Magnetic Interactions and Band Gaps of the (CrO2)2/(MgH2)n Superlattices. (1st October 2022)

• Record Type: Journal Article
• Authors: Shan, Wanfei; Du, Jiangtao; Luo, Weidong
• Is Part Of: Chinese physics letters. Volume 39:Number 11(2022)
• Publication Date: 2022-10-01
• Subjects: Physics -- Periodicals; Electronic journals; 530.05
• DOI: 10.1088/0256-307X/39/11/117501
• Languages: English
• ISSNs: 0256-307X

Abstract

Abstract : Lattice superlattices constructed with different materials such as ferromagnets and insulators at atomic scale provide an ideal platform for exploring many emergent physical phenomena. In the present work, a new type of superlattices composed of ferromagnetic half-metal CrO2, with a thickness of two atomic layers, together with insulating MgH2 are constructed. Systematic theoretical studies on the (CrO2 )2 /(MgH2 ) n ( n = 2, 3, 4, 5, 6) superlattices are carried out based on first-principles density-functional theory calculations. These superlattices are ferromagnetic semiconductors with similar intra -layer magnetic exchange couplings between Cr ions. As the thickness of the MgH2 layer increases, the magnetic exchange interaction between inter -layer Cr ions shows oscillating decaying behavior, while the energy band gaps show a small increase. The understanding of magnetic couplings in these superlattices provides a pathway for constructing new ferromagnetic semiconductors.