Half metallic Co2TiGe-a theoretical and experimental investigation
Half metallic Co2TiGe-a theoretical and experimental investigation
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DOI：
10.1016/j.jmmm.2010.08.005
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发表时间：
2011
影响因子：
2.7
通讯作者：
G. Prathiba;S. Venkatesh;M. Rajagopalan;N. Kumar
中科院分区：
文献类型：
--
作者：
G. Prathiba;S. Venkatesh;M. Rajagopalan;N. Kumar
采用第一性原理计算方法研究了半金属Co2 TiGe的电子结构和磁性。电子结构计算使用两种不同的参数化方案。在TB-LMTO方法中，用LDA方法得到的少子自旋态的带隙比用FP-LAPW方法中的GGA方法得到的带隙小。为了探索半金属特性，在氩气保护下，采用电弧熔炼法制备了Co2 TiGe块体材料。由2K下的饱和磁化强度确定的每分子单位的磁矩为1.9μB，这接近于理论计算值2μB。对低温输运和磁输运性质的详细分析显示出半金属的特征，如低温电阻率的T_9/2依赖性，低于20 K时电阻率的温度依赖性可忽略，以及在100 K附近从正到负MR的交叉。
Using first principle calculations the electronic structure and magnetic properties of the half metallic Co2TiGe was investigated. The electronic structure calculations were performed using two different parameterization schemes. The band gap obtained in the minority spin state using LDA scheme in TB-LMTO method was smaller than that obtained using GGA scheme in FP-LAPW method. To explore the half metallic property experimentally bulk Co2TiGe was synthesized by arc melting under argon atmosphere. The magnetic moment per formula unit determined from saturation magnetization at 2K was 1.9μB, which was close to the theoretically calculated value of 2μB. A detailed analysis of the low temperature transport and magnetotransport properties exhibit characteristic features of half metals such as T9/2dependence of low temperature resistivity, negligible temperature dependence of resistivity below 20K and a cross over from positive to negative MR around 100K.