The effect of oxygen deficiency on the structural phase transition and electronic and magnetic properties of the spinel
| Autor: | Tsuyoshi Sasaki, Akihiko Koiwai, Jun Sugiyama, Naoki Kamegashira, Shoji Noda, Taroh Atsumi, Tatsumi Hioki |
|---|---|
| Rok vydání: | 1997 |
| Předmět: |
Phase transition
Valence (chemistry) Chemistry Transition temperature Spinel Inorganic chemistry Analytical chemistry engineering.material Condensed Matter Physics Magnetic susceptibility Tetragonal crystal system Differential scanning calorimetry Electrical resistivity and conductivity engineering General Materials Science |
| Zdroj: | Journal of Physics: Condensed Matter. 9:1729-1741 |
| ISSN: | 1361-648X 0953-8984 |
| DOI: | 10.1088/0953-8984/9/8/006 |
| Popis: | The effect of oxygen deficiency on a phase transition from cubic to tetragonal phase has been investigated for the spinels with by measurements of differential scanning calorimetry (DSC), magnetic susceptibility nuclear magnetic resonance ( NMR) and electronic resistivity . According to the DSC measurements, the transition temperature for a stoichiometric compound is determined to be K. As increases from zero to 0.066, the magnitude of is found to decrease by about 4 K; then, the magnitude of increases by about 41 K with further increase of up to 0.10; thus, the curve exhibits a broad minimum at around . This relationship between and is also observed by the measurements of NMR and . The dependence of on is considered to be a result of a competition between a decrease in the average valence of Mn ions and a dilution of the nearest-neighbour interaction between Mn ions. Both effects are caused by the oxygen deficiency; the former raises , whereas the latter reduces it. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|