Modulation of electric and magnetic ordering in GdFeO3 orthoferrites system by Ce-doping

Abstract

In the present attempt, orthoferrites system GdFeO3 (GFO) is modified by partially substituting Gd by Ce and its influence on structure, electric and magnetic orderings of GFO are systematically explored. The doped-GFO systems with various compositions Gd1-xCexFeO3 (GCFO; x = 0 ≤ x ≤ 0.1 with 0.02 interval) are developed by using sol-gel combustion route. The Rietveld refinements of the XRD data confirm orthorhombic phase with Pbnm space group of all compositions. The substitutional effect of Gd by Ce in GFO is found to reduce Dielectric constant and to enhance dissipation factor. Both these effect is associated with change in hybridization between O-2p states and Fe-3d due to change in Fe–O bond length by dopant effect. The dielectric relaxation are revealed using impedance loss spectra and electric modulus formalism in the frequency range 1 Hz to 1 MHz and in the temperature rage 200–450 °C and relaxation time is found to decrease with doping level and temperature. The net resistivity of GFO is reduced with increase in conductivity by around two orders by Ce-doping. The frequency dependence of conductivity follows the power law. The activation energy for dielectric relaxation in GCFO is varying between 0.3 and 0.5 eV at grain boundaries; while 0.25–0.4 eV on grain, indicate the conduction mechanism on grain boundaries is attributed by oxygen vacancies defect and grains by polaron hopping. The magnetization study displays doping of Ce modifies the M-H hysteresis loop and gives canted antiferromagnetic behavior in GFO. The remnant magnetization and coercivity is suddenly jumped by two order in GCFO system. The significant enhancement in electric and magnetic orderings is achieved by Ce addition in GFO.