Theoretical approach for determining the relation between the morphology and surface magnetism of Co3O4

Precisely controlling the different aspects of the morphology and magnetic properties of metal oxides are fundamental to materials design. A theoretical approach, based on the Wulff construction and magnetization density (M) index, is presented to clarify the relation between the morphology and surface magnetism. The M index allows us to evaluate the uncompensated spins at the (100), (110), (111) and (112) surfaces of Co3O4 with a spinel structure. The investigated morphologies show an excellent agreement with the experimental results, with the main contribution coming from the (100) and (111) magnetic planes. The present results are also helpful in clarifying the intriguing magnetic properties reported for Co3O4 nanoparticles, suggesting that the same technique may serve as a guide for the study of shape-oriented magnetic materials. (C) 2017 Elsevier B.V. All rights reserved.