Dielectric properties of Y and Nb co-doped TiO2 ceramics

In this work, the (Y0.5Nb0.5)(x)Ti1-xO2 (x = 0.001, 0.01, 0.02, 0.04, 0.06 and 0.1) ceramics (as called YNTO) were fabricated by synthesized through a standard solid-state reaction. As revealed by the X-ray diffraction (XRD) spectra, the YNTOs exhibit tetragonal rutile structure. Meanwhile, the grain size of YNTO ceramics increased and then decreased with the increase of x value, and the largest value reached when x = 0.02. All the YNTO samples display colossal permittivity (similar to 10(2)-10(5)) over a wide temperature and frequency range. Moreover, the optimal ceramic, (Y0.5Nb0.5)(0.02)Ti0.98O2, exhibits high performance over a broad temperature range from 20 degrees C to 180 degrees C; specifically, at 1 kHz, the dielectric constant and dielectric loss are 6.55 x 10(4) and 0.22 at room temperature, and they are 1.03 x 10(5) and 0.11 at 180 degrees C, respectively.