Universal link of magnetic exchange and structural behavior under pressure in chromium spinels

Article

关键词: INITIO MOLECULAR-DYNAMICS;    TOTAL-ENERGY CALCULATIONS;    QUASI-RANDOM STRUCTURES;    AUGMENTED-WAVE METHOD;    BASIS-SET;    CRYSTAL;    TRANSITION;    METALS;    STRAIN;    OXIDES;   

DOI  :  10.1103/PhysRevB.97.184435

来源: SCIE

【 摘 要 】

We have conducted high-pressure x-ray diffraction studies on the MnCr2O4 and NiCr2O4 spinels at room temperature. Both compounds undergo pressure- induced structural transitions into diverse tetragonal modifications. Based on these experimental observations and our ab initio calculations, we show that the Cr-oxide spinels with magnetic A(2+) cations (A(2+) = Mn, Fe, Co, Ni) follow a similar trend as their chalcogenide counterparts with nonmagnetic A(2+) ions, i.e., the transition pressure is proportionally related with the magnitude of the Cr-Cr magnetic exchange interactions. Therefore, we reach the conclusion that the Cr-Cr magnetic exchange interactions alone suffice to account for the high-pressure behavior of these systems. Our results clearly depict the close relationship between the structural and magnetic degrees of freedom in Cr-bearing spinels.

【 授权许可】

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