A brief study on exploration of Ni doped PrFeO3 perovskite as multifunctional material

In this work polycrystalline PrFe1-XNiXO3 (x=0.0, 0.1, 0.2, 0.3) type orthoferrites were synthesized by solid state reaction (SSR) method. The synthesized materials were characterized by X-ray diffraction (XRD), Fourier Transform Infrared (FTIR), Raman, Ultraviolet-Visible (UV-Vis), Photoluminance (PL), dielectric and magnetization techniques. The XRD data were investigated to confirm chemical phase and crystal structure. From this data analysis, it was confirmed that these orthoferrites have orthorhombic structure with p(bnm) symmetry. The Gold smith factor was also calculated for these materials and reveals the distorted structure. Also with Ni doping the average crystallite size and unit cell volumes was found to vary. The crystal symmetry and distortion with doping was further supported by Raman spectroscopy. Here the band observed around 624 cm(-1) (corresponding Fe/Ni-O-6 stretching and breathing) in Raman spectrum clearly shows distortion in the octahedral structure with doping. The FTIR results also confirm variation in metal-oxide bond length associated with mode 519 cm(-1) with Ni substitution in the lattice. For these samples, the maximum optical absorption band in UV-Vis spectra was found at 257 nm. The observed band gap (3.26-2.97 eV) gets blue shifted with Ni doping. Also it was noticed that these bulks samples follow the indirect allowed transitions. Also the PL study carried out on these ceramic samples projects different emission peaks in UV-visible region. The maximum emission peaks were found at around 508 nm followed by three low intensity peaks at around 307 nm, 357 nm, and 411 nm. However after doping there was slight shift in the corresponding emission peaks. A decrease in peak intensity and area with doping was also observed. The variation of dielectric constant (epsilon) and dielectric loss (tan delta) with frequency were also carried out for these samples. A well dispersion in epsilon and tan delta was seen for the understudy materials. From ac conductivity studies, the present samples show ac type conduction. The charge transport takes place by the process of hopping mechanism and follow Jonscher power law behavior. From the magnetic hysteresis studies carried out on these sample shows a weak ferromagnetic behavior followed by exchange bias effect. A possible explanation to these observed properties exhibited by these materials was given and discussed. Based on these properties, the current samples could be used as multifunctional materials.