IFEG   20353
INSTITUTO DE FISICA ENRIQUE GAVIOLA
Unidad Ejecutora - UE
artículos
Título:
Synthesis, structural characterization and magnetic properties of the serie of double perovskites Ba1+xLa1-xMnSbO6 with 0.1≤x≤0.7
Autor/es:
D.M. ARCINIEGAS JAIME; G. TIRAO; J.A. ALONSO; F. POMIRO; G. CUELLO; M.C. BLANCO; V.M. NASSIF; R. CARBONIO
Revista:
JOURNAL OF ALLOYS AND COMPOUNDS
Editorial:
ELSEVIER SCIENCE SA
Referencias:
Lugar: Amsterdam; Año: 2017 vol. 704 p. 776 - 787
ISSN:
0925-8388
Resumen:
Double perovskites Ba1þxLa1xMnSbO6 were 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 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, 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 superparamagnetism for x ¼ 0.6 and 0.7. The analysis of the M vs H curves also shows the presence of a weak ferromagnetism which is generated by the canting of the spins in the antiferromagnetic matrix. Neutron Powder Diffraction data reveals that there is long range antiferromagnetic ordering below 20 K.