Bonding in scandium monosulfide a NaCl crystal type

Technical Report · Fri Aug 01 04:00:00 EDT 1980

DOI:https://doi.org/10.2172/5134569· OSTI ID:5134569

Merrick, J. A.

The transition temperature of an order-disorder transition in Sc/sub 0/ /sub 81/S (R anti 3m to Fm3m) occurs at 700/sup 0/C. A group of ordered sublattices on the NaCl-type lattice (Fm3m) was generated and a Madelung energy and configurational entropy were calculated for each sublattice assuming the ions to be Sc/sup 2/ /sup 48 +/ and S/sup 2 -/. Mean field and pair interaction approximations were used to model long-range and short-range orderings, respectively. The electrostatic model fails to predict the observed short-range and long-range orderings. The high temperature vaporization of ScP was investigated by mass spectrometry and target collection Knudsen effusion at 1767 to 2209K. The composition ScP/sub 1/ /sub 00/ vaporizes congruently to the gaseous species Sc, P, and P/sub 2/. A temperature independent third law enthalpy of atomization (..delta..H/sup 0//sub atom,298/ = 252.2 +- 2.8 kcal mole/sup -1/) has a value approx. 12 kcal larger than that reported for ScS. Nonrelativistic, nonself-consistent LAPW band structure calculations are reported for ScS. XPS and UPS measurements are reported for Sc/sub 2/S/sub 3/ and several compositions Sc/sub 1-x/S (0.0 less than or equal to x less than or equal to 0.2). The Sc and S 2p binding energies (XPS) obtained for the defect scandium monosulfides are very close to those found in the pure elements, suggesting covalent bonding. The Sc 2p energy region has an interesting satellite structure.

• Research Organization: Ames Lab., IA (USA)
• DOE Contract Number: W-7405-ENG-82
• OSTI ID: 5134569
• Report Number(s): IS-T-896
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
BAND THEORY
BINDING ENERGY
CHALCOGENIDES
CRYSTAL-PHASE TRANSFORMATIONS
ELECTRONIC STRUCTURE
ENERGY
PHASE TRANSFORMATIONS
PHOSPHIDES
PHOSPHORUS COMPOUNDS
PHYSICAL PROPERTIES
PNICTIDES
SCANDIUM COMPOUNDS
SCANDIUM PHOSPHIDES
SCANDIUM SULFIDES
SULFIDES
SULFUR COMPOUNDS
THERMODYNAMIC PROPERTIES
THERMODYNAMICS
TRANSITION ELEMENT COMPOUNDS
VAPOR PRESSURE