Effect of vanadium doping on structural, dielectric, magnetic, and ferroelectric properties of Ba0.95La0.05TiO3 ceramics

Abstract

The polycrystalline different Ba0.95La0.05Ti1-xVxO3 (where, x = 0.00 to 0.12) ceramics were synthesized using solid-state reaction method. The toroid- and pellet-shaped samples were sintered at 1200°C temperature for 4 h. According to the outcomes of the X-ray diffraction (XRD) investigation, each sample possesses a tetragonal crystal structure that includes a few impurity peaks. Extra Raman modes at 327 cm−1 (for x = 0.06 to 0.12) may be attributed to localized phonon vibrations in the vicinity of a (substitutional) defect or as a result of the relaxation of Raman selection rules due to defect-induced disorder. The density showed a progressive increase as the concentration of V increases, reaching its maximum at the x = 0.06 sample, after which it drops. The x = 0.06 sample displayed the highest bulk density, with a value of ρB = 4.01 g/cm3. Scanning Electron Micrograph (SEM) showed gradual agglomeration of the grain with V-content due to magnetic dipole interaction between one particle and other neighboring particles and exposed the porous nature of the samples. The TEM image demonstrates that the particles are well crystalline. For all of the compositions, the dielectric constant was larger in lower frequency areas and remained constant in higher frequency region. The sample with x = 0.06 showed a maximum dielectric constant of 1140 at 102 Hz. AC conductivity increased with increasing frequency. The Nyquist plot suggested an appearance of grain boundary (bulk) property of the material. The constant value of the real part of complex initial permeability over long range of frequency indicated the magnetic stability of the materials. For ceramics with x = 0.03, the largest real part of the initial permeability of 17.29 is evident. From the M − H loop, at room temperature, feeble ferromagnetism was observed with vanadium substitution in BLT ceramics. It is found that the highest saturation magnetization for the x = 0.03 sample is 2.61 emu/g. For the composition of x = 0.06, the highest polarization of 2.80 μC/cm2 is observed.