temperature （M-T） curves and electron spin resonance （ESR） curves. The results show that the magnetism strengthens and charge ordering weakens gradually with the increase of Sr2＋ substitution amount, respectively. The transition of paramagnetism（PM）-antiferromagnetism（AFM） occurs below the transition temperature of charge ordering （Tco）, and there is tittle ferromagnetic phase in the antiferromagnetic background at the lower temperature, which results in complex magnetic phases of the samples. Ferromagnetic clusters appear and grow larger with the increase of substitution amount./n addition, the reentrant spin-glass behavior appears at about 41 K. The magnetism phenomenon of the samples is mainly due to the competition between double exchange and Jahn-Teller coupling. The Jahn-Teller coupling becomes weak, and the double exchange wins the advantage in the competition with the increase of substitution amount, which leads to the magnetism variation of the system.The polycrystalline samples of Pro.45（Ca1-xSrx）0.55MnO3 （x = 0.0, 0.2, 0.4, 0.6） were prepared by solid-state reaction. Influence of Sr2＋ substitution for Ca2＋ at A site on magnetism was studied through the measurements of X-ray diffraction （XRD） spectrum, the magnetization-temperature （M-T） curves and electron spin resonance （ESR） curves. The results show that the magnetism strengthens and charge ordering weakens gradually with the increase of Sr2＋ substitution amount, respectively. The transition of paramagnetism（PM）-antiferromagnetism（AFM） occurs below the transition temperature of charge ordering （Tco）, and there is tittle ferromagnetic phase in the antiferromagnetic background at the lower temperature, which results in complex magnetic phases of the samples. Ferromagnetic clusters appear and grow larger with the increase of substitution amount./n addition, the reentrant spin-glass behavior appears at about 41 K. The magnetism phenomenon of the samples is mainly due to the competition between double exchange and Jahn-Teller coupling. The Jahn-Teller coupling becomes weak, and the double exchange wins the advantage in the competition with the increase of substitution amount, which leads to the magnetism variation of the system.

关 键 词：MAGNETISM charge ordering Sr2＋ substitution reentrant spin-glass state 

分 类 号：O484.1[理学—固体物理] TM27[理学—物理]