https://doi.org/10.1140/epjb/e2014-50329-4
Regular Article
Lattice anharmonicity and polar soft mode in ferrimagnetic M-type hexaferrite BaFe12O19 single crystal
1
Faculty of Physics, Southern Federal University,
344006
Rostov on Don,
Russia
2
Moscow Institute of Physics and Technology (State
University), Dolgoprudny, 141700
Moscow Region,
Russia
3
A.M. Prokhorov General Physics Institute, Russian Academy of
Sciences, 119991
Moscow,
Russia
4
1. Physikalisches Institut, Universität Stuttgart,
70550
Stuttgart,
Germany
5
Moscow State Technical University of Radio engineering,
Electronics and Automation, 119454
Russia
a e-mail: a.mikheykin@sfedu.ru
Received:
22
May
2014
Received in final form:
29
June
2014
Published online:
15
October
2014
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 P63mc can be expected.
Key words: Solid State and Materials
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2014