Lawrence Berkeley National Laboratory
Recent Work
Title
THEORY OF ANGLE-RESOLVED PHOTOEMISSION EXTENDED FINE STRUCTURE
Permalink
https://escholarship.org/uc/item/4s81w03k
Authors
Barton, J.J.
Robey, S.W.
Shirley, D.A.
Publication Date
1985-12-01
eScholarship.org Powered by the California Digital Library
University of California
LBL-19324
Preprint
~.
~
Lawrence
Berkeley
Laboratory
UNIVERSITY
OF
CALIFORNIA
Materials &
Molecular
Research Division
Submitted
to
Physical
Review
B
THEORY
OF
ANGLE-RESOLVED PHOTOEMISSION
EXTENDED
FINE
STRUCTURE
Ftb
2 6
1~86
liBRARY
AND
r--~~
..•
. -
.::.:NTS
SECT/ON
J.J.
Barton,
S.W.
Robey,
and
D.A.
Shirley
-
~
--
-~·
------~---
December
1985
(--
-
,_,
. TWO-WEEK
LOAN
COPY,
__
,
,.,:_
This
is
a Library
Circulating
Copy
~----------i
, -which may ,be,b()rrowed
for
two
·
..
·
·-~~--b·,_
~~
Prepared
for
the U.S. Department
of
Energy under Contract DE-AC03-76SF00098
DISCLAIMER
This document was prepared
as
an account of work sponsored
by
the United States
Government. While this document is believed to contain correct information, neither the
United States Government nor any agency thereof, nor the Regents
of
the University of
California, nor any
of
their employees, makes any warranty, express or implied, or
assumes any legal responsibility for the accuracy, completeness, or usefulness
of
any
information, apparatus, product, or process disclosed, or represents that its use would not
infringe privately owned rights. Reference herein to any specific commercial product,
process, or service by its trade name, trademark, manufacturer, or otherwise, does not
necessarily constitute or imply its endorsement, recommendation,
or
favoring by the
United States Government or any agency thereof, or the Regents
of
the University of
California. The views and opinions
of
authors expressed herein do not necessarily state or
reflect those
of
the United States Government or any agency thereof or the Regents
of
the
University
of
California.
1 .
LBL-19324
Theory
of
Angle-Resolved
Photoemission
Extended
Fine
Structure
ABSTRACT
J.J.
Barton,
S.W. Robey, and D.A.
Shirley
Materials
and
Molecular
Research
Division
Lawrence
Berkeley
Laboratory
and
Departments
of
Chemistry
and
Physics
University
of
California
Berkeley,
California
94720
We
present
a
theory
for
photoelectron
scattering
in
the
100-1000 ev
energy
range
designed
to
simulate
experimental
measurements
of
Angle-
Resolved
Photoemission
Extended
Fine
Structure
(ARPEFS)
from
ordered
surfaces.
The
zero-order
problem
of
photoabsorption
in
the
solid
is
treated
first,
followed
by a
scattering
problem
which
incorporates
the
scattering
ion-cores
in
a
perturbation
series
(cluster
expansion).
The
dynamics
of
core-hole
relaxation
are
discussed,
but
the
dynamical
effects
are
shown
to
be
small.
The
Taylor-series
magnetic
quantum
number
expansion
is
used
for
the
curved-wave,
multiple-scattering
equations.
We
argue
that
a
velocity-dependent
surface
barrier
gives
primarily
an
inner
potential
shift,
with
no
clear
evidence
for
surface
electron
refraction.
Analytic
formulas
for
aperture
integration
are
derived
and
thermal
averaging
in
a
correlated
Debye model
is
extended
to
multiple
scattering.
Reasonable
values
for
non-structural
parameters
in
the
theory
are
shown
to
give
very
good
simulations
of
the
experimental
ARPEFS
measurements from
c(2X2)S/Ni(001)
in
contrast
to
previous
theoretical
calculations.
We
find,
in
agreement
with
full
multiple-
scattering
calculations,
that
forward
focussing
is
a
fundamental
feature
of
ARPEFS
and
that
curved-wave
corrections
are
essential
for_
2
quantitative
results.
Since
the
scattering
path-length
difference
is
not
appreciably
altered
by
forward
scattering,
the
ARPEFS
oscillation
frequency
is
equal
to
the
geometrical
path
length
difference
plus
a
small
potential
phase
shift,
but
the
amplitude
and
constant
phase
of
the
oscillations
cannot
be
predicted
by
theories
based
upon
single-
scattering
or
plane-wave
approximations.
