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Micro‐Raman study of orbiton–phonon coupling in YbVO 3
Author(s) -
Roberge B.,
Jandl S.,
Nugroho A. A.,
Palstra T. T. M.
Publication year - 2012
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.3006
Subject(s) - monoclinic crystal system , orthorhombic crystal system , phonon , raman spectroscopy , jahn–teller effect , coupling (piping) , condensed matter physics , chemistry , crystallography , materials science , crystal structure , physics , optics , ion , organic chemistry , metallurgy
First‐order and multiphonon Raman active excitations are studied in YbVO 3 as a function of temperature in the orthorhombic and monoclinic phases. Below T ≃ 170 K, a G‐type orbital ordering with a concomitant monoclinic transition occurs. They enhance the phonon polarizabilities, allowing the resolution of room‐temperature bands, and activate new excitations around 700 cm −1 . Below T ∼ 65 K, the 700 cm −1 excitations disappear, indicating a C‐type orbital ordering and a return to the orthorhombic structure. The observed phonon combinations around 1400 cm −1 with a dominant Jahn‐Teller vibration at ∼690 cm −1 reflect a possible orbiton‐phonon coupling. Copyright © 2011 John Wiley & Sons, Ltd.