Studies of structural and electrical behaviour of Pb(Mg1/4Zn1/4Mo1/2)O-3 ceramics

Polycrystalline samples of Pb(Mg1/4Zn1/4Mo1/2)O-3 (PMZM) have been prepared by a solid-state reaction technique. Preliminary X-ray studies show the fo rmation of the single-phase PMZM compound with orthorhombic structure. SEM study shows the uniform distribution of spherical grains in the samples. De tailed studies of dielectric constant (epsilon) and loss tangent (tan delta ) are carried out as a function of temperature ( 150-250 degreesC) at 10 kH z and also as a function of frequency (1-10 kHz). Observations of a strong dielectric anomaly as a ferroelectric phase transition at 30 degreesC are s upported by the polarization study. Variation of dc resistivity of the mate rial with temperature shows semiconducting behaviour, usually called NTC (n egative temperature coefficient) resistor.