Cation distribution and magnetic characterization of the multiferroic cobalt manganese Co2MnO4 spinel doped with bismuth

Autor(es)

dos Santos, Maria Elenice ^{[1, 2]} ; Ferreira, Rafael Aparecido ^{[1, 2]} ; Lisboa-Filho, Paulo Noronha ^[3] ; Pena, Octavio ^[2]

Afiliação do(s) autor(es)

^[1] Univ Rennes 1, Inst Sci Chim Rennes, UMR 6226, F-35042 Rennes - France

^[2] UNESP Univ Estadual Paulista, Grp Mat Avancados, BR-17033360 Bauru, SP - Brazil

^[3] Univ Estadual Paulista, Dept Fis, Fac Ciencias, BR-17033360 Bauru, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of Magnetism and Magnetic Materials; v. 329, p. 53-58, MAR 2013.
• Citações Web of Science: 12

Resumo

The structural and magnetic properties of the cubic spinel oxide Co2MnO4 (Fd3m space group) doped with different concentrations of bismuth, were investigated by X-ray diffraction and SQUID magnetometry. The Bi3+ ions entering into the Co-III octahedral sites do not alter the effective moment, mu(eff) similar to 8.2 mu(B), whereas both the magnetization M-50 kOe at the highest field (50 kOe) and the field-cooled M-FC magnetizations increased when increasing the Bi content. The ferrimagnetic character of the parent compound, Co2MnO4, is maintained for all materials although the antiferromagnetic interactions Co2+-Co2+ are affected, resulting in higher values of the Curie-Weiss temperature. Due to the large ionic radius of Bi, octahedra distortions occur as well as valence fluctuations of the Mn ions, giving rise to Jahn-Teller effects and enhancing the exchange interactions. The off-center Bi3+ ion is responsible of non-centrosymmetric charge ordering and should lead to multiferroisme conditions for the BixCo2-xMnO4 material. (C) 2012 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 07/08072-0 - Pesquisa fundamental em supercondutividade e magnetismo - sistemas com potencial para aplicações: óxidos avançados e supercondutores dotados de estruturas artificiais
• Beneficiário: Wilson Aires Ortiz
• Modalidade de apoio: Auxílio à Pesquisa - Temático