New nanoparticulate Gd1-xZrxFe1-yMnyO3 multiferroics: Synthesis, characterization and evaluation of electrical, dielectric and magnetic parameters

Nanoparticles of Gd1-xZrxFe1-yMnyO3 (x, y = 0-1) were synthesized by micro-emulsion method. The structural elucidation was accomplished by X-ray diffraction (XRD), Fourier transformed infrared spectroscopy, scanning electron microscopy (SEM) and thermogravimetric analysis that confirmed that all the nanoparticles are crystalline in orthorhombic phase. The particles size was found in the range 12-48 nm (determined by XRD) and 33-48 nm (estimated by SEM). The nanoparticles were then evaluated for electrical, dielectric and magnetic properties. The electrical resistivity studies exhibited the transition between metal to semiconductor in the range 340-380 K, besides overall electrical resistivity was decreased with the increased Zr-Mn contents. The maximum electrical resistivity (80.95 x 10(8) Omega cm) was exhibited by Gd0.75Zr0.25Fe0.75Mn0.25O3 nanoparticles. The dielectric behavior was found to increase with increased Zr-Mn contents. The magnetic behavior confirmed the transition of magnetic order from antiferromagnetic to the ferromagnetic as the Zr and Mn contents were increased. The new structurally stable nanostructured multiferroics can be utilized for fabricating high frequency and magnetic recording devices. (C) 2013 Elsevier B. V. All rights reserved.