Retentivity of spin state transitions in LaCoO3 with chemical disorder

Abstract

By means of structural refinements, magnetic susceptibility measurements and density functional theory based calculations; we study the physical properties of LaCoO₃ with Al substitutions. Despite Al substitutions, which result in a reduction of unit-cell volume, increased chemical disorder, and local octahedral distortions, we find that the thermally mediated low-spin and high-spin states in LaCoO₃ survive against the odds. The observed relative shift of the low-spin and high-spin representative peaks in the magnetic susceptibility data is determined to be of electronic origin via a change in the material’s chemical bonding properties. Our study reveals a strong interplay between bonding and disorder for the temperature dependent spin states of LaCoO₃.