Premium
Millimetre‐wave investigation of the soft mode in ferroelectric PbHPO 4
Author(s) -
Briskot M.,
Happ H.
Publication year - 1992
Publication title -
annalen der physik
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.009
H-Index - 68
eISSN - 1521-3889
pISSN - 0003-3804
DOI - 10.1002/andp.19925040603
Subject(s) - ferroelectricity , dielectric , condensed matter physics , soft modes , relaxation (psychology) , quantum tunnelling , proton , materials science , phase transition , debye , reflection (computer programming) , phase (matter) , physics , optoelectronics , quantum mechanics , psychology , social psychology , computer science , programming language
The complex dielectric function along the a axis of PbHPO 4 single crystals is determined from reflection measurements at frequencies between 70 and 225 GHz in the paraelectric and the ferroelectric phase near the transition temperature T c = 310 K. The data are complemented by a remeasurement of the properties of the lowest far‐infrared mode. The mm‐wave data can be described by a simple Debye formula. The relaxation time exhibits critical slowing down, and the corresponding relaxation frequency varies between about 2 and 60 GHz near T c . Proton tunneling appears to play no essential role in this dielectric mechanism related to proton ordering.