Hall effect measurements on epitaxial SmNiO3 thin films and implications for antiferromagnetism

Article

关键词: METAL-INSULATOR-TRANSITION;    RAY-ABSORPTION SPECTROSCOPY;    OXYGEN STOICHIOMETRY;    ELECTRONIC-STRUCTURE;    PHASE-TRANSITIONS;    POLARON MOTION;    DENSITY-WAVE;    RNIO3 R;    PEROVSKITES;    PRNIO3;   

DOI  :  10.1103/PhysRevB.87.125150

来源: SCIE

【 摘 要 】

The rare-earth nickelates (RNiO3) exhibit interesting phenomena such as unusual antiferromagnetic order at wave vector q = (1/2, 0, 1/2) and a tunable insulator-metal transition that are subjects of active research. Here we present temperature-dependent transport measurements of the resistivity, magnetoresistance, Seebeck coefficient, and Hall coefficient (R-H) of epitaxial SmNiO3 thin films with varying oxygen stoichiometry. We find that from room temperature through the high temperature insulator-metal transition, the Hall coefficient is holelike and the Seebeck coefficient is electronlike. At low temperature the Neel transition induces a crossover in the sign of R-H to electronlike, similar to the effects of spin density wave formation in metallic systems but here arising in an insulating phase similar to 200 K below the insulator-metal transition. We propose that antiferromagnetism can be stabilized by band structure even in insulating phases of correlated oxides, such as RNiO3, that fall between the limits of strong and weak electron correlation. DOI: 10.1103/PhysRevB.87.125150

【 授权许可】

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