摘要
采用密度泛函理论研究了空位和反位缺陷效应对四元Heusler合金CoFeTiSb电子结构的影响。结果表明,Vd_(Co)、Vd_(Fe)空位缺陷和Ti_(Sb)反位缺陷具有负的形成能,能保持85%以上的自旋极化率,在CoFeTiSb合金工业制备过程中自发形成几率较大;Vd_(Ti)、Vd_(Sb)空位缺陷和Fe_(Co)反位缺陷虽然费米面处自旋极化率为100%,仍保持半金属性,但正的形成能表明在制备过程中它们出现的几率较小。此外,Sb_(Co)、Sb_(Fe)、Sb_(Ti)、Co_(Ti)、Fe_(Ti)反位缺陷由于具有较大的形成能和半金属性破坏,自旋极化率不同程度降低。
Density functional theory（DFT）calculations were employed to investigate the effect of vacancy and antisite defects on the electronic structure of quaternary Heusler alloy CoFeTiSb.We found that Vd（Co）,Vd（Fe）vacancies as well as Ti（Sb）antisite defects were more likely to spontaneously occur as they had negative formation energies,which could keep at least 85% of spin polarization values in CoFeTiSb alloy.The half-metallic character was maintained for Vd（Ti）,Vd（Sb）vacancies and Fe（Co）antisite defects with 100%spin polarization at the Fermi level,and its positive values of formation energy suggested lower probabilities to occur during the growth of CoFeTiSb.Whereas,Sb（Co）,Sb（Fe）,Sb（Ti）,Co（Ti）,Fe（Ti）antisite defects had relatively high formation energies,their half-metallic character vanished and the spin polarization value declined.
出处
《材料导报》
EI
CAS
CSCD
北大核心
2016年第16期105-108,114,共5页
Materials Reports
基金
国家自然科学基金(11304410)
贵州省科技厅项目(黔科合J字[2014]2170号)
贵州省重点学科-物理学(黔学位办[2013]18号)
贵州省联合基金项目(黔科合LH字[2015]7025号)
