Interfacial charge transfer induced antiferromagnetic metals and magnetic phase transition in (CrO2)m/(TaO2)n superlattices. (25th January 2023)

• Record Type: Journal Article
• Authors: Shan, Wanfei; Luo, Weidong
• Is Part Of: Journal of physics. Volume 35:Number 3(2023)
• Publication Date: 2023-01-25
• Subjects: antiferromagnetic (AFM) metals -- magnetic phase transition -- charge transfer; Condensed matter -- Periodicals; Matière condensée -- Périodiques; Vaste stoffen; Vloeistoffen; Natuurkunde; Electronic journals; Computer network resources; 530.4105
• DOI: 10.1088/1361-648X/aca19a
• Languages: English
• ISSNs: 0953-8984

Abstract

Abstract: As a class of remarkable spintronic materials, intrinsic antiferromagnetic (AFM) metals are rare. The exploration and investigation of AFM metals are still in its infancy. Based on first-principles calculations, the interface-induced magnetic phenomena in the (CrO2 ) m /(TaO2 ) n superlattices are investigated, and a new series of AFM metals is predicted. Under different ratios of m : n with varying valence states of Cr, the (CrO2 ) m /(TaO2 ) n superlattices exhibit three different phases, including the AFM metal, the AFM semiconductor, and the ferromagnetic (FM) metal. In the AFM semiconducting phases, the intra -CrO2 -monolayer magnetic exchange interaction is systematically discussed, corresponding to m = 1 or m = 2. Both the localization of the Cr 3 d orbitals and the crystal-field splitting are crucial for magnetic ordering in super-exchange interactions. Based on the analyses of the AFM semiconducting phases with m = 1 and m = 2, the mechanisms of AFM metallic phases with radios of m : n < 1 / 2 and 1 / 2 < m : n < 1 / 1 are discussed in detail. Additionally, the AFM metallic superlattices can be tuned into a FM metallic phase by applying strain in the c -direction, such as a compression of 7% in the (CrO2 )1 /(TaO2 )3 superlattice, and a tensile strain of 7% in the (CrO2 )2 /(TaO2 )3 superlattice. The phase diagram of the (CrO2 ) m /(TaO2 ) n superlattices is obtained as a function of the layer thickness. This work provides new insights about realizing and manipulating AFM metals in artificial superlattices or heterostructures in experiments.