A Computational exploration of the electronic, mechanical, and magnetic properties of Co2A1_ xBxAl full heusler alloys (A, B = Cr, Mn, and Fe)

An investigation of the structural, mechanical, electronic, magnetic, and thermomagnetic properties of Co2A1_xBxAl full Heusler alloys (where A, B = Cr, Mn, and Fe, and x ranges from 0 to 1.0) has been carried out using density functional theory (DFT) and Monte Carlo simulations. The investigation reveals small variations in lattice parameters and elastic modulus across the different compositions. The band gaps, calculated using modified Becke-Johnson (mBJ) potential, are found to be approximately 1.4 eV for Co2CrAl and Co2MnAl, while a lower band gap of 0.8 eV is observed for Co2FeAl, which also exhibits the highest total magnetic moment of 5 mu B. The doped structures display band gaps and magnetic moments that are intermediate to the pure compounds. The Fe-Co exchange interaction is identified as the most robust, significantly contributing to the high Curie temperatures in Fe-containing compounds, reaching up to 1120 K in the Co2FeAl alloy. Furthermore, the study underscores the strategic use of atomic substitution as an effective approach to manipulating key properties of these Heusler alloys. The ability to modulate band gaps, magnetic moments, and Curie temperatures through atomic substitution offers a promising pathway for optimizing these materials for specific technological applications, aligning with the needs of advanced functional devices.