Dielectric characteristics of cation deficient TbMnO3

Cation deficient polycrystalline Tb1−xMnO3 (x= 0.05, 0.10) and TbMn1−yO3 (y =0.05, 0.10) samples were fabricated by conventional solid-state reaction. The complex dielectric properties of the cation deficient TbMnO3 were investigated as the function of temperature (77 K≤T≤350 K) and frequency (100 Hz≤ f≤ 200 kHz) separately. Compared to the parent TbMnO3, the cation deficient TbMnO3 samples exhibit not only high dielectric constant but also low dissipation factor. Nyquist plots of complex impedance show that the dielectric properties originate from two main relaxation sources, i.e. bulk contributions and grain boundary effects.