Bi2Fe4O9 as a Potential Candidate for Multiple State Memory and Magnetic Field Sensor Application

Abstract

Phase pure polycrystalline Bi2Fe4O9 is prepared using the conventional solid state reaction route. X-ray diffraction (XRD) reveals Bi2Fe4O9 to possess an orthorhombic crystal structure with space group ‘Pbam’. Optical characterization confirms Bi2Fe4O9 to be a direct band gap material with Eg ~ 1.5 eV. Magnetization measurement shows compound to be antiferromagnetic (AFM) with AFM transition temperature ~150 K. The dielectric response of the compound was recorded in the temperature range 10-300 K with the probing frequency from 500 Hz-5 MHz. Here, we report remarkable magnetic field tunable dielectric properties of polycrystalline Bi2Fe4O9 near its AFM transition temperature. Thus, Bi2Fe4O9 can be further stimulated for various other magnetic field sensors, multiple state memory and other ferroelectric applications.