Antiferromagnetic critical phenomena in USb

We present further experimental and theoretical insights into unusual 'two-component' antiferromagnetic critical phenomena in uranium antimonide. High resolution neutron powder diffraction measurements have been used to quantitatively describe the growth of the staggered magnetisation below T-N similar to 212 K. Further insight into the critical properties of USb has been provided by vibrating sample magnetometry. The observed susceptibility is found to increase on warming towards TN in a manner compatible with 3D Heisenberg behaviour. The data are discussed in the context of previous observations of two-component X-ray critical scattering (Phys. Rev. B 54 (1996) 15234). Scaling and related considerations are applied to the critical exponents determined by the different techniques. The scaling properties provide insights into the possible origin of unusual 'two-component' critical phenomena in this material. (C) 2002 Elsevier Science B.V. All rights reserved.