Synthesis, structural characterization and magnetic properties of the series of double perovskites Ba1+xLa1−xMnSbO6with 0.1 ≤ x ≤ 0.7

ARCINIEGAS JAIMES, DIANA M.; BLANCO, M. CECILIA; POMIRO, FERNANDO; TIRAO, GERMÁN; NASSIF, VIVIAN M.; CUELLO, GABRIEL J.; ALONSO, JOSÉ A.; CARBONIO, RAÚL E.

JOURNAL OF ALLOYS AND COMPOUNDS

ELSEVIER SCIENCE SA

Año: 2017 vol. 704 p. 776 - 776

0925-8388

ouble perovskites Ba1+xLa1−xMnSbO6were synthesized by traditional ceramic methods in air as polycrystalline powders. The 0.1 ≤ x ≤ 0.2 compounds belong to the I 2/m monoclinic space group, while the perovskites with x ≥ 0.3 belong to the I 4/m tetragonal space group. The effective presence of mixtures of Mn2+/Mn3+has been well established by X-ray Emission Spectroscopy. Ba1+xLa1−xMnSbO6(0.1 ≤ x ≤ 0.5) oxides display signs of superparamagnetism in the 40–160 K range, which arises from 3D-nanoclusters formed in regions which are rich in Mn2+/3+–O–Mn2+/3+superexchange paths originated by the antisite disorder. The analysis of the M vs H hysteresis loops shows that, as x increases, the number of 3D-nanoclusters rises and the number of magnetic ions in the 3D-nanoclusters decreases. The small 3D-nanoclusters cannot sustain magnetic order inside them and this is the reason for the absence of