Anisotropy in transport and magnetic properties of K0.64Fe1.44Se2

We report a study of anisotropy in transport and magnetic properties of K0.64Fe1.44Se2.00 single crystals. The anisotropy in resistivity is up to one order of magnitude between 1.8 K and 300 K. Magnetic susceptibility exhibits weak temperature dependence in the normal state with decrease in temperature with no significant anomalies. The lower critical fields Hc1 of K0.64Fe1.44Se2.00 are only about 3 Oe and the anisotropy of Hc1,c/Hc1,ab is about 1. The critical currents for H||ab and H||c are about 10-10^3 A/cm2, smaller than in iron pnictides and in FeTe_{1-x}Se_{x} and nearly isotropic.