Magnetic Interactions and Band Gaps of the (CrO$_2$)$_2$/(MgH$_2$)$_n$ Superlattices
Wanfei Shan1, Jiangtao Du1, and Weidong Luo1,2*
1Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China 2Institute of Natural Sciences, Shanghai Jiao Tong University, Shanghai 200240, China
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 CrO$_2$, with a thickness of two atomic layers, together with insulating MgH$_2$ are constructed. Systematic theoretical studies on the (CrO$_2$)$_2$/(MgH$_2$)$_n$ ($n = 2, 3, 4, 5, 6$) 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 MgH$_2$ 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.
(Density functional theory, local density approximation, gradient and other corrections)
引用本文:
. [J]. 中国物理快报, 2022, 39(11): 117501-.
Wanfei Shan, Jiangtao Du, and Weidong Luo. Magnetic Interactions and Band Gaps of the (CrO$_2$)$_2$/(MgH$_2$)$_n$ Superlattices. Chin. Phys. Lett., 2022, 39(11): 117501-.
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