This study explores the effects of aluminum doping on the structural, magnetic, and superconducting properties of magnesium diboride (MgB2). Aluminum was introduced to synthesis \({\text{M}\text{g}}_{1-\text{x}}{\text{A}\text{l}}_{\text{x}}{\text{B}}_{2}\) samples at doping levels of x = 0.03, 0.06, and 0.12. Structural characterizations revealed slight changes in bond lengths and bond angles, indicating successful Al substitution without significant lattice distortion. Doping (x = 0.12) increases the critical current density, indicating better vortex pinning by raising temperature, according to magnetization tests.
In contrast, a higher doping level (x = 0.12) reduces both the superconducting transition temperature and critical current density. Specifically, the transition temperature decreased from approximately 38.5 K at lower doping levels to about 35 K at the highest doping. For this highly doped sample, critical current densities were found to be \(0.93\times{10}^{9}A/{cm}^{2}\) , \(1.57\times{10}^{9}A/{cm}^{2}\) , and \(1.64\times{10}^{9}A/{cm}^{2}\) at 5 K, 15 K, and 20 K, respectively, reflecting the temperature-dependent pinning behavior at high doping. These findings reveal a sensitive balance in aluminum doping, where moderate amounts boost superconducting properties, but excessive doping reduces its performance. This work highlights the potential of controlled Al doping for optimizing MgB2 superconductors for technological applications.
