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Pressure‐dependent Raman modes near the cubic‐tetragonal transition in strontium titanate
Author(s) -
Kiraci Ali,
Yurtseven Hamit
Publication year - 2018
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/jace.15279
Subject(s) - raman spectroscopy , tetragonal crystal system , strontium titanate , condensed matter physics , materials science , relaxation (psychology) , phonon , hydrostatic pressure , nuclear magnetic resonance , chemistry , crystal structure , thermodynamics , crystallography , optics , nanotechnology , physics , thin film , psychology , social psychology
The pressure dependence of the Raman frequency shifts of various Raman modes is calculated at room temperature using the volume data from the literature for the cubic‐tetragonal transition in SrTiO 3 . The isothermal mode Grüneisen parameters of those Raman modes are obtained, which decrease with increasing pressure for this molecular crystal. Calculated Raman frequencies are then used to predict the damping constant and the inverse relaxation time of those Raman modes as a function of pressure by means of the pseudospin‐phonon ( PS ) coupled model and the energy fluctuation ( EF ) model to describe the cubic‐tetragonal transition in SrTiO 3 . Also, the values of the activation energy are extracted for the Raman modes studied using both models ( PS and EF ). Our predicted damping constant and the inverse relaxation time for the Raman modes, can be compared with the experimental measurements close to the cubic‐tetragonal transition in SrTiO 3 .