A new oxygen-free cobalt-based compound SmCoAsF with multiple magnetic transitions

Abstract

A new quaternary oxygen-free cobalt-based compound, SmCoAsF, which crystallizes with a tetragonal ZrCuSiAs-type structure, was synthesized via a solid state metathesis (SSM) reaction. The lattice constants a and c of SmCoAsF were 3.9555(0) Å and 8.2462(2) Å, respectively. Based on the measurements of electrical resistivity and magnetization, it was inferred that the as-synthesized sample mainly underwent a ferromagnetic (FM) transition at T_c ∼ 70 K, followed by an antiferromagnetic (AFM) transition at a lower temperature, T_N1 ∼ 40 K. The third magnetic transition at T_N2 ∼ 6 K was also observed clearly in the magnetic measurements. SmCoAsF with a rich magnetic phase is expected to be a new member of the quaternary cobalt-based system and contribute to the explorations of the origin of magnetic state transitions.