Metal-insulator phase transitions of SmNiO 3 and PrNiO 3 :</…
1999; American Physical Society; Volume: 60; Issue: 8 Linguagem: Inglês
10.1103/physrevb.60.5304
ISSN1095-3795
AutoresMaría Andrea Mroginski, Néstor E. Massa, H.R. Salva, J. A. Alonso, María Jesús Martínez‐Lope,
Tópico(s)Advanced Condensed Matter Physics
ResumoTemperature dependence of reflectivity and transmission infrared spectra and photoinduced activity of $R{\mathrm{NiO}}_{3}$ $(R=\mathrm{Sm},$ Pr) were studied in order to elucidate the mechanism responsible for the metal-insulator transition at ${T}_{\mathrm{MI}}\ensuremath{\approx}135\mathrm{K}$ and \ensuremath{\approx}403 K, respectively. The reflectivity analysis and the agreement found between the small polaron theory and experimental conductivity allowed us to point out the electron-phonon interaction strength and therefore confirm the determinant participation of phonons in the transport properties of $R{\mathrm{NiO}}_{3}$ $(R=\mathrm{Pr},$ Sm). According to this, the metal-insulator transition at ${T}_{\mathrm{MI}}$ is directly related to self-trapped electrons in a polaronic medium.
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