DIFFUSE PHASE-TRANSITION IN SOLID-SOLUTION OF PB (MG1 4ZN1/4NB1/2)O3-DELTA AND PBTIO3/

Solid solutions of Pb(Mg1/4Zn1/4Nb1/2)O3-delta and PbTiO3, viz, cerami cs of the general composition Pb(Mg1/4Zn1/4Nb1/2)1-xTixO3 (where x = 0 , 0.05, 0.1, 0.2 and 0.3 etc.) were prepared by high-temperature solid -state reaction. Structural phase present in the prepared materials wa s identified by the X-ray powder diffraction technique to be of a sing le cubic perovskite type. Increased addition of PbTiO3 was found to ca use a small shift in the characteristic reflections of the perovskite pattern. Transition temperature and diffuseness of transition of the m aterial were found to increase with the increase in the amount of PbTi O3. High dielectric constant at ferroelectric transition temperature ( T(C)) close to room temperature was found to be realizable at less tha n 5% of PbTiO3 for the solution.