Search

Sc 2 -based all-d-metal Heusler alloys Sc 2 NiCu, Sc 2 NiCo and Sc 2 CoCu were synthesized successfully. XRD measurement suggests that they are single phase and crystallize in the L2 1 structure or L2 1 with a degree of atomic disorder, agreeing with the theoretical results that L2 1 structure has much lower total energy than XA. The phonon dispersion curves of L2 1 alloys have no imaginary frequency in the whole Brillouin zone, but for XA type alloys, obvious imaginary frequency can be observed, making them less stable. First-principles calculations indicate non-magnetic ground state for these alloys. Accordingly, the magnetizations of them at 5 K are very small and no magnetic ordering transition can be observed in their thermomagnetic curves. Sc 2 NiCu and Sc 2 CoCu show a metallic character in the ρ-T curves, while Sc 2 NiCo is semiconductor-like. The elastic constants are calculated and the results show that the three alloys are mechanically stable. The Pugh's ratio and Poisson's ratio are determined and indicate the ductile nature of them. Three new all-d-metal Heusler alloys were prepared by melt-spinning technique. Both powder X-ray diffraction patterns and first-principles calculations suggest that these alloys tend to crystallize in the L2 1 structure. Depending on the composition, these alloys show metal-like or semiconductor-like transport properties. [Display omitted] • New Sc 2 -based all-d-metal Heusler alloys Sc 2 NiCu, Sc 2 NiCo and Sc 2 CoCu were synthesized successfully. • Sc 2 NiCu and Sc 2 CoCu show metallic behavior while Sc 2 NiCo is semiconductor-like in their temperature-resistivity curves. • XRD, structural optimization and phonon spectrum suggest that these alloys prefer to form L2 1 structure. • Electronic structure and mechanical properties of Sc 2 NiCu, Sc 2 NiCo and Sc 2 CoCu were studied. [ABSTRACT FROM AUTHOR]