Premium
Orbital facilitated charge transfer originated phonon mode in Cr‐substituted PrFeO 3 : A brief Raman study
Author(s) -
Kumar Anil,
Umrao Sima,
Sagdeo Pankaj R.
Publication year - 2020
Publication title -
journal of raman spectroscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.748
H-Index - 110
eISSN - 1097-4555
pISSN - 0377-0486
DOI - 10.1002/jrs.5894
Subject(s) - raman spectroscopy , orthorhombic crystal system , phonon , valence (chemistry) , raman scattering , chemistry , octahedron , molecular vibration , crystallography , nuclear magnetic resonance , condensed matter physics , crystal structure , physics , optics , organic chemistry
We report the possible origin of orbital facilitated new Raman mode in orthorhombic perovskite PrFe 1‐x Cr x O 3 . For this purpose, resonance and power‐dependent Raman spectroscopy measurements have been carried out to understand the origin of local oxygen breathing mode in the mixed Fe–Cr orthorhombic perovskites through the orbital mediated charge transfer mechanism. It has been observed that multi‐phonon scattering is highly sensitive to the presence of mixed Fe–Cr ions and is absent in pure iso‐structural vacuum annealed PrFeO 3 . The Raman spectroscopy results infer a scaling in the intensity of octahedral breathing Raman mode around 660 cm −1 , which is attributed to the lattice rearrangement due to the transfer of an electron from Cr 3+ ( d 3 ) to Fe 3+ ( d 5 ) and results to d 2 –d 6 (Cr 4+ –O −2 –Fe 2+ ) configuration. The interactions of d 2 –d 6 configuration are different from d 3 –d 5 configuration, which leads to the octahedral lattice rearrangement and activates the new Raman mode. The charge transfer phenomenon is supported through first‐principle calculations and valence band spectroscopy.