Neutron diffraction study of the crystal and magnetic structures of antiferromagnetic manganese deuteride at high temperatures and high pressures
Phys. Rev. B 111, 224413 – Published 12 June, 2025
DOI: https://doi.org/10.1103/yf8k-cy61
Abstract
The crystal and magnetic structures of antiferromagnetic Mn deuterides formed by hydrogenating Mn metal at high temperature and high pressure, fcc γ- and hcp ε-, were investigated using in situ neutron powder diffraction. Deuterium atoms partially occupied the octahedral interstitial positions of the fcc and hcp metal lattices. The site occupancies increased rapidly with decreasing temperature from the deuteride formation temperatures of 875–900 K to approximately 450 K and remained at steady values down to 300 K. The Néel temperature of 543(10) K was determined for γ- from the appearance of a magnetic scattering peak during decreasing temperature. For ε-, the saturation magnetic moment and Néel temperature were determined to be 0.82(1) and 347(3) K, respectively, from the variations of magnetic moment with temperature. The Néel temperatures determined for γ- and ε- are consistent with those predicted by the respective Slater-Pauling curves proposed in previous studies based on the rigid-band model. These updated Néel temperatures provide insight into the development of more accurate Slater-Pauling curves based on electronic band structure calculations.
