authors |
Tkach, A; Okhay, O; Nuzhnyy, D; Petzelt, J; Vilarinho, PM |
nationality |
International |
journal |
MATERIALS |
author keywords |
perovskites; polar dielectrics; thin films; infrared spectroscopy |
keywords |
RAMAN-SCATTERING; SRTIO3; DEPENDENCE; DISPERSION; LOSSES |
abstract |
Strontium titanate-based materials with ferroelectric or relaxor-like properties have drawn vast attention as polar dielectrics for electronics and telecommunications. Here, we study the lattice dynamics in sol-gel-derived Sr1-1.5xBixTiO3 thin films with x = 0.0053 and 0.167, deposited on Al2O3 substrates, using a variable-temperature far-infrared spectroscopy in a transmittance mode. Bi doping, known to induce a low-frequency dielectric relaxation in SrTiO3 (ST) ceramics and films, due to off-centre dopant ion displacements generating electric dipoles, is shown to affect the polar phonon behaviour of thin films. We show that in weakly Bi-doped films, the low-frequency polar TO1 mode softens on cooling but less than in undoped ST. In heavily Bi-doped ST films, this mode displays no significant frequency variation with temperature from 300 to 10 K. The polar phonon behaviour of polycrystalline Bi-doped ST thin films is comparable with that of Bi-doped ST ceramics, which exhibit dielectric relaxations and harden soft-mode behaviour instead of the ferroelectric phase transition. |
publisher |
MDPI |
isbn |
1996-1944 |
year published |
2021 |
volume |
14 |
issue |
21 |
digital object identifier (doi) |
10.3390/ma14216414 |
web of science category |
9 |
subject category |
Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter |
unique article identifier |
WOS:000718389300001
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ciceco authors
impact metrics
journal analysis (jcr 2019):
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journal impact factor |
3.057 |
5 year journal impact factor |
3.424 |
category normalized journal impact factor percentile |
58.121 |
dimensions (citation analysis):
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altmetrics (social interaction):
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