Ferromagnetism in LaCoO3: relationship between the crystal structure, morphology and magnetic properties

Abstract

It is known that in a weak magnetic field (H < 1 kOe) at T < T_C ≈ 87 K, rare-earth cobalt oxide LaCoO₃ has ferromagnetic properties. The physical mechanism of the emergence of ferromagnetism in LaCoO₃ still remains unclear. We provided experimental evidence of the ferromagnetism and crystal lattice interconnection – the cause of ferromagnetic ordering is near-surface (defects) structural stresses. A theoretical model is proposed, within the framework of which the mechanism of the emergence of the magnetically ordered state in LaCoO₃ is discussed.