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Anomalous dielectric and thermal properties of Ba-doped PbZrO3 ceramics

Pirc, R. and Rožič, B. and Koruza, Jurij and Malič, Barbara and Kutnjak, Z. (2015):
Anomalous dielectric and thermal properties of Ba-doped PbZrO3 ceramics.
In: Journal of Physics: Condensed Matter, IOP Publishing, 27, ISSN 0953-8984, [Online-Edition: http://iopscience.iop.org/0953-8984/27/45/455902],
[Article]

Abstract

The dielectric and thermal properties of an antiferroelectric (AFE) material characterised by an intermediate ferroelectric (FE) phase between the AFE and paraelectric phase in zero field are studied by means of a generalised Landau–Kittel model of AFEs. A temperature-dependent coupling of the two sublattices is introduced in accordance with the Rae–Dove (RD) model of re-entrant phase transitions. The sublattice polarisation components are calculated as functions of temperature and the applied electric field by minimising numerically the free energy. The calculated dielectric susceptibility shows anomalies at the boundaries of the intermediate FE phase, characteristic for first-order phase transitions. It is shown that this behaviour is in qualitative agreement with the measured dielectric constant in Ba-doped PbZrO3 ceramics.The model also predicts a negative adiabatic electrocaloric temperature change ∆T in a broad temperature range in the AFE phase, in qualitative agreement with experiments. The dipolar heat capacity is also predicted to be negative in the intermediate phase in zero field, in analogy with the results of the RD model.

Item Type: Article
Erschienen: 2015
Creators: Pirc, R. and Rožič, B. and Koruza, Jurij and Malič, Barbara and Kutnjak, Z.
Title: Anomalous dielectric and thermal properties of Ba-doped PbZrO3 ceramics
Language: English
Abstract:

The dielectric and thermal properties of an antiferroelectric (AFE) material characterised by an intermediate ferroelectric (FE) phase between the AFE and paraelectric phase in zero field are studied by means of a generalised Landau–Kittel model of AFEs. A temperature-dependent coupling of the two sublattices is introduced in accordance with the Rae–Dove (RD) model of re-entrant phase transitions. The sublattice polarisation components are calculated as functions of temperature and the applied electric field by minimising numerically the free energy. The calculated dielectric susceptibility shows anomalies at the boundaries of the intermediate FE phase, characteristic for first-order phase transitions. It is shown that this behaviour is in qualitative agreement with the measured dielectric constant in Ba-doped PbZrO3 ceramics.The model also predicts a negative adiabatic electrocaloric temperature change ∆T in a broad temperature range in the AFE phase, in qualitative agreement with experiments. The dipolar heat capacity is also predicted to be negative in the intermediate phase in zero field, in analogy with the results of the RD model.

Journal or Publication Title: Journal of Physics: Condensed Matter
Volume: 27
Publisher: IOP Publishing
Uncontrolled Keywords: antiferroelectrics, phase transitions, electrocaloric effect
Divisions: 11 Department of Materials and Earth Sciences
11 Department of Materials and Earth Sciences > Material Science
11 Department of Materials and Earth Sciences > Material Science > Nonmetallic-Inorganic Materials
Date Deposited: 23 Oct 2015 09:43
Official URL: http://iopscience.iop.org/0953-8984/27/45/455902
Identification Number: doi:10.1088/0953-8984/27/45/455902
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