Sublimation thermodynamics of the URu/sub 3/ compound

Journal Article · Tue Jul 15 04:00:00 EDT 1980 · J. Chem. Phys.; (United States)

OSTI ID:5349252

Edwards, J G; Starzynski, J S; Peterson, D E

The sublimation behavior of the URu/sub 3/ intermetallic compound has been studied with a mass spectrometer--target collection apparatus. The sublimation reaction proceeded by dissociation to the elements up to the solidus temperature of the condensed phase. Vapor pressures of gaseous /sup 233/U effusing from the Knudsen cell over the temperature range 1690--2100 K were measured by target collection and radioanalysis of the targets. A second-law treatment of the data yielded ..delta..H/sup 0/ (1896 K) and ..delta..S/sup 0/ (1896 K) of sublimation of 563.4 +- 13.4 kJ mole/sup -1/ (134.6 +- 3.2 kcal mole/sup -1/) and 147.8 +- 7.1 JK/sup -1/ mole/sup -1/ (35.3 +- 1.7 cal K/sup -1/ mole/sup -1/), respectively. The corresponding ..delta..H/sup 0/ (1896 K) and ..delta..S/sup 0/ (1896 K) of formation were -79.5 +- 20.9 kJ mole/sup -1/ (-19.0 +- 5.0 kcal mole/sup -1/) and -35.2 +- 10.5 JK/sup -1/ mole/sup -1/ (-8.4 +- 2.5 cal K/sup -1/ mole/sup -1/), respectively. Third-law treatment with estimated free energy functions yielded ..delta..H/sup 0/ (298 K) of sublimation and ..delta..H/sup 0/ (298 K) of formation of 572.2 +- 8.0 kJ mole/sup -1/ (136.8 +- 1.9 kcal mole/sup -1/) and -49 +- 22 kJ mole/sup -1/ (-12 +- 5 kcal mole/sup -1/),respectively.

• Research Organization: Department of Chemistry, University of Toledo, Toledo, Ohio 43606
• OSTI ID: 5349252
• Journal Information: J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 73:2; ISSN JCPSA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102* -- Metals & Alloys-- Structure & Phase Studies
ACTINIDE ALLOYS
ALLOYS
ENERGY
ENTHALPY
EVAPORATION
FORMATION HEAT
FREE ENERGY
INTERMETALLIC COMPOUNDS
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES
PLATINUM METAL ALLOYS
REACTION HEAT
RUTHENIUM ALLOYS
RUTHENIUM BASE ALLOYS
SUBLIMATION
SUBLIMATION HEAT
THERMODYNAMIC PROPERTIES
TRANSITION HEAT
URANIUM ALLOYS
VAPOR PRESSURE