2026-06-27T10:55:29Zhttps://docta.ucm.es/rest/oai/request

oai:docta.ucm.es:20.500.14352/447162023-08-26T13:59:46Zcom_20.500.14352_14col_20.500.14352_15

Garcia March, M. A. Jimenez Villacorta, F. Quesada, A. de la Venta, J. Carmona Tejero, Noemí Lorite, I. LLopis, J. Fernández, J. F. 2023-06-20T03:57:09Z 2023-06-20T03:57:09Z 2010-01-15 0021-8979 10.1063/1.3294649 https://hdl.handle.net/20.500.14352/44716 http://dx.doi.org/10.1063/1.3294649 http://scitation.aip.org We recently reported the observation of room temperature ferromagnetism in mixtures of ZnO and Co_3O_4 despite the diamagnetic and antiferromagnetic character of these oxides, respectively. Here, we present a detailed study on the electronic structure of this material in order to account for the unexpected ferromagnetism. Electrostatic interactions between both oxides lead to a dispersion of Co_3O_4 particles over the surface of ZnO larger ones. As a consequence, the reduction Co^(+3) -> Co^(2+) at the particle surface takes place as evidenced by x-ray absorption spectroscopy measurements and optical spectroscopy. This reduction allows explaining the observed ferromagnetic signal within the well established theories of magnetism in oxides. eng open access Surface magnetism in ZnO/Co_3O_4 mixtures journal article