Mapping the magnetization density near magnetic atoms in copper: Nuclear magnetic resonance studies of CuMn and CuCr
Aton, Thomas John
This item is only available for download by members of the University of Illinois community. Students, faculty, and staff at the U of I may log in with your NetID and password to view the item. If you are trying to access an Illinois-restricted dissertation or thesis, you can request a copy through your library's Inter-Library Loan office or purchase a copy directly from ProQuest.
Permalink
https://hdl.handle.net/2142/25651
Description
Title
Mapping the magnetization density near magnetic atoms in copper: Nuclear magnetic resonance studies of CuMn and CuCr
Author(s)
Aton, Thomas John
Issue Date
1976
Doctoral Committee Chair(s)
Slichter, C.P.
Department of Study
Physics
Discipline
Physics
Degree Name
Ph.D.
Degree Level
Dissertation
Keyword(s)
magnetization density
copper
nuclear magnetic resonance
Copper Manganese (CuMn)
Copper Chromium (CuCr)
Language
en
Abstract
"Using nuclear magnetic resonance, we have measured the magnetization
density at the nuclear sites of several copper near neighbor shells surrounding
the impurities manganese and chromium in the dilute alloys CuMn
and CuCr. The resonances of these neighbor shells appear as weak ""satellite""
resonances near the iutense resonance produced by the majority of
the copper nuclei which are far from any impurity. We have observed
satellites for eight distinct shells in CuMn and six distinct shells in
CuCr. These data are the first reported on satellites in CuCr and on all
but three of the CuMn satellites. The magnetization density at each
shell is directly proportional to the frequency shift of the resonances
of that shell relative to the resonance of pure copper metal when observing
at fixed magnetic field.
Experiments are described on both powdered and single crystal alloy
samples. The satellite signals are much stronger in powdered samples,
but single crystals give more information. Powdered samples are used to
find the satellites and measure the temperature dependence of their frequency
shifts. To identify the shells producing the satellites, single
crystals are necessary. Placing the applied field along three different
crystal axes, we use the different symmetries of the shells with respect
to the impurity atoms to make these identifications.
From the CuMn data, we identify the satellites of the first four
neighbor shells. For CuCr, we identify the satellites of shells one,
three, and four and place a small upper limit on the shift of the second
neighbor shell. In both alloys, the tensors describing the magnetic
hyperfine and electric field gradient anisotropics are worked out for
several shells. The map of the magnetization density made possible by
the satellite identifications provides much more detailed information
about the structure of these magnetic impurities than previously available.
At high temperatures, we find the temperature dependence of the
satellite shifts in CuCr differs from that expected from previous low
temperature measurements of the magnetic susceptibility."
Use this login method if you
don't
have an
@illinois.edu
email address.
(Oops, I do have one)
IDEALS migrated to a new platform on June 23, 2022. If you created
your account prior to this date, you will have to reset your password
using the forgot-password link below.
