Heusler合金Co2-xFexVAl的电子结构、磁性和半金属性研究

张玉; 卢志红; 陈昌威; 方孙; 戴晨盼

文章摘要

Heusler合金Co2-xFexVAl的电子结构、磁性和半金属性研究

Electronic structure, magnetic properties and half-metallicity of Heusler alloy Co2-xFexVAl

投稿时间：2017-01-03

DOI：

中文关键词: Heusler合金铁掺杂半金属性磁矩费米能级态密度

英文关键词: Heusler alloy Fe doping half-metallicity magnetic moment Fermi energy level density of state

基金项目:国家自然科学基金资助项目(11574242).

作者	单位	E-mail
张玉	武汉科技大学材料与冶金学院,湖北武汉,430081	691144681@qq.com
卢志红	武汉科技大学材料与冶金学院,湖北武汉,430081
陈昌威	武汉科技大学材料与冶金学院,湖北武汉,430081
方孙	武汉科技大学材料与冶金学院,湖北武汉,430081
戴晨盼	武汉科技大学材料与冶金学院,湖北武汉,430081

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中文摘要:

基于密度泛函理论(DFT),使用广义梯度近似(GGA)研究了Heusler合金Co2-xFexVAl在不同Fe掺杂比例x时的电子结构、磁性和半金属性。结果表明,随着Fe掺杂比例x的增加,合金的晶格常数和磁矩均线性降低,分别满足了Vigard和Slater-Pauling规律；当x=1时,CoFeVAl合金的总磁矩与Co₂VAl(x=0)相比降低了50%,虽然费米面处出现了少量的态密度,丧失了半金属性,但其自旋极化率高达90%,仍被认为是一种很好的自旋电子学材料；此外,自旋向下带带隙宽度随x的增加逐渐变小,费米面向导带底移动,这不仅与X位原子间相互作用有关,还可能与Y位原子的轨道位置相关。

英文摘要:

Based on the density functional theory (DFT), the electronic structure, magnetism and half-metallicity of Heusler alloys Co2-xFexVAl (x=0,0.25,0.5,0.75,1) were studied by the generalized gradient approximation (GGA) method. The results show that the lattice constant and magnetic moment of alloys decrease linearly with the increase of Fe doping concentration, which meet the Vigard law and the Slater-Pauling behavior, respectively. Furthermore, although when x=1, small amount of density of states appear on the Fermi surface and the alloy lose its half metallicity, the spin polarization is as high as 90%. Considering the total magnetic moment of CoFeVAl is only 50% of that of Co₂VAl (x=0), it can still be regarded as a promising material for spintronic devices based on spin-transfer torque. In addtion, with the increase of x, the width of spin-down energy gap decreases and the Feimi level moves toward the bottom of conduction band, which indicates that the band gap is determined not only by the interaction behavior of atomic orbitals at X positions, but also by the orbital of atoms at position Y.

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