Thesis-1997-Smith.pdf (3.27 MB)
The magnetic structure and magnetization distribution of the intermetallic compound U14Au51
thesis
posted on 2013-12-02, 14:27 authored by Jacqui G. SmithThe antiferromagnetic structure of the intermetallic compound U14AU5l has
been determined from neutron polarimetric measurements and refined by
combining these data with integrated intensity measurements. The structure
was found to be non-collinear with the U moments confined to the a- b
plane. The moments of the U atoms in each of the two sets of sixfold sites
are arranged hexagonally with rotations of 600 beetween them and the two
sets are rotated with respect to each other by 500
• The third (twofold) set
of U atoms has no ordered moment. These conclusions are in disagreement
with a previous determination of the magnetic structure from powder data
which gave a collinear structure with moments parallel to the c-axis. Magnetization
measurements made on single crystals in the temperature range
300-2K can be understood in terms of a transition to a non-collinear easy
plane antiferromagnetic structure stable below 22K. Polarized neutron measurements
have been used to determine the contribution of each of the U
sites to the susceptibility between 22 and 2K. These show that of the two
sixfold U sites, that with the smaller ordered moment contributes more than
half of the total susceptibility. The twofold site, which is characterized by a
small U-U separation, makes the smallest contribution.
History
School
- Science
Department
- Physics
Publisher
© J.G. SmithPublication date
1997Notes
A Doctoral Thesis. Submitted in partial fulfilment of the requirements for the award of Doctor of Philosophy of Loughborough University.EThOS Persistent ID
uk.bl.ethos.241669Language
- en