Comprehensive studies of impedance spectroscopy, Raman, infrared, and ferroelectric properties of BiFeWO6 and application

Abstract

A tetragonal double perovskite BiFeWO₆ nanopowder was successfully synthesized via the solid-state reaction technique. Structural characterization using X-ray diffraction (XRD) revealed an average crystallite size of 11.6 nm with a lattice strain of 0.06499. Optical properties were investigated through ultraviolet (UV) visible spectroscopy, which determined a bandgap energy of 1.41 eV, highlighting its potential for photovoltaic applications. Raman spectroscopy confirms the presence of all constituent elemental vibrational modes associated with various molecular bonding interactions in the studied material. Dielectric analysis exhibits a Maxwell-Wagner-type polarization effect and promises to be a material with a high dielectric constant and low loss for energy storage devices. The study of impedance plots reveals the negative temperature coefficient of resistance (NTCR) behavior, whereas the electrical modulus study suggests the presence of a non-Debye-type relaxation mechanism. The study of AC conductivity versus frequency and temperature reveals the fact that the conduction mechanism is controlled by the thermally activated charge carriers. Again, semicircular Nyquist and Cole-Cole plots confirm the semiconductor nature and well-supported impedance results. The study of resistance versus temperature shows the NTC thermistor character and became one strong candidate for temperature sensor devices.