title: Magnetic structure and electronic study of complex oxygen-deficient manganites.
abstract: Neutron diffraction and X-ray absorption near-edge structure (XANES) studies have been performed in La0.5Ca0.5MnO2.5, La0.5Sr0.5MnO2.5 and Nd0.5Sr0.5MnO2.5 oxygen-deficient perovskite compounds obtained by topotactic reduction. They all exhibit a brownmillerite structure with G-type antiferromagnetic ordering. Mn2+, Mn3+ and Mn4+ coexist at the octahedral sites, whereas only Mn2+ is placed in the tetrahedral positions. A magnetic moment of 1.6 microB has been detected at the tetrahedral layers, which can be explained by assuming Mn2+ is in a low-spin configuration.
authors.affiliation: Dpto. Química Inorgánica, Facultad de Químicas, Universidad Complutense de Madrid, 28040 Madrid (Spain), Fax: (+34) 91-3944342.|Instituto de Magnetismo Aplicado, UCM-CSIC-ADIF, Las Rozas, P.O. Box 155, 28230 Madrid (Spain).
authors.forename: Raquel
authors.initials: R
authors.lastname: Cortés-Gil
authors.affiliation: Dpto. Química Inorgánica, Facultad de Químicas, Universidad Complutense de Madrid, 28040 Madrid (Spain), Fax: (+34) 91-3944342.
authors.forename: María
authors.initials: M
authors.lastname: Hernando
authors.affiliation: Dpto. Química Inorgánica, Facultad de Químicas, Universidad Complutense de Madrid, 28040 Madrid (Spain), Fax: (+34) 91-3944342.
authors.forename: M Luisa
authors.initials: ML
authors.lastname: Ruiz-González
authors.affiliation: Instituto de Ciencia de Materiales, CSIC, Sor Juana Inés de la Cruz s/n, 28049 Madrid (Spain).
authors.forename: Eva
authors.initials: E
authors.lastname: Céspedes
authors.affiliation: Instituto de Ciencia de Materiales, CSIC, Sor Juana Inés de la Cruz s/n, 28049 Madrid (Spain).
authors.forename: Carlos
authors.initials: C
authors.lastname: Prieto
authors.affiliation: Instituto de Magnetismo Aplicado, UCM-CSIC-ADIF, Las Rozas, P.O. Box 155, 28230 Madrid (Spain).|Instituto de Ciencia de Materiales, CSIC, Sor Juana Inés de la Cruz s/n, 28049 Madrid (Spain).
authors.forename: José M
authors.initials: JM
authors.lastname: Alonso
authors.affiliation: Instituto de Magnetismo Aplicado, UCM-CSIC-ADIF, Las Rozas, P.O. Box 155, 28230 Madrid (Spain).|Dpto. Química Inorgánica y Bioinorgánica, Facultad de Químicas, Universidad Complutense de Madrid, 28040 Madrid (Spain).
authors.forename: María
authors.initials: M
authors.lastname: Vallet-Regí
authors.affiliation: Instituto de Magnetismo Aplicado, UCM-CSIC-ADIF, Las Rozas, P.O. Box 155, 28230 Madrid (Spain).|Dpto. Física de Materiales, Facultad de Físicas, Universidad Complutense de Madrid, 28040-Madrid (Spain).
authors.forename: Antonio
authors.initials: A
authors.lastname: Hernando
authors.affiliation: Dpto. Química Inorgánica, Facultad de Químicas, Universidad Complutense de Madrid, 28040 Madrid (Spain), Fax: (+34) 91-3944342.|Instituto de Magnetismo Aplicado, UCM-CSIC-ADIF, Las Rozas, P.O. Box 155, 28230 Madrid (Spain).
authors.forename: José M
authors.initials: JM
authors.lastname: González-Calbet