La_2/3(Ca_0.6Ba_0.4)MnO₃中的磁热效应研究  

Magnetocaloric Effect in La2/3(Ca0.6Ba0.4)MnO3

作　　者：侯薇薇 张旎 叶晴莹 陈水源 韩森 王可 黄志高 Weiwei Hou;Ni Zhang;Qingying Ye;Shuiyuan Chen*;Sen Han;Ke Wang;Zhigao Huang(Fujian Provincial Key Laboratory of Quantum Manipulation and New Energy Materials, College of Physics and Energy, Fujian Normal University, Fuzhou Fujian)

机构地区：[1]福建师范大学物理与能源学院,福建省量子调控与新能源材料重点实验室,福建福州

出　　处：《应用物理》2017年第2期37-42,共6页Applied Physics

基　　金：国家自然科学基金(11004031);福建省自然科学基金(2016J01007);福建省新世纪优秀人才计划(JA12054);福建省教育厅重点项目(JA15100)的资助。

摘　　要：采用溶胶–凝胶法制备了La2/3(Ca0.6Ba0.4)MnO3 (简写为LCBMO)靶材,并通过及脉冲激光沉积法(PLD)在石英衬底上制备LCBMO薄膜。研究了块体和薄膜结构LCBMO的结构、磁性和磁热效应。实验结果表明,通过PLD方法可以得到纯相结构的LCBMO 薄膜;温度特性测试表明薄膜结构的LCBMO,其居里温度(260.2 K)比块体材料下降30 K;此外,我们得到了LCBMO体系的磁熵变特性。在外磁场2T、居里温度(TC)附近,块体LCBMO的磁熵变(ΔSM)达到最大值2.1 J/kg?K;而LCBMO薄膜的ΔSM也在TC附近达到最大值(8.4 mJ/cm3?K),且在TC附近较宽的温区范围内,ΔSM值均较大,表明这一薄膜体系在宽温区磁制冷工质方面有潜在的应用。La2/3(Ca0.6Ba0.4)MnO3 (named as LCBMO) target was prepared by sol-gel method. LCBMO thin film was deposited onto SiO2 substrate by pulsed laser deposition (PLD) technique. The crystal structure, magnetic properties and magnetocaloric effect were investigated. The experimental results indicate that, pure phase LCBMO thin film can be obtained by PLD technique. M-T measurement results show the Curie temperature (TC) of LCBMO thin film (260.2 K) is lower than that of bulk LCBMO (299.9 K). Moreover, magnetic entropy properties were obtained in LCBMO systems. The maximum values of magnetic entropy change (ΔSM, 2.1 J/kg?K for bulk LCBMO and 8.4 mJ/cm3?K for LCBMO thin film) were obtained near TC with H = 2T. Besides, the value of ΔSM is relative large in a wide temperature region near TC, which indicates that the thin film possesses potential application in wide-temperature-range magnetic refrigeration.

关 键 词：钙钛矿锰氧化物 磁热效应 磁熵变 

分 类 号：O48[理学—固体物理]