第一性原理研究Hg2CuTi型Heusler合金Ti2FeB的磁性和半金属性

摘要

By using generalized gradient approximation (GGA) scheme within the density functional theory (DFT),the electronic and magnetic properties of Hg2CuTi-type Heusler alloy Ti2FeB were investigated.The results reveal that a 100％ spin polarization appears at Fermi level (εF) in Ti2FeB and it is maintained during Ti2FeB lattice range of 5.1 (A)～6.2 (A) Ti2 FeB is one of stable Half-Metallic Ferromagnets (HMF) with a spin-minority gap of 0.5 eV and total magnetic moment of 1μBsper unit cell.Our studies also indicate that the competition between RKKY-type indirect exchange and direct hybridization of d-electronic atoms plays a dominating role in determining the magnetism.%基于密度泛函理论的GGA计算,我们具体研究了Hg2 CuTi型Heusler合金Ti2 FeB的电子结构和磁性质,结果发现Ti2FeB合金在其费米面处存在100％的自旋极化,并在5.1～6.2(A)晶格范围内被保留.Ti2FeB具有大约0.5 eV的半金属带隙和1μB的原胞总磁矩,是一个稳定的半金属铁磁体.此外,我们的研究也表明RKKY型间接交换和d电子杂化在决定合金磁性质中起决定性作用.