Enhanced magneto-electric property and Raman spectroscopy of nanocrystalline AlxGa(1−x)FeO3 (x=0.05, 0.10 and 0.20)

Abstract

To enhance the magnetoelectric property of GaFeO3 (GFO), Al3+ doped samples (AlxGa(1−x)FeO3, x=0.05, 0.10 and 0.20) are prepared by the sol-gel technique. Crystallographic phases of the samples are confirmed by X-ray diffractograms. Morphology, average size of nanoparticles including the distribution of sizes are obtained from the results of field emission scanning electron microscopy and high-resolution transmission electron microscopy. Distribution of blocking temperatures and magnetocrystalline anisotropy are determined from the analyses of the observed magnetic hysteresis loops and thermal variation of magnetization curve under zero field cooled and field cooled conditions. Variations of dielectric constant and dielectric loss with frequency show the dispersion in the low frequency region. Ferroelectric orderings have been improved in the doped samples compared to that of GFO. Polarization vs. electric field loops recorded at room temperature indicate that. Magnetic field dependent dielectric constant and negative magneto-capacitance co-efficient of the samples measured at room temperature confirmed that all the samples are multiferroic. Raman spectra and their analyses provide a greater insight into the phase purity and physical properties of the samples. Simultaneous enhancement in magnetic and electric polarizations together with the presence of magneto-electric coupling in the doped samples may enhance the quality of applications in devices.