Magnetic properties of Co3O4 nanoparticles on graphene substrate

Antiferromagnetic nanoparticles have attracted tremendous research interests due to the exhibiting magnetization reversal by quantum tunneling. However, the magnetic properties vary with the inter-particle separation owing to the strong magnetostatic interaction. Thus, a suitable synthetic method is needed to make the antiferromagnetic nanoparticles well-dispersed. Here a facile low-temperature hydrothermal method was used to fabricate the graphene-Co3O4 nanocomposites. The Co3O4 antiferromagnetic nanoparticles have a monodispersed grain size and anchor uniformly on the graphene surface. Compared with the pure Co3O4 nanoparticles with the similar size distribution, the graphene-Co3O4 nanocomposites present different magnetic properties, including the higher magnetization and the lower blocking temperature. It is deduced that the graphene matrix prevents the aggregation of Co3O4 nanoparticles which leads to the differences of magnetic properties. (C) 2017 Elsevier B.V. All rights reserved.