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研究了具有菱方Th2 Zn1 7型结构的Ce2 Fe1 6 Al化合物在居里温度TC 附近的磁性和磁熵变 .实验结果表明 ,在居里温度附近样品的磁特性符合二级相变规律 ,样品的居里温度为 2 75 8K .通过磁化强度与磁场和温度关系的测量 ,计算出临界指数 β=0 44± 0 0 1,γ=1 3 0 ± 0 0 1,δ =3 83 ± 0 0 1,临界指数 β ,γ ,δ基本满足标度率方程γ =β(δ- 1) ,但偏离三维Heisenberg模型的理论值 .Ce2 Fe1 6 Al化合物的磁熵变在居里温度处达到峰值 ,2T外磁场下的最大磁熵变为 1 95J kgK
The magnetic and magnetic entropy change of Ce2Fe1 6 Al compound with Th2 Zn1 7 type rhombus structure near the Curie temperature TC was studied.The experimental results show that the magnetic properties of the sample near the Curie temperature conform to the second- The Curie temperature is 2 75 8 K. The critical exponent β = 0 44 ± 0 0 1, γ = 130 ± 0 0 1, δ = 3 83 ± 0 0 were calculated by measuring the relationship between magnetization and magnetic field and temperature 1. The critical exponents β, γ and δ basically satisfy the scaling rate equation γ = β (δ-1), but deviate from the theoretical value of the three-dimensional Heisenberg model. The magnetic entropy change of Ce2 Fe1 6 Al peaks at the Curie temperature, The maximum magnetic entropy under 2T magnetic field becomes 1 95J kgK