Electronic structure and magnetic properties of Si doped AlFe₂Ge full-Heusler

Abstract

Using the spin-polarized GGA combined with TB-mBJ approach and Monte Carlo program, we methodically explore the electronic and magnetic features of cubic Al1-xSixFe2Ge (x = 0, 0.25, 0.50, 0.75, and 1) compounds. The structural optimization in ferromagnetic and ferrimagnetic state proves that alloy AlFe2Ge is ferrimagnetic with optimized lattice constant of 3.6075Å. The elastic constants and related mechanical quantities such as bulk modulus B, Zener anisotropy factor A and Cauchy pressure Cp were calculated. The calculated total magnetic moment shows a slightly decreasing in their values on increasing Si substitution x. The results show that the studied compound has remarkable properties such as their high magnetic entropy at low temperature 40 J.Kg-1.K-1, metallicity and ferrimagnetism. Noting that ferrimagnetic compound is more suitable for spintronic devices than its ferromagnetic compound because of its lower leakage fields and favorable robustness of magnetism.