Effect on structural, optical, electrical, and magnetic properties of Ce and Ni co-doped SmFeO nanostructures

In this study, nano-crystalline powder samples of SmCeFeNiO (0 ≤ x ≤ 0.3; step size = 0.1) have been synthesised via cost-effective sol–gel auto-combustion route and characterised through various analytical techniques to probe the effect of Ce and Ni co-doping on various physical properties of the system under investigation. Rietveld refinement of X-ray diffraction (XRD) patterns along with FTIR spectra elucidates the successful formation of orthorhombic crystal symmetry having Pbnm (D) space group. Williamson–Hall (W–H) analysis has been employed to calculate the average crystallite size and micro-strain induced within the crystal lattice via co-doping. The average particle size evaluated from Transmission electron microscopy (TEM) is concomitant with the W–H findings. UV–Visible spectroscopy corroborates a significant redshift in the energy band-gap from 2.51 to 1.97 eV, whereas there is an increase in the Urbach energy on increasing Ni concentration. Various optical parameters including skin depth, extinction coefficient, and optical conductivity have been realised. SmCeFeNiO exhibits the most prominent ferromagnetic behaviour with remarkably higher values of the magnetisation, coercive field, and remanent magnetisation. In addition, the exchange bias (EB) effect is perceived attributed to the “cluster glass” states for all the samples. DC resistivity data shows typical semi-conducting-like behaviour of all the prepared samples and systematic reduction in the activation energy on the incorporation of Ni ions. The frequency-dependent dielectric measurements divulge the usual dielectric dispersion behaviour. The AC conductivity data obeys the Jonscher power law. Nyquist plots of the studied samples indicate the presence of a non-Debye type of relaxation phenomenon.