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High Temperature Dielectric Relaxation in Ferroelectric PbHPO 4 in the kHz Range
Author(s) -
Happ H.,
Wollenburg P.,
Briskot M.,
Spiegelberg M.
Publication year - 1991
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.2221680227
Subject(s) - dielectric , activation energy , arrhenius equation , relaxation (psychology) , atmospheric temperature range , cole–cole equation , ferroelectricity , superposition principle , condensed matter physics , conductivity , materials science , phase (matter) , phase transition , debye , chemistry , nuclear magnetic resonance , thermodynamics , physics , optoelectronics , psychology , social psychology , organic chemistry , quantum mechanics
The complex dielectric constant,\documentclass{article}\pagestyle{empty}\begin{document}$$ \hat \varepsilon $$\end{document} , of PbHPO 4 is measured in the high temperature range of the paraelectric phase between 420 and 590 K at frequencies below 30 kHz. A dielectric response of relaxation type is observed. The real and imaginary part of\documentclass{article}\pagestyle{empty}\begin{document}$$ \hat \varepsilon $$\end{document}take on values of the order of 10 4 at 100 Hz. This response can be well described by a superposition of two Debye‐terms with relaxation times in the millisecond region. Arrhenius plots of the real part of the conductivity show that the crystal passes to a new phase at about 420 K by an activated process with an activation energy of 1.0 eV. This process is assumed to be due to the onset of hindered rotation of HPO 4 groups.