Si掺杂Pr_(0.5)Sr_(0.5)MnO_(3)体系的磁性和磁热性能研究  

Study on the magnetic properties and magnetocaloric effect of the Si-doped Pr_(0.5)Sr_(0.5)MnO_(3)system

作　　者：方杰扬 杨杭福 FANG Jieyang;YANG Hangfu(College of Materials and Chemistry,China Jiliang University,Hangzhou 310018,China)

机构地区：[1]中国计量大学材料与化学学院,浙江杭州310018

出　　处：《中国计量大学学报》2022年第3期366-372,共7页Journal of China University of Metrology

基　　金：国家自然科学基金项目(No.11904343);浙江省自然科学基金项目(No.LY21A040006);浙江省重点研发计划项目(No.2021C01190,2020C01008);国家重点研发计划青年科学家项目(No.2021YFB3501600)。

摘　　要：目的:研究了非金属元素Si掺杂对Pr_(0.5)Sr_(0.5)MnO_(3)(x=0.00、0.05、0.10)体系样品的结构、磁性能和磁热效应的影响。方法:通过传统固相烧结法制备了钙钛矿锰氧化物系列样品,利用粉末X射线衍射仪对样品的结构进行了表征,通过综合物性测量系统测量了样品的磁性和磁热性能。结果:随着Si的掺杂浓度的增大,样品在室温下呈正交结构,样品的居里温度(Curie temperature,T_(C))从294 K增大到305 K,样品的磁熵变(magnetic entropy change,-ΔS_(M))在外加磁场为5 T时从3.09 J/(kg·K)增大到3.70 J/(kg·K),根据Bonilla准则确定样品由一级相变转变为二级相变,相对制冷效率(relative cooling power,RCP)的值在x=0.05时,达到最大为69.2 J/kg。结论:Si的掺杂使得样品居里温度提高至室温附近,并且磁热性能也得到了增强,使得Pr_(0.5)Sr_(0.5)MnO_(3)成为良好的潜在制冷工质。Aims:The structure,magnetic properties and magnetocaloric effect of the Pr_(0.5)Sr_(0.5)MnO_(3)Mn_(1-x)Si_(x)O_(3)(x=0.00,0.05,0.10)system doped with non-metallic element Si were investigated.Methods:The perovskite manganites were prepared by the traditional solid-state reaction method.The structure was characterized by powder X-ray diffraction;and the magnetic properties of the samples were measured by the Physical Property Measurement System.Results:With the increase of the content of Si,the samples had an orthorhombic crystal structure at room temperature.The Curie temperature of the samples increased from 294 K to 305 K;and the magnetic entropy change(-ΔS_(M))of the samples increased from 3.09 J/(kg·K)to 3.70 J/(kg·K)under the magnetic field of 5 T.Based on the Bonilla s criteria,the phase transition of samples changed from the first-order to the second-order phase transition.For the sample of x=0.05,the relative cooling power(RCP)reached 69.2 J/kg with a magnetic entropy change of 1.54 J/kg·K.Conclusions:The doping of Si increases the Curie temperature of the samples to room temperature.What s more,the magnetocaloric effect and Curie temperature are also enhanced,which provides the possibility for Pr_(0.5)Sr_(0.5)MnO_(3)to become a good potential refrigerant.

关 键 词：磁制冷 钙钛矿锰氧化物 磁热效应 磁熵变 

分 类 号：TB64[一般工业技术—制冷工程]