Cubic magnetic anisotropy of the antiferromagnetically ordered Cu3TeO6

A combination of highly sensitive torque magnetometry in low magnetic fields and a phenomenological approach to magnetic anisotropy is used to probe the symmetry of the antiferromagnetically ordered state of spin S = 1 / 2 system Cu3TeO6. The results show that the ordered state has four antiferromagnetic domains with spin axis in the 〈 1 ± 1 ± 1 〉 directions, in agreement with the previously reported neutron measurements. These results show that this approach, previously applied to ferromagnets and highly anisotropic antiferromagnets, is also successful in determining the symmetry of weakly anisotropic Heisenberg antiferromagnets with multiple spin domains. Possible microscopic origin of magnetic anisotropy is briefly discussed.