Effect of H on the crystalline and magnetic structures of the YCo3-H(D) system. I. YCo3 from
neutron powder diffraction and first-principles calculations

Cui, X-Y; Liu, J; Georgiev, PA; Morrison, I; Ross, DK; Roberts, M; Anderson, KA; Telling, M; Fort, D

Abstract

This paper reports investigations into the influence of hydrogen on the magnetic properties of the YCo3-H
system. We report results on the magnetic structure and magnetic transitions of YCo3 using a combination of
neutron powder diffraction measurements and first-principles full potential augmented plane wave + local
orbital calculations under the generalized gradient approximation. The ferromagnetic and ferrimagnetic structures
are examined on an equal footing. However, we identify that, no matter which structure is used as the
starting point, the neutron diffraction data always refines down to the ferrimagnetic structure with the Co2
atoms having antiparallel spins. In the ab initio calculations, the inclusion of spin-orbit coupling is found to be
important in the prediction of the correct magnetic ground state. Here, the results suggest that, for zero external
field and sufficiently low temperatures, the spin arrangement of YCo3 is ferrimagnetic rather than ferromagnetic
as previously believed. The fixed spin moment calculation technique has been employed to understand
the two successive field-induced magnetic transitions observed in previous magnetization measurements under
increasing ultrahigh magnetic fields. We find that the magnetic transitions start from the ferrimagnetic phase
�0.61�B/Co� and terminate with the ferromagnetic phase �1.16�B/Co�, while the spin on the Co2 atoms
progressively changes from antiparallel ferrimagnetic to paramagnetic and then to ferromagnetic. Our neutron
diffraction measurements, ab initio calculations, and the high field magnetization measurements are thus
entirely self-consistent.

Citation

neutron powder diffraction and first-principles calculations. Physical review B: Condensed matter and materials physics, 76(1), 184443-184454. https://doi.org/10.1103/PhysRevB.76.184443

• Journal Article Type: Article
• Publication Date: Jan 1, 2007
• Deposit Date: Nov 25, 2010
• Publicly Available Date: Apr 5, 2016
• Journal: Physical Review B (PRB)
• Print ISSN: 1098-0121
• Publisher: American Physical Society
• Peer Reviewed: Peer Reviewed
• Volume: 76
• Issue: 1
• Pages: 184443-184454
• DOI: https://doi.org/10.1103/PhysRevB.76.184443
• Publisher URL: http://dx.doi.org/10.1103/PhysRevB.76.184443
• Additional Information: Corporate Creators : UNIVERSITY OF SALFORD, RUTHERFORD APPLETON LABORATORY, UNIVERSITY OF BIRMINGHAM