Polar soft mode in titanium-doped single crystalline BaFe12-xTix019 M-type hexaferrite

Abstract

Electrodynamic response of single-crystalline M-type barium hexaferrite doped with $\mathbf{Ti}^{4+}$ is studied for two principal polarizations in the temperature range 10–300 K by means of terahertz-infrared spectroscopy. The dynamics of polar phonons is investigated along with low-energy absorption mechanisms connected with relaxation process in polar domain walls and with anharmonic contributions of multiple phonons interaction.