Incipient ferroelectricity and conductivity relaxations in Dy2Ti2O7

Dy2Ti2O7 ceramic samples were prepared via the solid-state reaction route. The dielectric properties of the sample were systematically investigated in the temperature range from 4 K to 973 K and the frequency range of 100 Hz to 1 MHz. Both Raman and low-temperature (down to 4 K) dielectric measurements indicate incipient ferroelectricity in the Dy2Ti2O7 sample. In addition, two relaxations were observed in the temperature range above 450 K. Our results indicate that the two relaxations are related to conductivity relaxation associated with singly and doubly ionized oxygen vacancies. (C) 2016 Elsevier B.V. All rights reserved.