Synthesis and Properties of Lanthanum Sodium Manganate Perovskites Crystals
| Autor: | Kandalam V. Ramanujachary, Ian D. Fawcett, W. H. McCarroll, Martha Greenblatt |
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| Rok vydání: | 1999 |
| Předmět: |
Electrolysis
Valence (chemistry) Magnetoresistance Chemistry Inorganic chemistry Analytical chemistry Sodium manganate chemistry.chemical_element Condensed Matter Physics Magnetic susceptibility Electronic Optical and Magnetic Materials law.invention Inorganic Chemistry chemistry.chemical_compound law Materials Chemistry Ceramics and Composites Lanthanum Curie temperature Physical and Theoretical Chemistry Solid solution |
| Zdroj: | Journal of Solid State Chemistry. 146:88-95 |
| ISSN: | 0022-4596 |
| DOI: | 10.1006/jssc.1999.8312 |
| Popis: | Crystals up to 4 mm on the edge of sodium-substituted lanthanum manganates with the rhombohedral perovskite structure have been grown for the first time using fused salt electrolysis at 980–1000°C. Cs 2 MoO 4 –MoO 3 mixtures have been employed as solvents. Substitution of Na for La appears to be limited to about 12 at.%. All the phases prepared have an average Mn valence of 3.26(2) which is a result of decreasing A-site vacancies as the Na content is increased. The Curie and insulator–metal transition temperatures increase with increasing Na content with values of 300–320 K being observed for samples containing 10–12 at.% Na. Magnetoresistance values (5 T field) of ∼62% at 300 K with a maximum value of 76% at 280 K were observed for a sample of composition Na 0.099 La 0.889 Mn 0.996 O 3 . |
| Databáze: | OpenAIRE |
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