Magnetic ordering and structural stability of La2/3Sr1/3MnO3/SrTiO3 (001) interfaces: A density-functional theory study

Authors

  • Li Yong Chen,

    Corresponding author
    1. Shaanxi Key Laboratory of Condensed Matter Structures and Properties, Northwestern Polytechnical University, Xi'an 710072, Shaanxi, P. R. China
    • Shaanxi Key Laboratory of Condensed Matter Structures and Properties, Northwestern Polytechnical University, Xi'an 710072, Shaanxi, P. R. China.
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  • Chang Le Chen,

    Corresponding author
    1. Shaanxi Key Laboratory of Condensed Matter Structures and Properties, Northwestern Polytechnical University, Xi'an 710072, Shaanxi, P. R. China
    • Phone: +86 29 88431670, Fax: +86 29 88431670
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  • Ke Xin Jin,

    1. Shaanxi Key Laboratory of Condensed Matter Structures and Properties, Northwestern Polytechnical University, Xi'an 710072, Shaanxi, P. R. China
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  • Su Fang Wang,

    1. College of Physics and Information Technology, Shaanxi Normal University, Xi'an 710062, Shaanxi, P. R. China
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  • Xiu Juan Du

    1. State Key Laboratory of Solidification Processing, School of Materials Science and Engineering, Northwestern Polytechnical University, Xi'an 710072, Shaanxi, P.R. China
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Abstract

The magnetic ordering and relative structural stability (phase diagram) of La2/3Sr1/3MnO3/SrTiO3 (LSMO/STO) (001) interfaces are considered by performing generalized gradient approximation plus on-site Coulomb correction calculations. A potential antiferromagnetic alignment between the interface layer and bulk is conjectured for the b-type LSMO/STO (001) interface where the atomic-layer stacking near interface is equation imageLaO[BOND]MnO2[BOND]LaO[BOND]MnO2[BOND]SrO[BOND]MnO2[BOND]SrO[BOND]TiO2equation image (SrO termination). This is in qualitative agreement with the fact that suppression of ferromagnetism at the SrO-terminated (001) interface is found at some experiments. The small magnetic exchange energies, for the SrO-terminated LSMO/STO (001) interfaces, suggest that Mn spins at the interface are likely to reverse as the temperature changes. Hence, possible magnetic reconstructions will be expected to occur at the SrO-terminated (001) interfaces when temperature increases. Under thermodynamic equilibrium, the calculated phase diagrams show that, with the exception of the c-type (001) interface where the atomic-layer stacking near interface is equation imageLa2/3Sr1/3O[BOND]MnO2[BOND]SrO[BOND]TiO2equation image (SrO termination), all other considered LSMO/STO (001) interfaces may be stabilized in the proper conditions. The spin-resolved density of states shows that high spin-transport behaviors could be achieved at the ferromagnetic TiO2-terminated (001) interfaces. The results of the calculations can compare favorably with the experimental results for the LSMO/STO (001) junctions.

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