Synergistic effects of Al and Co co-doping on structural, electrical and luminescence properties of gallium ferrites synthesized by sol-gel method

In the present manuscript, synergic impacts of aluminum and cobalt co-doping on the structural, optical, P-E and leakage current densities of gallium ferrite (GFO) have been investigated. We have synthesized polycrystalline Ga_1-xAl_xFeO₃ (x = 0.0, 0.50) and Ga_0.5Al_0.5Fe_1-yCo_yO₃ (y = 0, 0.025, 0.05) samples using the sol-gel method. XRD analysis shows the orthorhombic crystal structure corresponding to the Pc21n space group with no secondary or impurity peaks. The unit cell volume decreases with Al and Co co-doping in GFO. The leakage current density is significantly decreased (2.71 × 10⁻⁸ A/cm²) when Al and Co are co-doped in GFO. The ferroelectricity at room temperature is confirmed by the P-E measurements of the Al and Co co-doped GFO samples. The co-doped GFO samples showed better ferroelectric properties compared to bare sample. At room temperature, photoluminescence (PL) spectra have been recorded using 440 nm excitation for the reflection detections of Al and Co replacements on GFO. By using PL emission spectral analysis, the site disorder and cation redistribution have been also verified.