Fabrication and physical characteristics of K/W double doped BiFeO3 complex electro-ceramic; (Bi1/2K1/2)(Fe1/2W1/2)O3

Abstract

The main objective of this research work is to investigate the effect of the inclusion of potassium/tungsten (K/W) (at the Bi/Fe site) on the structural, dielectric, electrical, and optical characteristics of eco-friendly BiFeO3 to assess its potential use for multifunctional applications including energy storage. The standard solid-state reaction method was used to synthesize the desired (Bi1/2K1/2)(Fe1/2W1/2)O3 complex compound. Examination of X-ray diffraction data demonstrates the structural transformation of bismuth ferrite from rhombohedral to monoclinic on the addition of K/W. The estimated crystallite size is 52 nm. The standard cell parameters include a = 12.1967 Å, b = 9.0468 Å, c = 6.4971 Å, and β = 105.02°, resulting in a cell volume of 692.40 Å3. Analysis of Raman spectra reveals a slight alteration in intensity and displacement of Raman mode positions, attributed to the doping effect, which confirms the incorporation of K and W ions into the BiFeO3 lattice. Scanning electron microscopy provides an image indicating the dense surface structure of the sample. Elemental analysis through energy-dispersive X-ray spectroscopy verifies the presence and purity of the constituent elements. The material doped with potassium and tungsten exhibits a high dielectric constant (εr ∼ 3 × 103) and low tangent loss (tanδ ∼1). The extensive dielectric studies conducted across various frequencies and temperatures suggest that the sample possesses capacitive properties. The depression angle of 8.51° reflects the extent of deviation from Debye's behavior. The presence of hysteresis loops indicates the presence of ferroelectric behavior.