A detailed study of the exchange bias effect and the interfacial electronic structure in Ni/Co3O4(011) is reported. Large exchange anisotropies are observed at low temperatures, and the exchange bias effect persists to temperatures well above the Neel temperature of bulk Co3O4, of about 40 K: to ~80 K for Ni films deposited on well ordered oxide surfaces, and ~150 K for Ni films deposited on rougher Co3O4 surfaces. Photoelectron spectroscopy measurements as a function of Ni thickness show that Co reduction and Ni oxidation occur over an extended interfacial region. We conclude that the exchange bias observed in Ni/Co3O4, and in similar ferromagnetic metallic/Co3O4 systems, is not intrinsic to Co3O4 but rather due to the formation of CoO at the interface.
@article{arxiv.1003.2478,
title = {Exchange bias and interface electronic structure in Ni/Co3O4(011)},
author = {C. A. F. Vaz and E. I. Altman and V. E. Henrich},
journal= {arXiv preprint arXiv:1003.2478},
year = {2015}
}
Comments
8 pages, 6 figures. Accepted for publication in Physical Review B.