Linked Life Data

15018510

Source:http://linkedlifedata.com/resource/pubmed/id/15018510

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2004-3-15
pubmed:abstractText
The newly reported icosahedral quasicrystalline phase approximately Sc(3)Cu(2.1)Zn(12.9) was approached through four synthetic, structural, and EDX analyses of the range of approximants formed by systematic substitutions of 0-4 Zn by Cu in the reported Sc(3)Zn(17) as well as for the corrected Sc(3)Zn(18) (ScZn(6)) composition. Structures of high yield products of the 0, 1, 2, 3 Cu atom steps all refined as isotypic Sc(3)Cu(y)Zn(18-y) phases (Im(-)3, Z = 8, a = 13.8311(5) to 13.7528(5) A for 0 < or = y < or =2.2), basically isostructural with RCd(6) phases known for many rare-earth elements. The present phases all exhibit the novel feature of disordered zinc tetrahedra in the center of four concentric polyhedral clusters: pentagonal dodecahedron (Zn/Cu), icosahedron (Sc), icosidodecahedron (Zn), and triacontahedron (Zn). The Cu tuning process reduces both the average electron count per atom (e/a) to 2.04 and the average atom size until major amounts of the zinc-poorer quasicrystal separate along with the present normal crystalline phase near four added Cu. The Cu is an important neighbor to the disordered Zn atoms. The approximant structure repeatedly exhibits components with pseudo-icosahedral symmetry.
pubmed:language
eng
pubmed:journal
pubmed:status
PubMed-not-MEDLINE
pubmed:month
Mar
pubmed:issn
0020-1669
pubmed:author
pubmed:issnType
Print
pubmed:day
22
pubmed:volume
43
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1912-9
pubmed:year
2004
pubmed:articleTitle
Synthesis and structure of five Sc3CuyZn18-y-type compositions (0 < or = y < or = approximately 2.2), 1/1 crystalline approximants of a new icosahedral quasicrystal. Direct example of tuning on the basis of size effects and Hume-Rothery concepts.
pubmed:affiliation
Department of Chemistry, Iowa State University, Ames, IA 50011, USA.
pubmed:publicationType
Journal Article