Nature of antiferromagnetic order in epitaxially strained multiferroic SrMnO3 thin films

Article

关键词: MUON SPIN RELAXATION;    LOW-ENERGY MUONS;    EXCHANGE BIAS;    PHASE-DIAGRAM;    METAL;    MAGNETORESISTANCE;    MANGANITES;    TRANSITION;    GENERATION;    PEROVSKITE;   

DOI  :  10.1103/PhysRevB.92.024419

来源: SCIE

【 摘 要 】

Epitaxial films of SrMnO3 and bilayers of SrMnO3/La0.67Sr0.33MnO3 have been deposited by pulsed laser deposition on different substrates, namely, LaAlO3 (001), (LaAlO3)(0.3)(Sr2AlTaO6)(0.7) (001), and SrTiO3 (001), allowing us to perform an exhaustive study of the dependence of antiferromagnetic order and exchange bias field on epitaxial strain. The Neel temperatures (TN) of the SrMnO3 films have been determined by low-energy muon spin spectroscopy. In agreement with theoretical predictions, TN is reduced as the epitaxial strain increases. From the comparison with first-principles calculations, a crossover from G-type to C-type antiferromagnetic orders is proposed at a critical tensile strain of around 1.6 +/- 0.1%. The exchange bias (coercive) field, obtained for the bilayers, increases (decreases) by increasing the epitaxial strain in the SrMnO3 layer, following an exponential dependence with temperature. Our experimental results can be explained by the existence of a spin-glass (SG) state at the interface between the SrMnO3 and La0.67Sr0.33MnO3 films. This SG state is due to the competition between the different exchange interactions present in the bilayer and favored by increasing the strain in the SrMnO3 layer.

【 授权许可】

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