Abstract
First-principles calculations accomplished to investigate structural, mechanical, thermal and magnetic properties of newly designed CoNbCrZ (Z = Al, Ga, Si, Ge) Heusler alloys (HAs). Generalized gradient approximation (GGA) and Hubbard potential (GGA + U) are used as exchange correlation functional. Geometry optimization calculations show that all these HAs are stable in Type I structure. Further calculations are carried out for non-magnetic (NM) and magnetic phases and found that all considered alloys are stable in ferromagnetic (FM) phase. GGA and GGA + U approximations executed to obtain electronic structures of CoNbCrZ (Z = Al, Ga) HAs, while GGA approximations performed for CoNbCrZ (Z = Si, Ge) HAs. Magnetic properties revealed that following alloys i.e. CoNbCrAl and CoNbCrGa are complete half-metals (HM) while CoNbCrSi and CoNbCrGe are NM semi-metals in nature. All these alloys are obeying Slater-Pauling rule (M-t = 24-Z(t)) and calculated magnetic moments are in well agreement. Mechanical parameters show that all alloys are stable and ductile in nature as well as have anisotropic behavior. High Debye temperature and melting temperature also authenticate the thermal stability of these alloys. Furthermore, negative formation (E-f) energy indicated that all these alloys could be synthesized experimentally.