Study of the effect of Sr²⁺ ions substitution on the dielectric behaviour of BaCr₂O₄ chromites synthesized by solution combustion method

In this paper, we report the structural, vibrational and electrical behavior of Sr²⁺ ions substituted barium chromite having the composition BaSr_xCr_2-xO₄ (x = 0, 0.1, and 0.2 mol %). The samples were synthesized by solution combustion method. The X-ray diffraction (XRD) analysis confirmed the formation of orthorhombic structure with space group Pnma for all the synthesized samples. The Fourier Transform Infrared (FTIR) spectra showed the two absorption bands in the wavenumber range of 556–638 cm⁻¹ corresponding to the Ba–O and Cr–O vibrations. The dielectric parameters and ac conductivity of the samples were studied as a function of frequency (100 Hz–100 kHz) at different temperatures. All the samples showed dielectric dispersion with frequency which is explained by Maxwell–Wagner type interfacial polarization. The frequency dependent ac conductivity analysis indicated that the conduction is due to the transfer of charge carriers between Cr²⁺ and Cr³⁺ ions. Complex Impedance Spectroscopy (CIS) has been used to study the nature of electrical relaxation behaviour present in the samples. The value of dielectric loss for BaSr_xCr_2-xO₄ (x = 0, 0.1, and 0.2 mol %) chromites is minimum, So, it can be utilized as a promising material for fabrication of high frequency device applications, and other electronic devices.