Phonons and relaxations in unfilled tetragonal tungsten-bronzes
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68378271%3A_____%2F21%3A00553887" target="_blank" >RIV/68378271:_____/21:00553887 - isvavai.cz</a>
Result on the web
<a href="http://perovskitesandotherfws.co-ac.com" target="_blank" >http://perovskitesandotherfws.co-ac.com</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.23647/ca.md20191227" target="_blank" >10.23647/ca.md20191227</a>
Alternative languages
Result language
angličtina
Original language name
Phonons and relaxations in unfilled tetragonal tungsten-bronzes
Original language description
The lead-free unfilled tetragonal tungsten-bronzes SBN and CBN had been studied by Raman, infrared and high-frequency dielectric spectroscopies to understand the origin of the phase transition. The substitution in the different channels affects phonon parameters as well as relaxations. Identification of the external modes was done by aid of site group analysis of the structure and respective Raman and IR spectra. It is shown that CBN can show also a small Ca occupancy in the pentagonal channels. Relaxations in SBN show similar qualitative behaviour on increasing Sr content and relaxor behaviour, but for the extreme relaxor samples all frequencies are higher, and the contribution to the permittivity of excitations at GHz-THz range is much stronger. The presence of a soft anharmonic central mode at THz range, and the slowing down of a relaxation at GHz-MHz ranges reveals the coexistence of displacive and order-disorder mechanisms of the phase transition in these materials.
Czech name
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Czech description
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Classification
Type
C - Chapter in a specialist book
CEP classification
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OECD FORD branch
10302 - Condensed matter physics (including formerly solid state physics, supercond.)
Result continuities
Project
<a href="/en/project/GA16-09142S" target="_blank" >GA16-09142S: Lattice dynamics and dielectric response of tetragonal tungsten-bronze oxides</a><br>
Continuities
I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace
Others
Publication year
2021
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Book/collection name
Perovskites and other framework structure crystalline materials: new trends and perspectives
ISBN
979-8583096497
Number of pages of the result
26
Pages from-to
281-306
Number of pages of the book
821
Publisher name
Collaborating Academics
Place of publication
Frontignan
UT code for WoS chapter
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