Effect of particles size on magnetodielectric, magnetoimpedance and electrical properties of LaFeO₃ nanoparticles

Effect of particles size on the behavior of magnetoimpedance, magnetodielectric and detailed electrical properties of structural characterized LaFeO₃ nanoparticles prepared through chemical ‘pyrophoric reaction’ technique having particles size of ~ 21, 43 and 51 nm have investigated. Dielectric constant of these nanoparticles gives the evidence of space charge polarization in the sample at lower frequency regime. Maximum magnetodielectric effect is obtained to ~ 61% at room temperature for particle size of ~ 21 nm, which may be due to the large surface to volume ratio of this nanoparticles compared to other particles size attributing the enhancement of space charge polarization. The maximum value of magnetoimpedance is found to ~ 92% for ~ 21 nm nanoparticle at room temperature. Magnetic field and frequency dependence room temperature magnetoimpedance are decreased with particles size of the nanoparticles. This behaviour has been explained through the light of classical electrodynamics, which reveals that this effect is depending on the magnetic field and ac signal frequency. Impedance spectroscopy is employed to study the electrical transport properties of the samples considering an equivalent circuit model for the effect of nanometric grain size. The electrical relaxation process of these materials is temperature dependent. Furthermore, ac conductivity curves follow the Jonscher’s power law for electrical conduction process of the system through polaronic hopping.