We present studies of the structural optimization of the full Heusler alloys Co2XZ (X = Ti, Hf, and Z = Si, Ge, Al) and their electronic, magnetic, mechanical, and thermoelectric properties using first-principle calculations. The structure of these alloys was found to be stable in the cubic phase with Fm \(\overline{3 }\) m space group in their ferromagnetic phase. The total magnetic moment of these alloys satisfies the Slater–Pauling rule and predicts their ferromagnetic half-metallic character. The elastic constants suggest that they are mechanically stable and ductile. The electronic density of states and band structure calculations reveal that these alloys exhibit half-metallic behavior with high spin polarization in their stable ferromagnetic phase. Investigation of thermoelectric properties reveals that Co2HfAl exhibits a relatively high Seebeck coefficient (S) and figure of merit (ZT) (S = −110 µV/K and ZT = 0.4 at 800 K) as compared to the other studied alloys. The results for these alloys predict their potential application as spintronic and thermoelectric materials.
