Critical behaviour of Sn2P2S6and Sn2P2(Se0.28S0.72)6crystals under high hydrostatic pressures
| Autor: | Rostyslav Vlokh, Bohdan Zapeka, I. Martynyuk-Lototska, M. Kostyrko |
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| Rok vydání: | 2015 |
| Předmět: |
Condensed Matter - Materials Science
Phase transition Materials science Birefringence Strongly Correlated Electrons (cond-mat.str-el) Condensed matter physics Hydrostatic pressure Diagram Materials Science (cond-mat.mtrl-sci) FOS: Physical sciences Condensed Matter Physics law.invention Condensed Matter - Strongly Correlated Electrons Character (mathematics) Tricritical point law Hydrostatic equilibrium |
| Zdroj: | Philosophical Magazine. 95:382-393 |
| ISSN: | 1478-6443 1478-6435 |
| DOI: | 10.1080/14786435.2015.1006295 |
| Popis: | Basing on the temperature dependences of optical birefringence for Sn2P2S6 and Sn2P2(Se0.28S0.72)6 crystals subjected to hydrostatic pressures, we prove unambiguously that Sn2P2S6 reveals a tricritical point on its (p,T)-phase diagram with the coordinates (p,T) = (4.3 kbar, 259 K), so that the second-order phase transition transforms into the first-order one whenever the pressure increases above 4.3 kbar. We also find that increasing hydrostatic pressure applied to Sn2P2(Se0.28S0.72)6 leads to the change in the phase transition character from tricritical to first-order. Further increase in the pressure up to ~ 2.5 kbar imposes splitting of the first-order paraelectric-to-feroelectric phase transition into two phase transitions, a second-order paraelectric-to-incommensurate one and a first-order incommensurate-to-ferroelectric transition. Comment: 13 pages, 7 figures |
| Databáze: | OpenAIRE |
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