Structural, vibrational and magneto-electronic investigation of ruthenium based half heusler alloys: quantum-computational analysis

In this manuscript, the first theoretical study of half Heusler compounds RuCrZ (Z = Si, Ge) has been carried out in the context of Density Functional Theory (DFT). The structural, elastic-o-mechanical, electronic, vibrational and magnetic properties of half heusler alloy RuCrZ (Z = Si, Ge) were explored by WIEN2K Code. The energy of ground state and lattice constants were obtained using the optimization curves for both compounds. The elastic and mechanical properties confirmed that RuCrZ (Z = Si, Ge) were elastically stable as well as ductile. The energy band gap result shows there is no band gap for spin up channel that depicts the full metallic nature for RuCrGe while for spin down channel RuCrSi has largest band gap of 0.4 eV that corresponds to its polar nature as compared to the other alloys. The computed values of the lattice constant, as well as the other calculated physical characteristics, were quite close to the experimental values. In phonon dispersion curves optical branches are less coupled in RuCrGe while this effect is not at all observed in RuCrSi while magnetic moments of these materials are comparable to about 1μB, i.e., M_Tot ≈ 1 μB. (author)