四元Heusler合金NiMnFeGa中Fe原子的磁性贡献

用熔炼和甩带的方法制备了组分为Ni₅₀Fe_xMn_25-xGa ₂₅(x=0—25) 的系列样品.x射线衍射实验结果表明，当Fe取代Mn的含量x＜17时，用熔炼和甩带的方法均 能合成高度有序的L2₁结构的Heusler相.而当x＞17时，普通熔炼方法只能得到 低有序度的 γ相，只有采用甩带急冷的方法才能获得高度有序的纯L2₁结构的化合物.根据 交流磁化率 和分子磁矩的测试结果，初步分析了Fe原子对化合物磁性的贡献，认为Fe原子占据了Mn原子 的位置后，具有高于一般含铁合金的原子磁矩，可达2.55—3.55μ_B.关键词：Heusler合金50Fe_xMn_25-xGa_{25')" href="#">Ni50FexMn25-xGa25}

The contribution of Fe atom to the magnetic moment of quaternary Heusler alloy N iMnFeGa

We have synthesized the pseudo-quaternary Heusler alloy Ni₅₀Mn_{25 -x}Fe _xGa₂₅(x=0—25) by arc-melting and melt-spinning techniques .The structure ,magnetic properties,and martensitic phase transformation were investigated.The thermoelastic martensitic transformation characteristics and x-ray diffraction c onfirmed the high chemical ordering L2₁ structure of our samples in t he whole doping range.The dopant of iron decreases the martensitic transformation tempera ture and increases the Curie temperature for the doping level of x＜17.The ferro magnetic contribution of Fe atoms in Ni_50.5Mn_25-xFe_{x< /sub>Ga24.5 h as been investigated in detail by precisely measuring the magnetization at 4K.It has been found that Fe atoms were indeed in Mn positions and contributed a loca lized moment up to 2.55—3.55μB.}