Počet záznamů: 1
Studies of relaxor ferroelectrics with spontaneous polar nanoregions
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SYSNO ASEP 0485831 Druh ASEP D - Dizertace Zařazení RIV Záznam nebyl označen do RIV Název Studies of relaxor ferroelectrics with spontaneous polar nanoregions Tvůrce(i) Ondrejkovič, Petr (FZU-D) RID, ORCID Celkový počet autorů 1 Vyd. údaje Praha: Univerzita Karlova, 2017 Poč.str. 128 s. Forma vydání Tištěná - P Jazyk dok. eng - angličtina Země vyd. CZ - Česká republika Klíč. slova relaxor ferroelectrics ; strontium barium niobate ; inelastic neutron scattering ; phase-field simulations 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 GA15-04121S GA ČR - Grantová agentura ČR Institucionální podpora FZU-D - RVO:68378271 Anotace The thesis is devoted to relaxor ferroelectrics with spontaneous polar nanoregions. We have investigated one of the canonical representatives, uniaxial strontium barium niobate, by means of neutron scattering, and also performed computer simulations with a model of a uniaxial ferroelectric with point defects. Neutron scattering studies of strontium barium niobate single crystals elucidate diffuse scattering which is associated mainly with the static ferroelectric nanodomain structure and dynamic order-parameter (polarization) fluctuations. Moreover, high-resolution neutron backscattering experiments allowed us to resolve characteristic frequencies of the order-parameter fluctuations and prove that this component is caused by the same polar fluctuations that are responsible for the Vogel-Fulcher dielectric relaxation. The model system with point defects exhibits relaxor-like physical properties which are associated with a distribution of crossover temperatures.
Pracoviště Fyzikální ústav Kontakt Kristina Potocká, potocka@fzu.cz, Tel.: 220 318 579 Rok sběru 2018
Počet záznamů: 1