Possible common ground for the metal-insulator phase transition in the rare-earth nickelates <i>R</i>NiO₃ (R = Eu, Ho, Y)
We report on the infrared spectra of <i>R</i>NiO₃ (<i>R</i> = E, Ho, Y). They provide evidence of phonon and insulating gap behavior and point to the monoclinic distortion at the metal-insulator (MI) transition as a feature for all <i>R</i>NiO₃ (<i>R</i&g...
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| Autores principales: | , , , , , , |
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| Formato: | Articulo |
| Lenguaje: | Inglés |
| Publicado: |
2002
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| Materias: | |
| Acceso en línea: | http://sedici.unlp.edu.ar/handle/10915/126303 |
| Aporte de: |
| Sumario: | We report on the infrared spectra of <i>R</i>NiO₃ (<i>R</i> = E, Ho, Y). They provide evidence of phonon and insulating gap behavior and point to the monoclinic distortion at the metal-insulator (MI) transition as a feature for all <i>R</i>NiO₃ (<i>R</i> ≠ La). We hypothesize that the intermediate paramagnetic phase (above T<sub>N</sub> and below T<sub>MI</sub> in <i>R</i>NiO₃ (<i>R</i> = Sm, Eu, Ho, Y) might be consequence of a self-doping effect, gradually triggering a phase segregation in electron-rich and electron-poor regions. This picture is concomitant to the temperature-dependent effect of octahedral tilting and distortion and self-trapped electrons in a polaronic medium. |
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