Field-induced transition of the magnetic ground state from A-type antiferromagnetic to ferromagnetic order in CsCo2Se2

F. von Rohr; A. Krzton-Maziopa; V. Pomjakushin; H. Grundmann; Z. Guguchia; W. Schnick; A. Schilling

doi:10.1088/0953-8984/28/27/276001

paper

Field-induced transition of the magnetic ground state from A-type antiferromagnetic to ferromagnetic order in CsCo2Se2

arXiv:1605.01113 · doi:10.1088/0953-8984/28/27/276001

Abstract

We report on the magnetic properties of CsCo $_{2}$ Se $_{2}$ with ThCr $_{2}$ Si $_{2}$ structure, which we have characterized through a series of magnetization and neutron diffraction measurements. We find that CsCo $_{2}$ Se2 $_{2}$ undergoes a phase transition to an antiferromagnetically ordered state with a Néel temperature of $T_{N} \approx$ 66 K. The nearest neighbour interactions are ferromagnetic as observed by the positive Curie-Weiss temperature of $Θ \approx$ 51.0 K. We find that the magnetic structure of CsCo $_{2}$ Se $_{2}$ consists of ferromagnetic sheets, which are stacked antiferromagnetically along the tetragonal \textit{c}-axis, generally referred to as A-type antiferromagnetic order. The observed magnitude of the ordered magnetic moment at $T$ = 1.5 K is found to be only 0.20(1) $μ_{Bohr}$ /Co. Already in comparably small magnetic fields of $μ_{0} H_{M M}$ (5K) $\approx$ 0.3 T, we observe a metamagnetic transition that can be attributed to spin-rearrangements of CsCo $_{2}$ Se $_{2}$ , with the moments fully ferromagnetically saturated in a magnetic field of $μ_{0} H_{FM}$ (5K) $\approx$ 6.4 T. We discuss the entire experimentally deduced magnetic phase diagram for CsCo $_{2}$ Se $_{2}$ with respect to its unconventionally weak magnetic coupling. Our study characterizes CsCo $_{2}$ Se $_{2}$ , which is chemically and electronically posed closely to the $A_{x} F e_{2 - y} S e_{2}$ superconductors, as a host of versatile magnetic interactions.