Role of cobalt cations in short range antiferromagnetic Co 3 O 4 nanoparticles: a thermal treatment approach to affecting phonon and magnetic properties

We report the phonon and magnetic properties of various well-stabilized Co 3 O 4 nanoparticles. The net valence in cobalt (II)/(III) cation can be obtained by subtracting the Co 2+ ions in tetrahedral interstices and Co 3+ ions in the octahedral interstices, respectively, which will possess spatial inhomogeneity of its magnetic moment via Co 2+ in tetrahedra and Co 3+ in octahedral configurations in the normal spinel structure. Furthermore, the distribution of Co 2+ /Co 3+ governed by various external (magnetic field and temperature) and internal (particle size and slightly distorted CoO 6 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 Co 3 O 4 .