Role of cobalt cations in short range antiferromagnetic Co3O4 nanoparticles: a thermal treatment approach to affecting phonon and magnetic properties

摘要

We report the phonon and magnetic properties of various well-stabilized Co3O4 nanoparticles. The net valence in cobalt (II)/(III) cation can be obtained by subtracting the Co²⁺ ions in tetrahedral interstices and Co³⁺ ions in the octahedral interstices, respectively, which will possess spatial inhomogeneity of its magnetic moment via Co²⁺ in tetrahedra and Co³⁺ in octahedral configurations in the normal spinel structure. Furthermore, the distribution of Co²⁺/Co³⁺ governed by various external (magnetic field and temperature) and internal (particle size and slightly distorted CoO6 octahedra) sources, have led to phenomena such as a large redshift of phonon-phonon interaction and short-range magnetic correlation in the inverse spinel structure. The outcome of our study is important in terms of the future development of magnetic semiconductor spintronic devices of Co3O4.