Decoupling of itinerant and localized $d$-orbital electrons in the compound Sc$_{0.5}$Zr$_{0.5}$Co

Abstract

By using the arc-melting method, we successfully synthesized the compound Sc$_{0.5}$Zr$_{0.5}$Co with the space group of $Pm$-$3m$. Both the resistivity and magnetic susceptibility measurements reveal a phase transition at about 86 K. This transition might be attributed to the establishment of an antiferromagnetic order. The magnetization hysteresis loop measurements in wide temperature region show a weak ferromagnetic feature, which suggests a possible canted arrangement of the magnetic moments. Bounded by the phase transition temperature, the resistivity at ambient pressure shows a change from Fermi liquid behavior to a super-linear behavior as temperature increases. By applying pressures up to 32.1 GPa, the transition temperature does not show a clear change and no superconductivity is observed above 2 K. The density functional theory (DFT) calculations confirm the existence of the antiferromagnetic order and reveal a gap between the spin-up and spin-down $d$-orbital electrons. This kind of behavior may suggest that the antiferromagnetic order in this compound originates from the localized $d$-electrons which do not contribute to the conductance. Thus the itinerant and localized $d$-orbital electrons in the compound are decoupled.