Synthesis, structural characterization and magnetic properties of the series of double perovskites Ba1þxLa1xMnSbO6 with 0.1  x  0.7

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

JOURNAL OF ALLOYS AND COMPOUNDS

ELSEVIER SCIENCE SA

Lugar: Amsterdam; Año: 2017 vol. 704 p. 776 - 776

0925-8388

ouble perovskites Ba1þxLa1xMnSbO6 were synthesized by traditional ceramic methods in air aspolycrystalline powders. The 0.1 x 0.2 compounds belong to the I 2/m monoclinic space group, whilethe perovskites with x 0.3 belong to the I 4/m tetragonal space group. The effective presence ofmixtures of Mn2þ/Mn3þ has been well established by X-ray Emission Spectroscopy. Ba1þxLa1xMnSbO6(0.1 x 0.5) oxides display signs of superparamagnetism in the 40e160 K range, which arises from 3Dnanoclustersformed in regions which are rich in Mn2þ/3þeOeMn2þ/3þ superexchange paths originatedby the antisite disorder. The analysis of the M vs H hysteresis loops shows that, as x increases, thenumber of 3D-nanoclusters rises and the number of magnetic ions in the 3D-nanoclusters decreases. Thesmall 3D-nanoclusters cannot sustain magnetic order inside them and this is the reason for the absenceof superparamagnetism for x ¼ 0.6 and 0.7. The analysis of the M vs H curves also shows the presence of aweak ferrom