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本文采用真空氩弧熔炼的方法制备了(Mn1-xFex)2Dy(x=0.0-1.0)系列样品,在800℃下进行热处理10 h,利用X射线衍射仪(XRD)、综合物性测量系统(PPMS)、电阻应变片法等测试方法系统研究了不同Fe替代量对Mn2Dy化合物的结构演变、磁性能和磁致伸缩性能的影响。研究结果表明,Mn2Dy化合物具有典型的MgC u2(C15型)面心立方(fcc)晶体结构,随着Fe替代量x的增加,(Mn1-xFex)2Dy化合物的晶胞体积和晶胞参数a、b、c逐渐减小,但始终保持fcc晶体结构不变;Mn2Dy化合物为反铁磁体,当Fe替代量x>0.5时,该化合物开始由反铁磁性向铁磁性转变,饱和磁化强度(Ms)可在~6.0-80.0 Am2/kg之间调控;反铁磁Mn2Dy几乎不显示磁致伸缩性能,随着Fe替代量的增加,磁致伸缩系数(λ)逐步提高且灵敏度越来越高,当x=0.9时在72 kA/m外场下λ最高可以达到350 ppm。机理探讨表明,铁磁性的Fe元素替代Mn后改变了Mn2Dy化合物的磁晶各向异性与磁性,从而影响了磁致伸缩性能。
In this paper, samples of (Mn1-xFex) 2Dy (x = 0.0-1.0) were prepared by vacuum argon arc melting and were heat treated at 800 ℃ for 10 h. The samples were characterized by X-ray diffraction (XRD), comprehensive physical property measurement system ), Resistance strain gauge method and other test methods systematically studied the effect of different Fe substitutions on the structural evolution, magnetic properties and magnetostriction properties of Mn2Dy compounds. The results show that the Mn2Dy compound has the typical fcc crystal structure of MgCu2 (C15 type). With the increase of Fe substitution amount x, the unit cell volume and unit cell parameters of (Mn1-xFex) b, c gradually decreased, but the crystal structure of fcc remained unchanged. The Mn2Dy compound was an antiferromagnetic material. When the amount of Fe substitution was> 0.5, the compound began to change from antiferromagnetism to ferromagnetism. The saturation magnetization (Ms) Can be controlled between ~ 6.0-80.0 Am2 / kg; antiferromagnetic Mn2Dy shows almost no magnetostriction, and as the substitution amount of Fe increases, the magnetostriction coefficient (λ) gradually increases and the sensitivity increases. When λ = up to 350 ppm at 72 kA / m with x = 0.9. Mechanism discussion shows that the substitution of ferromagnetic Fe element changes the magnetocrystalline anisotropy and magnetism of Mn2Dy compound, thus affecting the magnetostriction.