Synthesis, structural characterization and magnetic properties of the series of double perovskites Ba1+xLa1−xMnSbO6with 0.1 ≤ x ≤ 0.7
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 mixtu...
| Authors: | , , , , , , , |
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| Format: | article |
| Status: | Published version |
| Publication Date: | 2017 |
| Country: | Argentina |
| Institution: | Consejo Nacional de Investigaciones Científicas y Técnicas |
| Repository: | CONICET Digital (CONICET) |
| Language: | English |
| OAI Identifier: | oai:ri.conicet.gov.ar:11336/64715 |
| Online Access: | http://hdl.handle.net/11336/64715 |
| Access Level: | Open access |
| Keyword: | Crystal Structure Double Perovskites Magnetic Measurements Order-Disorder Effects Powder Neutron Diffraction X-Ray Emission Spectroscopy https://purl.org/becyt/ford/1.4 https://purl.org/becyt/ford/1 |
| Summary: | 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. |
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