Ferroelectric Relaxor Quantum Crystals
| Autor: | James F. Scott |
|---|---|
| Přispěvatelé: | EPSRC, University of St Andrews. School of Chemistry, University of St Andrews. School of Physics and Astronomy, University of St Andrews. Condensed Matter Physics |
| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
Materials science
General Chemical Engineering TK Electric susceptibility T-NDAS 02 engineering and technology quantum critical points Vogel-Fulcher relaxor 01 natural sciences Isothermal process TK Electrical engineering. Electronics Nuclear engineering Inorganic Chemistry Condensed Matter::Materials Science 0103 physical sciences lcsh:QD901-999 General Materials Science Diffusion (business) 010306 general physics Absolute zero Quantum Quantum tunnelling QC Relaxor Condensed matter physics Quantum critical points 021001 nanoscience & nanotechnology Condensed Matter Physics Ferroelectricity Domain wall (magnetism) QC Physics lcsh:Crystallography 0210 nano-technology |
| Zdroj: | Crystals, Vol 8, Iss 4, p 180 (2018) Crystals; Volume 8; Issue 4; Pages: 180 |
| ISSN: | 2073-4352 |
| Popis: | Funding: UK EPSRC grant EP/P024637/1. A discussion is given of ferroelectrics (FEs) that have their Curie temperatures Tc very near absolute zero. These have differences in their dynamics in comparison with higher-temperature systems, since domain wall motion occurs via quantum mechanical tunneling and not by thermally activated diffusion. Emphasis in the present paper is on FEs that have relaxor characteristics. In such systems the temperature at which the isothermal electric susceptibility ε(T,f) peaks is a strong function of frequency, decreasing with decreasing frequency. This is due to glassy viscosity and is symbolic of non-equilibrium dynamics, usually described by a Vogel-Fulcher equation. It permits an extra dimension over which to examine the transitions. The second half of this paper reviews domain wall instabilities and asks about their presence in QCP ferroelectrics, which has not yet been reported and may be unobservable due to the absence of thermal diffusion of walls near T=0; in this respect we note that diffusion does exist in ferroelectric relaxors even at T=0, by virtue of their glassy, viscous dynamics. Publisher PDF |
| Databáze: | OpenAIRE |
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