Dielectric and impedance spectroscopy of Bi(Ca0.5Ti0.5)O-3 ceramic

Bismuth calcium titanate (BiCa0.5Ti0.5O3) ceramic, fabricated by a ceramic processing technique, has been characterized using a variety of experimental techniques. Analysis of basic crystal structure using X-ray diffraction data exhibits the orthorhombic system. Measurements and detailed analysis of some electrical parameters (i.e.,dielectric constant, loss tangent (energy loss), electrical impedance and modulus, conductivity, etc.) of Bi(Ca0.5Ti0.5)O-3 in a wide range of frequency (10(3)-10(6) Hz) and temperature (30-500 degrees C) have provided some interesting and useful data and results on structure-properties relationship, conduction mechanism, etc.The role of interface, space charge polarization and Maxwell-Wagner dielectric relaxation in getting high dielectric constant of the material at low frequencies and high temperatures has been discussed. Study of temperature dependence of Nyquist plots clearly shows the contributions of grains in resistive and capacitive properties of the material. The frequency of the applied electric field and temperature strongly affect the dielectric (permittivity and dissipation of energy) and electrical (impedance, electrical modulus and conductivity) characteristics of the material.