Critical scattering from erbium

Neutron scattering techniques have been used to measure the nature of the phase transition in erbium at TN=87 K from paramagnetism to an incommensurate longitudinally ordered phase with q=0.283 along c at TN. A high-purity crystal showed normal critical scattering in the paramagnetic state with a different correlation length in the basal plane and along c. It is found that γ=0.96±0.06 and both correlation lengths diverge with the same critical …