摘要
采用固相反应法制备La(1-x)2/3Ca1/3MnO3(x=0.0,0.04)和(La0.7Y0.3)2/3Ca1/3MnO3系列样品,测量不同温度下的磁化强度—磁场曲线,计算样品的磁熵变,研究La空位掺杂和Y3+离子掺杂对磁热效应的影响。结果表明,La空位掺杂(x=0.04)的样品在居里温度附近磁熵变最大值为6.22 J/(kg.K),这比La2/3Ca1/3MnO3磁熵变最大值(6.26 J/(kg.K))稍有降低;而Y3+离子掺杂的样品在温度60 K时和磁场强度2 T下,其磁熵变最大值为0.568 J/(kg.K),并且磁熵变随温度变化有继续增大的趋势。这表明(La0.7Y0.3)2/3Ca1/3MnO3可以作为一定温区的磁致冷材料。
A series ofpolycrystal samples of La（1-x）2/3Ca1/3MnO3（x=0.0, 0.04） and （La0.7Y0.3）2/3Ca1/3MnO3 were prepared by standard solid-state reaction method. The curves of magnetic-field dependence on magnetization were measured at various temperatures and the entropy changes of the samples were calculated. The influences of La vacancy doping and y3＋ doping on magnetocaloric effect were investigated. The results show that the maximum value of magnetic entropy change for La vacancy doping sample （x=0.04） is 6.22 J/（kg·K） near Curie temperature To, which is a little smaller than that of La2/3Ca1/3MnO3 sample. The maximum value of magnetic entropy change for Y^3＋ doping sample is 0.568 J/（kg·K） at temperature of 60 K and in magnetic field of 2 T, and the magnetic entropy change increases with the increase of temperature, which indicates that the perovskite manganites are suitable candidates as working substances in magnetic refrigeration technology.
出处
《中国有色金属学报》
EI
CAS
CSCD
北大核心
2007年第12期2005-2009,共5页
The Chinese Journal of Nonferrous Metals
基金
江西省自然科学基金资助项目(0150014)
