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Low‐Frequency Lattice Dynamics of NaNO 2 Crystals
Author(s) -
Kozlov G. V.,
Kryukova E. B.,
Wyncke B.,
Brehat F.,
Sherif M. E.
Publication year - 1985
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.2221270205
Subject(s) - ferroelectricity , soft modes , anharmonicity , dielectric , phonon , materials science , excitation , spectroscopy , condensed matter physics , crystal (programming language) , relaxation (psychology) , phase transition , nano , molecular physics , optics , chemistry , optoelectronics , physics , composite material , programming language , psychology , social psychology , quantum mechanics , computer science
Submillimeter monochromatic BWT spectroscopy (3 to 33 cm −1 ) and far infrared reflection spectroscopy (40 to 600 cm −1 ) are used to investigate the low‐frequency dynamics of the classical ferroelectric NaNO 2 of the order‐disorder type in the temperature interval 20 to 210 °C in the ferro‐ and paraelectric phase. In the submillimeter dielectric spectra ε ★ ( v , T ) of the NaNO 2 crystal, together with the previously observed radiofrequency mode and the optical phonon 180 cm −1 , low‐frequency anharmonic excitation subsidiary to the soft mode is recorded at the intermediate frequency 33 cm −1 , Analysing the temperature behaviour of the parameters of this apparently relaxation excitation it is possible to assume that it is directly associated with the process of ferroactive crystal subsystem disordering at the ferroelectric phase transition.