强关联锰氧化物Sm_(0.5)Ca_(0.5)Mn_(1-x)Ga_xO_3的结构及磁基态研究  

Study on Structure and Magnetic Ground State in Strongly Correlated Manganites Sm_(0.5)Ca_(0.5)Mn_(1-x)Ga_xO_3

作　　者：荆振南 李玉[1] Jing Zhennan;Li Yu(Northeast Forestry Universit)

机构地区：[1]东北林业大学

出　　处：《哈尔滨师范大学自然科学学报》2018年第1期76-80,84,共6页Natural Science Journal of Harbin Normal University

基　　金：中央高校基础科研业务费(2572015DY04);黑龙江省自然科学基金(留学回国人员科学基金)(LC2015003);黑龙江省自然科学基金(E201404)

摘　　要：采用高温固相法合成Sm_(0.5)Ca_(0.5)Mn_(1-x)Ga_xO_3(x=0、0.025、0.05、0.75、0.10、0.15)单相多晶系列样品.室温XRD分析表明样品无杂峰,属于典型的O型正交结构;红外吸收光谱分析发现Ga的掺杂导致样品的MnO_6八面体结构发生了微小畸变;x=0样品热磁曲线(M-T)分析表明样品在低温下表现出自旋玻璃态,在T=276 K时出现电荷有序峰,在T=240 K出现AFM相变温度峰,当T=140 K时发现冻结温度T_f;磁化曲线(M-H)结果进一步证明2 K下样品自旋玻璃态,且电荷有序反铁磁成分中的关联作用比较弱.The single phase polycrystalline samples,Sm0.5Ca0.5Mn1-xGaxO3（ x = 0,0. 025,0. 05,0. 075,0. 10,0. 15） are synthesized by high temperature solid-state reaction. The study of these samples by XRD at room temperature shows that they are belong to a typical sample structure which are the orthorhombic O type structure,and the analysis of the infrared absorption spectrum indicates that these structures of the samples have faintly distorted by Ga doping. For the sample of x = 0,the analysis from the measurements of magnetization-temperature（ M-T） curves shows that the sample is a spin glass ground state at low temperature,the charge ordering peak appears at T = 276 K,and there is a peak which denotes the temperature of AFM phase transition when the temperature is 240 K,the freezing temperature Tf appears at T = 140 K. The result of magnetization curves（ M-H） further illustrates the phenomenon that the sample of x = 0 is under the spin glass ground state when T = 2 K.

关 键 词：钙钛矿型锰氧化物 电荷有序 自旋玻璃 

分 类 号：O469[理学—凝聚态物理]