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# Peter Czoschke <czoschke@uiuc.edu>
# requesting 6 days, at minimum=2 days
# beamline 33ID, "Preferred height and bilayer relaxation of Pb islands on Si(111)(7x7)"
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# top:/home/www/beamtime-requests/req00248.txt
# UNICAT Member Beam Time Request  #248
# created Fri Mar 15 14:21:33 CST 2002
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beamline:
	33ID

collaboration:
	Yes

collaborator+Hawoong:
	on

contact:
	czoschke@uiuc.edu

days:
	6

description:
	Low temperature growth of thin Pb films on clean Si(111) creates 
	self-organized 2 dimensional Pb islands whose physical properties
	could be strongly influenced by quantum size effects (QSE).  If
	this is the case, it would result in both a non-uniform distribution
	of island height ("preferred" or "magical" island heights), and an
	out-of-plane bilayer relaxation of atomic positions within the islands.
	
	To examine this effect, we propose a low temperature deposition using
	the surface x-ray diffraction chamber in 33-IDE.  By controlling the
	coverage and annealing temperature of the deposition, the "magical"
	height of the Pb islands will be probed.  By collecting the
	reflectivity and other crystal truncation rods of the Pb/Si(111)
	system, we can extract the nanoscale properties by fitting with a
	simple model that predicts both population and layer relaxations
	within the islands.
	
	Please break the run up into 2 separate time periods of 2-3 days each,
	separated by a few days.  Thanks.

equipment+required:
	33-IDE surface diffraction chamber

experiment:
	Preferred height and bilayer relaxation of Pb islands on Si(111)(7x7)

foreign+nationals:
	Dr. Z. Q. Ma

hazards:
	Liquid N2 will be used to cool the sample.

minimumdays:
	2

name:
	Peter Czoschke

nonmembers:
	

unacceptable+dates:
	May 29-June 3
	June 7-10
	June 20-24
	June 27-July 1
	July 12-15


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