Tuning the spontaneous exchange bias effect in La1.5Sr0.5CoMnO6 with sintering temperature

Abstract

Here, we present a study of the influence of microstructure on the magnetic properties of polycrystalline samples of the La1.5Sr0.5CoMnO6 double perovskite, with primary attention to the spontaneous exchange bias effect, a fascinating recently discovered phenomena for which some materials exhibit unidirectional magnetic anisotropy after being cooled in zero magnetic fields. By sintering La1.5Sr0.5CoMnO6 at different temperatures, we obtained samples with distinct average grain sizes, ranging from 1.54 to 6.65 mu_m. A detailed investigation of the material's structural, morphologic, electronic, and magnetic properties using X-ray powder diffraction, powder neutron diffraction, X-ray absorption near edge structure spectroscopy, scanning electron microscopy, and AC and DC magnetometry has revealed a systematic enhancement of the exchange bias effect with increasing the average grain size. This evolution is discussed in terms of changes in the material's porosity and grain morphology and its influence on the exchange couplings at the magnetic interfaces.

10 pages, 6 figures

References in corpus (8)

• Ferromagnetic cluster spin-glass behavior in PrRhSn3
• Spin-glass behavior in Ni-doped La1:85Sr0:15CuO4
• Tuning the spontaneous exchange bias effect with Ba to Sr partial substitution in La${}_{1.5}$(Sr${}_{0.5-x}$Ba${}_x$)CoMnO${}_6$
• A phenomenological model for the spontaneous exchange bias effect
• Griffiths phase and spontaneous exchange bias in La${}_{1.5}$Sr${}_{0.5}$CoMn${}_{0.5}$Fe${}_{0.5}$O${}_6$
• The spontaneous exchange bias effect in La2-xCaxCoMnO6 series
• Absence of zero-field-cooled exchange bias effect in single crystalline La2-xAxCoMnO6 (A = Ca, Sr) compounds
• Structural transitions and spontaneous exchange bias in La2-xBaxCoMnO6 series