Počet záznamů: 1
Perovskites and other framework structure crystalline materials: new trends and perspectives
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SYSNO ASEP 0553887 Druh ASEP M - Kapitola v monografii Zařazení RIV C - Kapitola v knize Název Phonons and relaxations in unfilled tetragonal tungsten-bronzes Tvůrce(i) Buixaderas, Elena (FZU-D) RID, ORCID
Dec, J. (PL)Celkový počet autorů 2 Zdroj.dok. Perovskites and other framework structure crystalline materials: new trends and perspectives. - Frontignan : Collaborating Academics, 2021 / Saint-Gregoire P. ; Smirnov M. - ISBN 979-8583096497 Rozsah stran s. 281-306 Poč.str. 26 s. Poč.str.knihy 821 Forma vydání Tištěná - P Jazyk dok. eng - angličtina Země vyd. FR - Francie Klíč. slova phonons ; relaxations ; IR spectroscopy ; Raman spectroscopy ; dielectric response ; TTBs Vědní obor RIV BM - Fyzika pevných látek a magnetismus Obor OECD Condensed matter physics (including formerly solid state physics, supercond.) CEP GA16-09142S GA ČR - Grantová agentura ČR Institucionální podpora FZU-D - RVO:68378271 DOI 10.23647/ca.md20191227 Anotace 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. Pracoviště Fyzikální ústav Kontakt Kristina Potocká, potocka@fzu.cz, Tel.: 220 318 579 Rok sběru 2022 Elektronická adresa http://perovskitesandotherfws.co-ac.com
Počet záznamů: 1