1. Synthesis, structural, magnetic and electrical properties of nominal La0.67Ba0.33-xNaxMnO3(0 ≤ x ≤ 0.33) manganites
- Author
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Sobhi Hcini, Mohamed Oumezzine, H. Rahmouni, Sadok Zemni, and Michel Boudard
- Subjects
Materials science ,Physics ,QC1-999 ,Analytical chemistry ,Nanotechnology ,Chemical formula ,Metal ,Paramagnetism ,Magnetization ,Ferromagnetism ,Electrical resistance and conductance ,visual_art ,visual_art.visual_art_medium ,Ceramic ,Solid solution - Abstract
Complete nominal solid solutions La0.67Ba0.33-xNaxMnO3 (0 ≤ x ≤ 0.33) have been elaborated by ceramic route at 1200°C. ICPAES chemical analysis and XRD Rietveld structure refinement revealed that the nominal Na content is not achieved by our ceramic method. The chemical formula should be rather written as LaαBaβNaλMnO3- δ with a significantly lower Na content (λ), than the nominal one (x), and with a slight deficit (δ) in oxygen content, leading to the appearance of two minor secondary phases identified as Mn3O4 and Na0.55Mn2O4 . 1.5H2O. Magnetization and electrical resistance vs. temperature show paramagnetic/semiconductor - ferromagnetic/metallic transitions with only a slight decrease in magnetic and electrical transition temperatures when Na content increases. Such amount of this decrease is not expected according to the nominal Na content giving a significant difference between nominal and experimental Mn 4+ /Mn 3+ ratios.
- Published
- 2012