scispace - formally typeset
Journal ArticleDOI

Lattice anharmonicity and polar soft mode in ferrimagnetic M-type hexaferrite BaFe12O19 single crystal

Reads0
Chats0
TLDR
In this article, the polar phonon modes in BaFe12O19 single crystal were studied in the temperature range from 6 to 300 K by polarized infrared spectroscopy, and it was shown that the phonon spectrum of the crystal is strongly anharmonic and unstable with respect to long-wavelength fluctuations of the dielectric permittivity along the hexagonal axis.
Abstract
The polar phonon modes in BaFe12O19 single crystal are studied in the temperature range from 6 to 300 K by polarized infrared spectroscopy. The phonon spectrum of the crystal is strongly anharmonic and unstable with respect to long-wavelength fluctuations of the dielectric permittivity along the hexagonal axis. Our results suggests that in BaFe12O19 hexaferrite symmetry lowering to the polar phase with the space group P63 mc can be expected.

read more

Citations
More filters
Journal ArticleDOI

Polarization origin and iron positions in indium doped barium hexaferrites

TL;DR: In this article, structural and magnetic parameters were determined including the unit cell parameters, ionic coordinates, thermal isotropic factors, occupation positions, bond lengths and bond angles, microstrain values and magnetic moments.
Journal ArticleDOI

Thermal evolution of exchange interactions in lightly doped barium hexaferrites

TL;DR: In this paper, the effect of light diamagnetic doping on the nature of indirect exchange interactions with temperature increase has been discussed, and the light-diamagnetic doping mechanism and magnetic structure model are proposed.
References
More filters
Journal ArticleDOI

Hexagonal ferrites: A review of the synthesis, properties and applications of hexaferrite ceramics

TL;DR: The most important members of the hexaferrite family are shown below, where Me = a small 2+ ion such as cobalt, nickel, or zinc, and Ba can be substituted by Sr: • M-type ferrites, such as BaFe12O19 (BaM or barium ferrite), SrFe 12O19(SrM or strontium ferite), and cobalt-titanium substituted M ferrite, Sr- or BaFe 12−2xCoxTixO19, or CoTiM as discussed by the authors.
Journal ArticleDOI

Anharmonic effects in light scattering due to optical phonons in silicon

TL;DR: In this paper, light scattering of the linewidth and frequency shift of the optical phonon in silicon over the temperature range of 5-1400 K are presented. But they do not consider the four-phonon anharmonic processes.
Journal ArticleDOI

Crystal stability and the theory of ferroelectricity

W. Cochran
- 01 Oct 1960 - 
TL;DR: In this article, it is shown that the parameters which determine the lattice vibrations of a diatomic ionic crystal may be chosen in such a way that the crystal will exhibit ferroelectric properties, and that anti-ferroelectric transitions may be regarded as the result of an instability of the crystal for a certain normal mode of vibration.
Journal ArticleDOI

Anharmonic Decay of Optical Phonons

TL;DR: In this article, an expression for the lifetime of an optical phonon decaying into two acoustical phonons, and its temperature dependence, was derived from perturbation theory, and the strength of the interaction was expressed in terms of the Gruneisen constant and the effect of a strain, equivalent to the instantaneous strain of a optical mode on the frequency spectrum of a linear chain with alternating force constants.
Journal ArticleDOI

Recent advances in processing and applications of microwave ferrites

TL;DR: In this article, a review of recent advances in the processing of microwave ferrites is presented, including self-bias magnetization, tunability of the magnetic anisotropy, low microwave loss, and volumetric and weight reduction.
Related Papers (5)