High Field Magnetization of Solid Oxygen

High field magnetization of solid oxygen is measured in the pulsed field up to 500 kOe. The spin flop field H c in the antiferromagnetic α-phase is investigated in detail and exchange and anisotropy fields are evaluated. The obtained data are compared with previously determined parameters and magnetic properties of three solid phases are satisfactorily explained. The α-phase is two-dimensional antiferromagnet with intrinsic Néel temperature of 30 K and the β-phase consists of the triangular spin short range order while the one-dimensional short range order exists in the A-15 type γ-phase. The corresponding exchange constants in these phases are determined by using the theory of low-dimensional magnetism and a systematic change is obtained throughout three phases.