First principles study of a new half-metallic ferrimagnets
Mn2–based full Heusler compounds:
Mn2ZrSi and Mn2ZrGe
Abstract
Half-metallic properties of new predicted Mn2-based full
Heusler alloys Mn2ZrSi and Mn2ZrGe have
been studied by first-principles full-potential linearized augmented
plane wave plus local orbital (FP-LAPW+lo) method based on density
functional theory (DFT). Our investigation is focused on the structural,
elastic, electronic and magnetic properties of these compounds. The
AlCu2Mn-type structure is found to be energetically more
favorable than the CuHg2Ti-type structure for both
compounds and are half-metallic ferrimagnets (HMFIs) with total magnetic
moments of 2.000 µB per formula unit, well
consistent with Slater-Pauling rule (Mtot = ( 24
– Ztot ) µB).
Calculations show that both the alloys have an indirect band gaps, in
the majority-spin channel, with values of 0.505 eV and 0.278 eV for
Mn2ZrSi and Mn2ZrGe, respectively. It
was found that Mn2ZrSi and Mn2ZrGe
preserved their half-metallicity for lattice constants range of
5.85–6.38 Å and 6.05–6.38 Å, respectively, and kept a 100% of spin
polarization at the Fermi level. Moreover, the calculated formation
energies and elastic constants confirm that these compounds are stable
chemically and mechanically, and the good crystallographic compatibility
with the lattice of semiconductors used industrially makes them
promising magnetic materials in spintronic applications.