#
# arev:/usr/local/unicat/unireq/beamreq/req00081.txt
# UNICAT Member Beam Time Request  #81

# created Wed Sep 29 14:13:45 CDT 1999
#

collaboration:
	Yes

days:
	5

description:
	Several months ago, we completed the first APS experiment to study
	magnetism in K2ReBr6 using resonant x-ray techniques.  We found clear
	evidence of magnetic scattering associated with the Re LIII and LII 
	edges.  We quickly searched for scattering at the LI edge and Br K 
	edge and found no clear evidence of such scattering.  However, the 
	experiment was somewhat limited by the geometry used and the shape
	of the radiation shroud.  The experiment should be able to be greatly
	enhanced by the use of an extended face geometry with a cleaved and
	polished surface.  In the meantime, we have performed powder neutron
	measurements which have allowed us to understand the low temperature
	structure which differs substantially from the room temperature structure
	(there are a series of phase transitions which transform the system 
	from cubic to monoclinic).  This should allow us to better understand
	the low temperature domain structure which has been clearly seen with
	both neutrons and x-rays.  With these improvements, we expect to 
	improve on the results obtained previously and to possibly be able to
	observe magnetic resonant scattering associated with the Br K edge.
	

equipment+required:
	displex

experiment:
	Magnetic X-ray scattering study of K2ReBr6

hazards:
	

name:
	Mark D. Lumsden

nonmembers:
	Mark D. Lumsden / Stephen E. Nagler

station:
	33ID-D

unacceptable+dates:
	None



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