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# Aaron Gray <ajgray@uiuc.edu>
# requesting 4 days, at minimum=3 days
# beamline 33ID, Pb films on Si substrates near the melting temperature
# instrument 33ID-E surface
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# top:/home/www/beamtime-requests/req01035.txt
# UNICAT Member Beam Time Request  #1035
# created Thu Aug 24 21:01:07 CDT 2006
####################################################

apsrun:
	2006-03

beamline:
	33ID

collaboration:
	Yes

contact:
	ajgray@uiuc.edu

days:
	4

description:
	Solid thin films have been studied widely and continue to be of interest, however their liquid counterparts have not received as much attention.  It has proven somewhat difficult to study Pb films grown on Si substrates near the melting transition, due to the fact that they dewett as the melting temperature is approached.  This dewetting behavior is dependent on the thickness of the film, and it is likely that the films will remain flat if they are sufficiently thick.  In this experiment Pb films, over 75 monolayers thick, will be grown on Si substrates.  These films will be heated above the Pb melting temperature, while the x-ray reflectivity is being observed.  This will provide a better understanding of the thickness dependence of the dewetting behavior, in this system.   Scattering at small angles from the liquid may also be observable for sufficiently thick films.  Furthermore the nature of the solid liquid transition can be studied, although in the bulk case the transition is first order it may be continuous for a film.  Previous studies, examining the reflectivity at small angles, from bulk liquid metals show surface induced layering, capillary wave effects.  This study may be able to shed light on the effect of decreasing the thickness of the liquid, and what role quantum size effects may play in the liquid structure as well as the solid liquid transition.

equipment_required:
	

experiment:
	Pb films on Si substrates near the melting temperature

foreign_nationals:
	

hazards:
	

instrument:
	33ID-E surface

instrument_other:
	

minimumdays:
	3

name:
	Aaron Gray

nonmembers:
	

submit:
	Submit

unacceptable_dates:
	

z34ID_change_undulator:
	no

z34ID_details:
	

z34ID_parasitic:
	no


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