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arXiv · 2205.04772

The spontaneous exchange bias effect in La2-xCaxCoMnO6 series

J. R. Jesus·L. Bufaiçal·E. M. Bittar
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Abstract

Structural, electronic and magnetic properties of polycrystalline La2-xCaxCoMnO6 (0 $\leq$ x $\leq$ 0.75) compounds are investigated by x-ray diffraction and magnetometry. All the samples have an orthorhombic structure and show a slight decrease in the unit cell with Ca-doping. Temperature-dependent magnetization measurements reveal a complex magnetic behavior with two ferromagnetic transitions. These transitions are ascribed to Co2+--Mn4+ and Co3+--Mn3+ couplings and suggest the presence of additional antiferromagnetic couplings in these disordered compounds. Field-dependent magnetization curves, measured after cooling the samples in a zero external magnetic field, reveal the spontaneous exchange bias (SEB) effect for the Ca-doped samples. The strengthening of the uncompensated magnetic coupling at the interfaces, caused by the increased antiferromagnetic phase, explains the increase of SEB with increasing the Ca-content.

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J. R. Jesus, L. Bufaiçal, E. M. Bittar. 2022-05-10. The spontaneous exchange bias effect in La2-xCaxCoMnO6 series. https://doi.org/10.1016/j.jmmm.2022.169402

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