Effect of substituting sp-element on half metallic ferromagnetism in NiCrSi Heusler alloy

The investigation of the electronic and magnetic properties of semi Heusler alloy, NiCrSi and alloys obtained by substituting Si with Ge and P (i.e. NiCrGe and NiCrP) has been presented. The present work aims to search the new candidates showing half metallic (HM) ferromagnetism using all-electron full potential linearized augmented plane wave (FPLAPW) method within generalized gradient approximation (GGA) formalism for exchange and correlation (XC) effects. We predict that these alloys are true half metallic ferromagnets (HMFs), showing an indirect band gap in minority density of states (DOS). This gap is largest in case of NiCrSi (0.91 eV). The substitution of sp-element in NiCrSi results in the minority band gap reduction. The main contribution in total magnetic moment comes from Cr-3d states. Moreover, it has an integer value in present alloys as expected in accordance with the Slater-Pauling (SP) rule.

► The minority band gap of NiCrGe has been predicted first time.
► Effect of substituting sp-element (Si to Ge/P) on minority band gap in NiCrSi has been analyzed.
► No other study using GGA in the literature yet exist for present alloys upto best of our knowledge.
► The total magnetic moments of present alloys scale accurately with Slater-Pauling rule.