Magnetic Structures Refinements of High-Pressure Phases of Rare Earth Metals using Spallation Neutron Source

Neutron diffraction experiments are useful for determining both nuclear and magnetic structures of a material. Novel large volume diamond anvil cells (DAC) have been developed for use in neutron diffraction experiments to reach pressures exceeding 20 GPa. Rare earth elements dysprosium (Dy) and holmium (Ho) were studied using neutron diffraction to pressures of 22 GPa and 27 GPa respectively and cooled to 15 K. Previous experiments have determined the magnetic structure in the ambient pressure hexagonal close-packed (hcp) phase but have not resolved magnetic ordering in the high-pressure alpha-Samarium (α-Sm) and double hexagonal close-packed (dhcp) phases. We present experiments resolving magnetic ordering observed in the high pressure α-Sm and dhcp phases at low temperatures. The incommensurate and commensurate magnetic structure in rare-earth metals were determined from magnetic structure refinement of the data.