摘要
用固相反应法制备了(La1-xDyx)2/3(Sr)1/3MnO3(x=0~0.20).X射线衍射分析表明,样品为单相钙钛矿菱面结构,不存在其他杂相.扫描电镜照片显示样品的颗粒均匀,平均粒径分布在200~300 nm之间.利用振动样品磁强计测量了样品的M-T曲线和居里温度附近的等温M-H曲线,研究了样品的居里温度和磁熵变随Dy掺杂量的变化规律.结果表明,随着Dy掺杂量的增加,系列样品的居里温度降低,磁熵变先增大后减小,在x=0.05处达到最大.
Polycrystallin samples of （La1-xDyx）2/3（Sr）1/3MnO3 are prepared by conventional soild-state reaction method. Analysis of the X-ray diffraction showed that the samples in this work were of the single perovskite-type phase with Rhombohedral structure. The scanning electron microscope observations show that all samples studied in this paper were constituted of homogeneous particles with a narrow particle-size distribution, ranging from 200 to 300 nm. The M - T curves and isothermal M- H curves near Tc were measured by using a vibrating sample magnetometer. The Curie temperature and the magnetic entropy change of the samples are studied based on the magnetic measurements. It was found that the Curie temperature Tc decreases with increasing x and the magnetic entropy change ｜△SM ｜ has a maximum at x = 0.05.
出处
《河北师范大学学报（自然科学版）》
CAS
北大核心
2008年第2期187-190,共4页
Journal of Hebei Normal University：Natural Science
基金
河北省自然科学基金(E2006000168)
关键词
磁卡效应
磁熵变
钙钛矿
居里温度
magnetocaloric effect
magnetic entropy change
perovskite
Curie temperature
