Neutron Diffraction Studies of Some Rare Earth-Transition Metal Deuterides.
Abstract
Neutron diffraction experiments were performed on Ho6Mn23. At 77K it is found to have a face-centered cubic crystal structure and a non-collinear magnetic structure, with the Ho moments tilted at an angle of 33.4 to the Mn moments. The Ho atom carries a moment of 3.8 mu sub B, while the Mn moments at the b, d, f sub 1 and f sub 2 sites are 2.1, 2.0, 2.2 and 1.9 mu sub B respectively, comparable to those found in Y6Mn23. The very low moment on the Ho atom is rationalized as resulting from the fanning of the weakly coupled rare earth moments around the net Ho moment direction, giving a low spatially averaged value. Neutron diffraction studies of three Y6(Fe1-xAlx)23 compounds (x=0.05, 0.10, 0.15) at 523K and 77K reveal substantial preferential atomic ordering of Fe and Al atoms on the four transition crystallographic sites. The Fe atoms exhibit different magnetic moments on the four sites. The ternary alloys, Y6(FexMn1-x)23, exhibit interesting magnetic behavior over a range of solid solutions of iron and manganese. The effects of the substitution of Fe by Al in the R2 (Fe1-xAlx)14B compounds (R = Y, rare earths) on their magnetic properties have been investigated. The present experimental data indicate that intermetallic compounds based on Nd2(Fe1-x-yAlxCoy)14B have both high Curie temperatures and high coercive fields. The magnetocrystalline anisotropy of (Nd1-xSmx)2Fe14B and (Nd1-xPrx)2Fe14B has been studied by X-ray and magnetic measurements. Keywords: Rare earth-transition metal alloys and hydrides; Permanent magnets; Sublattices.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1986
- Accession Number
- ADA168995
Entities
People
- William J. James