Single crystal growth and physical properties of BiS2-layered compound Eu3Bi2S4F4

We have for the first time succeeded in growing single crystals of Eu3Bi2S4F4 by CsCl-flux method and performed magnetic property measurements. Magnetization measurements ascertained that the antiferromagnetic transition appears at T-N = 2.2 K. The effective moment estimated from a Curie-Weiss (CW) fitting above 150 K is smaller than the free ion value for Eu2+, indicating that the average valence of Eu ions deviates from divalent. Weak magnetic anisotropy develops below 20 K. From CW fitting at low temperatures, we found the difference in Curie Weiss temperature between H parallel to[001] and H perpendicular to[100], indicating the anisotropy of magnetic interaction between Eu ions. In the magnetization curve at 2 K (below T-N), a metamagnetic anomaly appears only for the [001] direction around 0.7 T. Since this anomaly disappears above T-N, this transition originates from the spin flip of Eu magnetic moments by applying magnetic field. This finding indicates that the ordered moments in the antiferromagnetic state are parallel to the [001] direction, being consistent with the anisotropic Weiss temperature, which is 20% larger for this direction.