Dielectric properties of Sn-substituted lead calcium iron niobate

Sn-substituted lead calcium iron niobate with general formula (Pb0.45Ca0.55)(Fe0.5Nb0.5)1−ySnyO3 and 0.00 ≤ y ≤ 0.15 in the steps of 0.03 were synthesized by using columbite precursor method. XRD spectra from these ceramics reveal a perovskite structure with pseudocubic symmetry. Small amount of pyrochlore phase was obtained decreasing with increasing Sn content up to y = 0.09. The degree of perovskite phase formation and average grain size increased with increase in Sn contents. Dielectric properties were measured in the frequency range 200 kHz to 10 MHz at room temperature and a high relative permittivity of 71.38 and loss tangent of 0.0081 at 10 MHz along with low temperature coefficient of resonant frequency of +7.665 ppm/K for y = 0.09 has been obtained. Obtained results have shown that the substitution of (Fe0.5Nb0.5)4+ by Sn4+ at B-site improves the dielectric properties by reducing the loss tangent and temperature coefficient of resonant frequency. The studied materials are promising candidate for multilayer capacitors, resonators, and filters.