Magnetic Susceptibilities of the Frustrated Triangular Lattice Antiferromagnets CsVCl3 and VX2 (X=Cl, Br and I):Appearance of Magnetic Liquid in the Ordered State

Magnetic susceptibilities χ of the frustrated triangular lattice antiferromagnets CsVCl 3 and VX 2 (X=Cl, Br and I) have been measured by means of the conventional Faraday-type as well as the SQUID magnetometers. The χ- T curve of CsVCl 3 shows a typical 1D-like character in agreement with the early work by Niel et al . At T < T N , χ c increases rapidly with decreasing T , whereas χ a stays at a constant value. The χ- T curve in VX 2 which are thought to be 2D-like systems is very flat and shows an anomaly at T N . Surprizingly, however, no anisotropy could be detected below T N . This suggests that the transition is quite different from the conventional one for the non-frustrated antiferromagnetic systems and a magnetic liquid state is formed in the ordered state.