Studies of Dielectric Permittivity of Y<sub>2</sub>NiMnO<sub>6</sub> Ceramics for DC Bias at Various Temperatures

Abstract

The dielectric permittivity (ε) of Y2NiMnO6 ceramics prepared by sintering at 1400 °C over 6 to 24 hours was investigated. The response of the ceramics was measured from 1 kHz to 3 MHz, with the influence of a fixed dc bias from 0 to 1.5 V and temperature from 40 °C to -60 oC. Increasing dc bias was found to reduce ε' at low frequencies, while at higher frequencies the dc bias had less influence on ε'. At 40 °C a sharp transition from high to low ε' occurred starting at ~100 kHz, as the temperature of the ceramic was lowered, the transition shifted to lower frequencies. This behaviour is attributed to the charge ordering of Ni2+ and Mn4+ ions and the thermal effect on the ions energy.