Structural, dielectric, electric, transport, and optical properties of a double perovskite: BaKFeMoO6

In this communication, synthesis (solid-state reaction) and characterization (XRD, SEM, EDAX, RAMAN, UV & LCR) of a double perovskite BaKFeMoO6 (BKFMO) are reported. Monoclinic crystal symmetry with average crystallite size and lattice strain are evaluated as 55 nm and 0.00254 respectively from XRD data. A scanning electron microscope (SEM) study reveals the uniform distribution of grains through well-defined grain boundaries and also discusses their role in the conduction mechanism. Purity and compositional analysis confirm the presence of all constituent elements in both weight and atomic percentage from energy dispersive x-ray analysis (EDAX). The incorporation of the K+ and Fe3+ in the Ba-and Mo-site in the host BaMoO4 is confirmed by Raman's study. Ultraviolet-visible (UV) data calibrate an energy bandgap of 2.9 eV; which may be suitable for photovoltaic applications. The measurement and analysis of dielectric, ac conductivity, and impedance are carried out in a wide range of frequencies (1 kHz-1 MHz) and temperatures (25 degrees C - 500 degrees C). Maxwell-Wagner type of dielectric dispersion, negative temperature coefficient of resistance (NTCR), thermally activated conduction, and non-Debye type of relaxation are the output of the analysis. The ZSIMPWIN fitted Nyquist's data reveals the grain and grain boundary effect in the conduction mechanism. The analysis of temperature-dependent resistance evaluates thermistor constant (& beta;), sensitivity factor, stability factor, and activation energy; which can be tailored for thermistor-related applications. The study of the polarization-electric field (P-E) loop opens up the possibility of the ferroelectric property in the studied material.

Automated summary

In this study, the synthesis and characterization of a double perovskite BaKFeMoO6 were reported. The crystal structure, grain distribution, elemental composition, and electrical properties of the material were extensively investigated. The results suggest potential applications in photovoltaics and thermistors, as well as the possibility of ferroelectricity in the studied material.