info:eu-repo/semantics/article
Synthesis, structural characterization and magnetic properties of the series of double perovskites Ba1+xLa1−xMnSbO6with 0.1 ≤ x ≤ 0.7
Fecha
2017-05-15Registro en:
Arciniegas Jaimes, Diana Marcela; Blanco, Marìa Cecilia; Pomiro, Fernando; Tirao, German Alfredo; Nassif, Vivian M.; et al.; Synthesis, structural characterization and magnetic properties of the series of double perovskites Ba1+xLa1−xMnSbO6with 0.1 ≤ x ≤ 0.7; Elsevier Science Sa; Journal of Alloys and Compounds; 704; 15-5-2017; 776-787
0925-8388
1873-4669
CONICET Digital
CONICET
Autor
Arciniegas Jaimes, Diana Marcela
Blanco, Marìa Cecilia
Pomiro, Fernando
Tirao, German Alfredo
Nassif, Vivian M.
Cuello, Gabriel Julio
Alonso, José A.
Carbonio, Raul Ernesto
Resumen
Double 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 superparamagnetism for x = 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.