Dielectric Response of KTaO3 Single Crystals Weakly Co-Doped with Li and Mn

Abstract

Alkali tantalates are encouraging functional materials with versatile properties that make them potential players in microelectronics, photocatalytic processes or medicine. Here, KTaO3 single crystals with 0.27% Li and 0.15% or 0.31% Mn contents determined by inductively coupled plasma spectroscopy analysis are studied at low temperatures using dielectric spectroscopy in a frequency range of 102–106 Hz. Both Li and Mn doping are found to induce separate low-frequency dielectric relaxations of comparable strength in KTaO3. The relaxation dynamics follow the Arrhenius law with activation energy values of ~77 and 107 meV, attributing the relaxation origin to the dipoles formed by off-centre Li+K and Mn2+K ions, respectively.