Impedance Spectroscopy Analysis of La_0.8Sr_0.2Fe_1-xMg_xO₃ Perovskite Material Prepared by Sol-Gel Method

In this work, the La_0.8Sr_0.2Fe_1-xMg_xO₃ (x = 0.1, 0.2, and 0.3) perovskite materials were effectively prepared using the sol-gel method through the sintering process to form bulk material. XRD analysis revealed that these perovskite materials are well suited to the Pbnm space group and have an orthorhombic structure. With increasing Mg substitution, the lattice parameters and crystallite size increase, indicating that the presence of Mg²⁺ in the crystal lattice inhibits the growth of the crystallite size. By Impedance Spectroscopy method using RLC meter, at room temperature, the electrical properties of the material were determined as a frequency's function (100Hz-7MHz). The conductivity of La_0.8Sr_0.2Fe_1-xMg_xO₃ was contributed by the grains and grain boundaries, according to the Nyquist and Bode plots. Because of the hole carrier, the Nyquist plot of complex impedance increases when Mg is substituted. Real part impedance analysis explains the existence of space charge polarization at low frequency. The semicircle's diameter increases from increasing to doping with magnesium. This means that doping with magnesium will cause the resistance of the material to increase. The impedance data shows that as the Mg content increases, the impedance value decreases. According to dielectric research, dielectric spectroscopy shows that as Mg doping increases, the dielectric loss increases and the dielectric constant (ε') of samples decreases at a lower frequency.