A multifunctional transition metal based double perovskite Ba2(FeW)O6: Structural, microstructural, optical, electrical and ferroelectric properties

In this article, synthesis (solid-state reaction) and characterizations (XRD, SEM-EDX, RAMAN, UV–Vis, LCR & P-E measurements) of a polycrystalline double perovskite Ba2(FeW)O6 are reported. The prepared sample crystallizes in tetragonal symmetry with an average crystallite size of 60.7 nm and lattice strain of 0.00045 respectively. Vibrational modes of the molecules in the prepared sample are investigated using Raman spectroscopy. Analysis of scanning electron microscope (SEM) and energy dispersive analysis of x-ray (EDX) supports homogenous distribution of grains and compositional consistency. Optical investigation calibrates direct energy bandgap of 2.72 eV; which may be suitable for photocatalytic and photovoltaic devices. Dielectric, impedance, and modulus spectra have been studied over a wide range of frequencies (1 kHz–1 MHz) and temperatures (25 °C–500 °C). Wide dielectric dispersion at low-frequency encounters space charge polarization with the Maxwell-Wager effect. Study of impedance plots reveals negative temperature coefficient resistance (NTCR) character while existence of non-Debye relaxation mechanism is confirmed from modulus plots. Frequency dependence ac conductivity obeys Jonscher's Power Law (JPL) and confirms the presence of a non-overlapping small polaron and correlated barrier hopping process (CBH). The study of activation energy (Ea), sensitivity factor (α) and thermistor constant (β) values from resistance versus temperature supports NTC thermistor behaviour and explore the possible applications related to temperature-based sensors.