Colossal magnetoresistance in the transition-metal zintl compound Eu14MnSb11
Colossal magnetoresistance in the transition-metal zintl compound Eu14MnSb11
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DOI：
10.1021/cm9704241
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发表时间：
1997-12-01
影响因子：
8.6
通讯作者：
Webb, DJ
中科院分区：
文献类型：
--
作者：
Chan, JY;Kauzlarich, SM;Webb, DJ
对过渡金属锌化合物Eu14MnSb11的单晶样品进行了磁阻测量。Eu14MnSb11是第一个测量到磁阻效应的Ca14AlSb11结构化合物。在92K和5T下，Delta Rho/Rho(0)=-36%；在5K和5T下，Delta Rho/Rho(0)=-42%，观察到巨磁电阻效应。在铁磁-顺磁相变(92K)处观察到巨磁电阻。在第二磁相变(15K)以下观察到较大的负磁电阻，这归因于Eu2+晶格的场致反铁磁-铁磁有序。MR相对于晶轴是高度各向异性的。在92K以下和92K以上，Rho(H)曲线的曲率都发生了明显的变化，表明在两个不同的温度范围内，载流子的磁散射有两种不同的机制。
Magnetoresistance measurements have been carried out on single-crystal sample of the transition-metal Zintl compound Eu14MnSb11. Eu14MnSb11 is the first compound of the Ca14AlSb11 structure type in which magnetoresistive effects have been measured. Colossal magnetoresistance (CMR) at 92 K and 5 T with Delta rho/rho(0) = -36% and at 5 K and 5 T with Delta rho/rho(0) = -42% were observed. CMR is observed at the ferromagnetic-paramagnetic phase transition (92 K). A large negative magnetoresistance is observed below the second magnetic transition (15 K) and is attributed to a field-induced antiferromagnetic-ferromagnetic ordering of the Eu2+ lattice. The MR is highly anisotropic with respect to the crystallographic axes. A sign change in the curvatures of rho(H) curves below and above 92 K has been observed, indicating that two different mechanisms are responsible for the magnetic scattering of the carriers in two separate temperature regions.