Magnetism in neodymium at high pressure

Abstract

We have carried out magnetic neutron diffraction studies of a single crystal of neodymium at high pressure, using clamp cells on the diffractometer D10 at the Institut Laue-Langevin, Grenoble. The magnetic ordering was investigated at pressures up to 14 kbar in the temperature range 1.4-25 K. A number of quite different magnetic phases were observed, including the coexistence of ferromagnetic and antiferromagnetic ordering of moments on the inequivalent crystallographic sites. The structures formed and the population of the different symmetrically equivalent domains appear to be affected by complex interactions between the cubic-site ferromagnetism, the antiferromagnetic hexagonal-site ordering and a uniaxial component of stress.

Evidence for strong enhancement of the magnetic ordering temperature of trivalent Nd metal under extreme pressure

“…That the knee for Dy at T o does indeed arise from magnetic ordering is supported by recent Synchrotron Mössbauer Spectroscopy (SMS) studies to 141 GPa 18 . Referring to Fig 2(a), the temperature of the R(T )-knee for Nd agrees with the magnetic ordering temperature from magnetic studies on Nd to 1.4 GPa pressure 19 . However, for higher pressures, particularly above ∼40 GPa, the identification of the R(T )-knee with magnetic ordering is less clear due to the greater spatial extent of Nd's 4f wave function compared to that of Dy.…”

Epitaxial Ce and the magnetism of single-crystal Ce/Nd superlattices

“…The behavior of samples with 20-or 30-plane thick Nd layers can be compared to the behavior of Nd under applied pressure. Experiments by Watson et al 30 show a sequence of changes to the magnetic structure with increasing pressure. For an applied pressure of 8.2 kbar the 4-q magnetic structure is suppressed and c-axis ferromagnetic ordering on the cubic sites is induced.…”