Расчет динамики решетки кристаллов RFe-=SUB=-3-=/SUB=-(BO-=SUB=-3-=/SUB=-)-=SUB=-4-=/SUB=- в квазигармоническом приближении
Author(s) -
М.С. Павловский,
Н.Д. Андрюшин
Publication year - 2019
Publication title -
физика твердого тела
Language(s) - English
Resource type - Journals
eISSN - 1726-7498
pISSN - 0367-3294
DOI - 10.21883/ftt.2019.11.48407.486
Subject(s) - phonon , brillouin zone , lattice (music) , soft modes , phase boundary , phase transition , condensed matter physics , materials science , phase (matter) , chemistry , physics , optoelectronics , organic chemistry , acoustics , dielectric , ferroelectricity
The lattice dynamic calculations and calculation of temperature dependence of the vibrational frequencies in the quasi-harmonic approximation were carried out for RFe3(BO3)4 crystals (R = Pr, Nd, Tb, Dy, Ho) in high temperature phase R32. It was obtained that in the boundary point Λ of Brillouin zone the frequency of instable vibrational mode, which associated with structural phase transition R32 -> P3121, change intensely with temperature in TbFe3(BO3)4, DyFe3(BO3)4 and HoFe3(BO3)4 crystals. The frequency of “soft” mode stabilizes with temperature increasing and takes a real value. Significant changes in phonon spectra, including in the boundary point Λ, in PrFe3(BO3)4 and NdFe3(BO3)4 crystals with temperature increasing were not observed.
Accelerating Research
Robert Robinson Avenue,
Oxford Science Park, Oxford
OX4 4GP, United Kingdom
Address
John Eccles HouseRobert Robinson Avenue,
Oxford Science Park, Oxford
OX4 4GP, United Kingdom