Electronic structures and magnetic properties of a II-II-V based diluted magnetic semiconductor Ba1−xKx(Cd1−yMny)2As2 with decoupled charge and spin doping. (13th October 2016)

• Record Type: Journal Article
• Authors: Yang, Juntao; Luo, Shijun; Cheng, ZhenXiang; Wang, Xiaotian; Xiong, Yongchen; Amel, Laref
• Is Part Of: Materials research express. Volume 3:Number 10(2016)
• Publication Date: 2016-10-13
• Subjects: electronic structure -- diluted magnetic semiconductor -- decoupled charge and spin doping -- itinerant holes; Materials science -- Research -- Periodicals; Materials science -- Periodicals; 620.11
• DOI: 10.1088/2053-1591/3/10/105903
• Languages: English
• ISSNs: 2053-1591

Abstract

Abstract: By using the density functional theory within Perdew–Burke–Ernzerh of generalized gradient approximation, the electronic structures and magnetic properties of Ba 1 − x K x ( Cd 1 − y Mn y ) 2 As 2 system were investigated. Undoped compound BaCd 2 As 2 is a semiconductor crystallized with a hexagonal CaAl 2 Si 2 − type structure. After local moments doping via isovalent (Cd 2+, Mn 2+ ) substitutions, Ba ( Cd 1 − y Mn y ) 2 As 2 is antiferromagnetic system, which is attributed to the superexchange interactions between the Mn 2+ ions in the high spin state. With itinerant holes introduced via off-stoichiometry (Ba 2+, K + ) substitutions, Ba 1 − x K x ( Cd 1 − y Mn y ) 2 As 2 system (except for the system doped with the most nearest neighbor Mn-Mn pair) changes from antiferromagnetic to ferromagnetic, resulted from the indirect exchange interactions based on p − d exchange coupling between As 4 p and Mn 3 d orbitals. Moreover, hypothetical supercells Ba 10 K 2 Cd 22 Mn 2 As 24 with different lattice parameters under mechanical compression and expansion were calculated to study the effect of itinerant holes on the Curie temperature. Our results reveal that the Ba 1 − x K x ( Cd 1 − y Mn y ) 2 As 2 system with small lattice has more holes amount and better holes mobility, leading to a higher Curie temperature for the CaAl 2 Si 2 -type structure DMSs.