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The Structure of Yttrialite and Its Identification Using Laboratory and Synchrotron‐Based Powder X‐Ray Diffraction
Author(s) -
Heward William J.,
SarrafiNour Reza,
Gao Yan
Publication year - 2009
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1551-2916.2008.02916.x
Subject(s) - powder diffractometer , monoclinic crystal system , powder diffraction , synchrotron , diffractometer , paracrystalline , materials science , rietveld refinement , crystallography , x ray crystallography , diffraction , national laboratory , crystal structure , advanced photon source , impurity , analytical chemistry (journal) , instrumentation (computer programming) , chemistry , beamline , optics , physics , beam (structure) , organic chemistry , engineering physics , chromatography , computer science , operating system
A highly crystalline sample of the impurity stabilized phase y ‐Y 2 Si 2 O 7 , generally known as yttrialite, has been formed from the melt of a glass with a nominal composition of 62(SiO 2 )–10(Al 2 O 3 )–28(Y 2 O 3 ) mol%. Powder X‐ray diffraction patterns were collected using in‐house instrumentation and the 11‐BM diffractometer at the Advanced Photon Source, Argonne National Laboratory, Argonne, IL. Rietveld refinements were carried out on the patterns using two structural models. On patterns collected using in‐house instrumentation the correct structure assignment was difficult to determine; however, the extremely high‐quality data afforded by the 11‐BM instrument showed conclusively that the sample was found to crystallize in the monoclinic system (SG= P 2 1 / m ) with lattice parameters a =5.03032(6), b =8.06892(6), c =7.33620(6) Å, and β=108.673(1). Furthermore, simulations have shown that it is likely that this structure model can be used to describe natural yttrialite or yttrialite that is formed at low temperatures, though the possibility that such materials are paracrystalline is also discussed.