Observation of a Quadruple-qMagnetic Structure in Neodymium

Major progress has been made in understanding the complicated magnetic structures exhibited by dhcp neodymium metal. New evidence for the 2-q model of the structure between 19.1 and 9 K has been discovered in neutron-diffraction studies of intermodulation harmonics of the type 2qᵢ±qⱼ. We have applied the same technique at 4.5 K and below. From an analysis of the harmonic combinations observed, we propose a new model for the lowest-temperature phase of Nd; it is characterized by a multidomain 4-q structure in which the magnitude and direction of each component wave vector is different.