Maxwell-Wagner polarization mechanism in potassium and titanium doped nickel oxide showing giant dielectric permittivity

KxTiyNi1-x-yO ( x = 0.05-0.3, y = 0.02-0.25) ceramics ( abbreviated as KTNO) have been synthesized showing high permittivity. All the KTNO samples of varying compositions exhibit high dielectric permittivity (similar to 10(4)) near room temperature, which is comparable to that of the recently discovered CaCu3Ti4O12 ( CCTO) ceramic. The high dielectric constant of KTNO depends on both the K and Ti content and can be attributed to the Maxwell-Wagner polarization mechanism and to a thermally activated mechanism.