Structural and functional properties of sol-gel synthesized and microwave heated Pb0.8 Co0.2-zLazTiO3 (z = 0.05–0.2) nanoparticles

Abstract

The present work reports the effect of La-substitution on structural and functional properties of lead cobalt titanate (PCT) perovskite structure as a function of variation of Co-content. The sol-gel synthesized and microwave heated Pb0.8 Co0.2-zLazTiO3 (z = 0.05, 0.1, 0.15 & 0.2) (PCLT) nanoparticles showed the presence of complete cubic phases while few were noted to be tetragonal lead titanate (PT) phases. The surface morphology was examined by field emission scanning electron microscope (FESEM) and high resolution transmission electron microscope (HRTEM). The HRTEM revealed fibers like nanoparticles at z = 0.15 and 0.2. The Fourier transform infrared spectra attributed the presence of metal oxide bonds. Furthermore, the wide optical band gap energy (Eop) was acquired to be changing from 2.32 to 3.20 eV. In addition, the electrical parameters such as dielectric constant (ε'), dielectric loss (ε"), ac & dc-electrical conductivity (σac & σdc), complex dielectric modulus (M*) and complex impedance (Z*) were studied as a function of frequency (f) and composition. Using power law fitting, the σdc values were determined. The z = 0.15 content exhibited high σdc of ~ 2.51 × 10−7 S/cm among all compositions. Besides, the results expressed the existence of short range and long range hopping conduction regions in dielectric modulus spectra. The Nyquist plots were drawn to elucidate the electrical conduction and relaxation mechanism. Later on, ferroelectric hysteresis loops were recorded for z = 0.05–0.2.