Abstract
A mixed-valence state, formally denoted as (Formula presented) is observed in the 300 K Mössbauer spectra of the most reduced samples of (Formula presented) Upon cooling below the Verwey-type transition temperature (Formula presented) the component assigned to (Formula presented) separates into a high-spin (Formula presented) state and an (Formula presented) state with an unusually low internal field. The separation of the mixed-valence state at (Formula presented) is also confirmed by magnetic susceptibility measurements and differential scanning calorimetry. A model is proposed which accounts for the variation of the amount of the mixed-valence state with the oxygen content parameter w.
| Original language | English |
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| Pages (from-to) | 15251-15260 |
| Number of pages | 10 |
| Journal | Physical Review B - Condensed Matter and Materials Physics |
| Volume | 60 |
| Issue number | 22 |
| DOIs | |
| Publication status | Published - 1999 |
| MoE publication type | A1 Journal article-refereed |