Volume 107, Number 1, July 2014
|Number of page(s)||5|
|Section||Condensed Matter: Electronic Structure, Electrical, Magnetic and Optical Properties|
|Published online||04 July 2014|
Negative electrocaloric effect in antiferroelectric PbZrO3
1 Jožef Stefan Institute - Jamova 39, 1001 Ljubljana, Slovenia
2 Jožef Stefan Postgraduate School - Jamova 39, 1000 Ljubljana, Slovenia
Received: 13 May 2014
Accepted: 11 June 2014
The dielectric and thermal properties of a typical antiferroelectric (AFE) material are investigated by minimising numerically the free energy as given by the Kittel model of AFEs. The phase line of second-order phase transitions in the phase diagram is shown to change to a first-order line at the tricritical point T3cp, E3cp. The static dielectric susceptibility and the electrocaloric (EC) effect are calculated as a function of temperature and the applied electric field E. It is found that in a given range of electric fields and temperatures the EC effect has negative values but generally becomes positive above the AFE ordering temperature T0. The dielectric susceptibility shows characteristic peaks at the phase transitions between the field-induced polar and the AFE antipolar phase, and diverges at the tricritical point. We present experimental results for a negative EC effect, which have been obtained by direct EC measurements in PbZrO3 ceramics, and agree qualitatively with the above model.
PACS: 77.70.+a – Pyroelectric and electrocaloric effects / 77.84.-s – Dielectric, piezoelectric, ferroelectric, and antiferroelectric materials / 65.40.G- – Other thermodynamical quantities
© EPLA, 2014
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.