通过真空电弧熔炼的方法制备了Gd1-xHoxCo2(x=0,0.2,0.4,0.6)系列化合物,利用XRD、SEM、VSM等分析设备对其结构及其磁性能进行了研究.结果表明,Gd1-xHxCo2系列化合物保持纯MgCu2类型的Laves相结构,并存在在少量的GdCo3相.该系列化合物的居里温度随着Ho含量的增加从399 K降低到了236 K,降低幅度达到了67%,但在5 T外场下磁熵变从3.3 J/(kg·K)增加到了4.0 J/(kg·K),变化幅度不大,说明Ho元素的替代在不改变磁熵变大小的同时可以有效地调节居里温度.另外还发现该化合物在5 T外场下的制冷量随着Ho含量的增加从158.3 J/kg增加到了254.6 J/kg,增加了60.8%.也讨论了晶体结构和磁性能之间的变化规律,为进一步调节磁性能奠定基础,使得这类材料在宽温区范围内的实际应用更有竞争力.
Gd1-xHoxCo2 (x=0, 0.2, 0.4, 0.6) compounds were prepared by vacuum arc melting.The structure and magnetic properties for all samples were investigated using XRD, SEM and VSM.The results show that the Gd1-xHxCo2 series compounds remain pure MgCu2 type Laves phase structure, but there exist impurity phase GdCo3 in the sample.With the increase of Ho contents, although the Curie temperature TC decreases from 399 to 236 K by 67 percent, magnetic entropy change ΔSM increases slightly from 3.3 to 4.0 J/(kg·K) under 5 T.The measurement results show that the substitution of Ho for Gd is effective methods to tune the Curie temperature while keeping the values of magnetic entropy change.Furthermore, The RC values increase from 158.3 to 254.6 J/kg by 60.8% with increasing of Ho contents under 0-5 T magnetic field.Furthermore, it is discussed about the relationship between the crystal structure and magnetic properties.Thus, it makes these materials more competitive for practical application in wide temperature regions.
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