Dielectric properties and modulus behavior of La0.67Sr0.16Ca0.17MnO3 ceramic prepared by solid state reaction

We have investigated the dielectric properties of La0.67
Sr0.16Ca0.17MnO3
(LSCMO) perovskite synthesized by the solid-state reaction method.
X-ray diffraction analysis revealed that this sample crystallizes in the
distorted rhombohedral system with R
3c 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
′ ≈10
4
) 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
−