Open AccessOrigin of terahertz excitations in single-crystalline lead substituted M-type barium hexaferrite doped with Al
Author(s) -
Asmaa Ahmed,
A. S. Prokhorov,
V. B. Anzin,
Д.А. Винник,
А. А. Буш,
B. P. Gorshunov,
Liudmila Alyabyeva
Publication year - 2021
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/1984/1/012015
Subject(s) - terahertz radiation , materials science , terahertz spectroscopy and technology , infrared , dielectric , far infrared , permittivity , phonon , doping , analytical chemistry (journal) , optics , condensed matter physics , physics , optoelectronics , chemistry , chromatography
Single-crystalline lead substituted M-type barium hexaferrites doped with different concentrations of Al 3+ , synthesized by flux technique are investigated at terahertz and infrared frequencies (8-8000 cm −1 ). The spectra of reflection coefficient (R), transmission coefficient (T), complex dielectric permittivity ( ε ` and ε ``) were obtained using terahertz time-domain, and infrared Fourier transform spectrometers over a broadband frequency range 0.24-240 THz and at temperatures 5 K-300 K. The observed absorption lines are assigned to the electronic transitions within the fine-structured ground state of Fe 2+ ions at terahertz frequencies and to optical phonon mode at far-infrared frequencies. To analyze the origin of terahertz excitations in the compounds, we provided a model that accounts for the second-order spin-orbit interactions, the triagonal distortion of the crystal field, and the selection rules of the (C 3v ) point group symmetry of tetrahedral site-position of Fe 2+ .