Complex impedance spectroscopy, dielectric response, and magnetic properties of the La0.7 Sr0.3BO3 (B = Mn, Fe, Co, or Ni) perovskite oxides

Abstract

The perovskite materials (La0.7Sr0.3BO3, B= Ni, Co, Fe, or Mn), in the present study, have successfully been prepared, using the co-precipitation method. X-ray diffraction data confirmed the multiphase structures in all synthesized samples except in lanthanum strontium ferrite. With the help of the Williamson-Hall method, based on the uniform deformation model, the strain and crystallite size of the synthesized samples have been calculated. The maximum crystallite size and minimum strain are observed in the lanthanum strontium ferrite sample. In addition, the obtained structural data help us to calculate the texture coefficient. Field emission scanning electron microscope images prove the formation of the nano-scaled particles. Moreover, the energy-dispersive X-ray analysis confirm the formation of lanthanum strontium-based perovskites that are synthesized in this project. Fourier transform infrared spectroscopy spectra represent the metal-oxide bonds in the 495 cm−1, 592 cm−1, 577 cm−1, and 622 cm−1 for LSNO, LSCO, LSFO, and LSMO, respectively. The examination of the dielectric properties of synthesized nanoparticles at room temperature has been conducted in great details across a range of frequency range of 10−3 Hz to 1 MHz. The capacitance of all samples demonstrates an increase as frequency decreases. Moreover, the obtained results validate that the dielectric parameters exhibit an increase with frequency decreasing for all samples. The outcomes of the Modulus exhibit an increase in the vicinity of high frequencies, whereas the magnitudes of the Modulus tend to converge toward zero in the proximity of low frequencies. Contrary to the effect of nickel, cobalt, or Iron substitution for manganese in dielectric parameters values, the magnetic parameters, denoted by μ′andμ″, of lanthanum strontium manganite prove to be smaller than the magnetic parameters of other synthesized samples. A VSM at room temperature reveal the LSMO and LSCO samples to be paramagnetic and the LSFO and LSNO samples to be ferromagnetic.