MX$sub 2$ COMPOUNDS OF THORIUM AND THE POLYMORPHISM OF THORIUM DISILICIDE

Journal Article · Thu Aug 10 04:00:00 EDT 1961 · Acta Cryst.

DOI:https://doi.org/10.1107/S0365110X61002497· OSTI ID:4843683

Brown, A

The crystal structures of phases with the composition ThX/sub 2/ were examined using x-ray powder and single-crystal techniques. Where X is Ni, Cu, Ag, Au, Zn, Cd, Al, or Si ( beta -ThSi/sub 2/) crystal structures of the C32-type are found. Where X is Si ( alpha -ThSi/sub 2/) or Ga, the structures are of the C/sub c/ type. Related non-stoichiometric phases are ThSi/sub 1.6//sub 7/ (defect C32-type), ThGe/sub 1.5/ (distorted, defect C32-type), and ThGe/sub 1.6// sub 2/ (defect C/sub c/ type). Stoichiometric ThGe/sub 2/ is an Aface-centered orthorhombic structure. Consideration of these phases suggests that their crystal structures are influenced by the atomic radius r and the valency e of the X atom. Low values of e r are reflected-in crystal structures of the C32-type. Si has a critical value of e r and ThSi/sub 2/ is dimorphic. Ge has the highest value of e r and ThGe/sub 2/ has an orthorhombic structure which may be derived from the C32 or C/sub c/ structures. The non-stoichiometric phases are formed at the boundary between two structure types. (auth)

• Research Organization: General Electric Co. Ltd., Hirst Research Centre, Wembley, Eng.
• NSA Number: NSA-15-027606
• OSTI ID: 4843683
• Journal Information: Acta Cryst., Journal Name: Acta Cryst. Vol. Vol: 14
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ALLOTROPY
ALUMINUM
CADMIUM
CHEMISTRY
CONFIGURATION
COPPER
CRYSTALS
GALLIUM
GERMANIUM
GOLD
LATTICES
MONOCRYSTALS
NICKEL
PHASE DIAGRAMS
POWDERS
SILICIDES
SILICON
SILVER
THORIUM COMPOUNDS
X RADIATION
ZINC