Spatial coherence of the insulating phase in quasi-two-dimensional LaNiO3 films

Article

关键词: RNIO3 PEROVSKITES;    METAL-INSULATOR;    CHARGE DISPROPORTIONATION;    ELECTRONIC-STRUCTURE;    ULTRATHIN FILMS;    TRANSITION;    EARTH;    SURFACE;   

DOI  :  10.1103/PhysRevB.98.014105

来源: SCIE

【 摘 要 】

The quasi-two-dimensional nature of LaNiO3 (LNO) thin films on SrTiO3(001) (STO) and LaAlO3(001)(LAO) substrates is examined. Although both samples undergo a metal-insulator transition with decreasing thickness, the spatial distributions of the insulating phase within the films differ from each other. The LNO cell volume of the insulating phase in LNO/STO is larger than that of the metallic phase, and the large cells remain at the interface in thick films with metallic conduction, suggesting a high oxygen-vacancy content at the interface. The cell volume of the insulating phase in LNO/LAO is smaller than that of the metallic phase, and the cell volume of the entire film changes coherently. The cell-volume decrease indicates that the bonding changes from bulklike to covalent.

【 授权许可】

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