Dielectric properties and modulus behavior of La 0.67 Sr 0.16 Ca 0.17 MnO 3 ceramic prepared by solid state reaction

We have investigated the dielectric properties of La0.67Sr0.16Ca0.17MnO3 (LSCMO) perovskite synthesized by the solid-state reaction method.
X-ray diffraction analysis revealed that this sample crystallizes in the distorted rhombohedral system with R3c space group. Experimental results reveal that the real and imaginary dielectric permittivity (1′ and 1′′), and dielectric loss tangent (tan d) parameters have strong frequency-dependence. The variation of dielectric permittivity and tangent loss (tan d) with frequency show a dispersive behavior at low frequencies and is explained on the basis of the Maxwell–Wagner model and Koop’s theory. It was found that LSCMO ceramics exhibited very high dielectric constant (1′ ≈ 104) values compared to traditional
ferroelectric materials. Electric modulus formalism has been employed to study the relaxation dynamics of charge carriers. The activation energy deduced from analysis of the imaginary part of electric modulus is found to be ∼46.33 meV. The apparent density of sintered pellets were determined using the Archimedes principle. Thus, the value of the density for this compound was 6.155 g.cm−3