Effect of doping on optical properties in BiMn1−x (TE) x O3 (where x = 0.0, 0.1 and TE = Cr, Fe, Co, Zn) nanoparticles synthesized by microwave and sol-gel methods

Abstract

The structural, optical, and dielectric properties of polycrystalline BiMn1−x TE x O3 (x = 0, 0.1 and TE = Cr, Fe, Co, and Zn) samples synthesized by microwave-assisted synthesis, and sol-gel techniques have been studied. It is found from the XRD data for samples synthesized by both the methods that the lattice volume and average grain size of the prepared samples decrease with doping Cr, Fe, Co, and Zn, consequently. Furthermore, the optical properties obtained from FTIR confirmed that bandgap increases and refractive index decreases on doping transition element in the same order as Cr, Fe, Co, and Zn for samples synthesized by both the methods. The grain sizes obtained for the samples in case of sol-gel method are less than the samples synthesized by microwave method. It is due to less agglomeration of particles in the samples prepared by sol-gel method. P–E loops are measured at room temperature. The variations of dielectric constant and loss tangent with the frequency are plotted. The value of dielectric constant increases for Zn doped sample and then decreases for Cr, Co, and Fe doped samples, respectively. The correlation between the observed structural, optical, and dielectric properties has been described in this paper.