####################################################
# Martin Holt <mvholt@uiuc.edu>
# requesting 3 days, at minimum=2 days
# beamline 33ID, "Investigation of low temperature phase transitions in SrTiO3"
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# top:/home/www/beamtime-requests/req00250.txt
# UNICAT Member Beam Time Request  #250
# created Fri Mar 15 19:55:12 CST 2002
####################################################

beamline:
	33ID

collaboration:
	Yes

contact:
	mvholt@uiuc.edu

days:
	3

description:
	Strontium titanate undergoes two low temperature phase transitions 
	(37K and 63K) distinct from the more well understood second order
	displacive transition at ~110K.  The mechanism of these transitions
	has been assigned to both R-point phonon hardening / phonon mode
	coupling and (seperately) indication of a novel quantum paraelectric
	regime.  The proposed experiment is to collect diffuse and
	crystallographic data as a function of temperature below 100K at the 
	R-point in reciprocal space.  Suitable analysis of the lineshapes may
	indicate the nature of long-range order onset and the role R-point phonons
	play in this transition.

equipment+required:
	He displex, high resolution diffractometer

experiment:
	Investigation of low temperature phase transitions in SrTiO3

foreign+nationals:
	

hazards:
	closed cycle He displex

minimumdays:
	2

name:
	Martin Holt

new+request:
	on

nonmembers:
	

unacceptable+dates:
	August 4-10  May 4-6


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