NdIn3-xMnx合金化合物的结构和磁电输运性质

Structure and electromagnetic transport properties of compound NdIn_(3-x)Mn_x

本文应用非自耗真空电弧炉制备稀土NdIn3-xMnx(x=0,0.2,0.3,0.5)合金化合物.采用X射线粉末衍射(XRD)研究其相成分和结构,利用TREOR对衍射数据进行指标化,采用Rietveld全谱拟合分析方法测定了NdIn3-xMnx的晶体结构.结果表明:当x≤0.3时,为具有AuCu3型结构,空间群为Pm3m,Z=1,点阵常数a=4.640(6)-4.738(7);当x=0.5时,化合物中出现杂相In.在x≤0.3固溶区,Mn原子部分取代In原子占据3c(0.5,0.5,0)晶位,Nd原子占据1a(0,0,0)晶位.NdIn3-xMnx的磁化曲线显示:当x≤0.2时,呈现出顺磁结构;当x=0.3时,呈现出弱铁磁性和顺磁性的混合.NdIn2.7Mn0.3电阻率在0–300 K区间变化呈半金属性.

NdIn3-xMnx compounds have been prepared by arc melting, and their phase structures have been determined using powder X-ray diffraction. The crystal structures of NdIn3-xMnx are determined with Rietveld＇s method. It shows that NdIn3-xMnx crystallize in cubic AuCu3（x〈0.3） type structure with space group of Pm-3m and Z=1. The lattice parameters are a=4.641（6）-4.738（7） A. Nd atom occupies the la （0, 0, 0） position; In and Mn atoms are at the 3c（0.5, 0.5, 0） position. NdIn3-xMnx show mixture characters of weak ferromagnetic and paramagnetic properties for x=0.3 and paramagnetic characteristics for x〈0.3 at room temperature. The resistivity increases from 2.23 Ωμm to 2.53 Ωμm with increasing temperature from 0 to 300 K. The resistivity follows an equation of p=p0＋aT^n, where n〈2, it shows that Ndln3-xMnx intermetallic compounds are semimetals.