Effect of aluminum additions on the thermodynamic and structural properties of LaNi/sub 5-x/Al/sub x/ hydrides

Journal Article · Mon Jan 01 04:00:00 EST 1979 · Adv. Chem. Ser.; (United States)

OSTI ID:5408573

Mendelsohn, M H; Gruen, D M; Dwight, A E

Desorption isotherms for the hydrides of LaNi/sub 4/ /sub 6/Al/sub 0/ /sub 4/ and LaNi/sub 4/ /sub 5/Al/sub 0/ /sub 5/ are presented and values for the enthalpy and entropy changes of the hydriding reactions are calculated from the van't Hoff plots of log P vs 1/T. A crystallographic model of LaNi/sub 4/Al is shown and consideration of the nearest neighbor atom distribution leads to a rationalization of the observed linear relationship between the enthalpy change, ..delta..H, and the aluminum composition. Brief discussions of methods to predict dissociation pressures or interstitial site occupation are included. The cubic and hexagonal AB/sub 5/ phases are compared and, finally, the application of these alloys in chemical heat pump systems is noted.

• Research Organization: Argonne National Lab., IL
• OSTI ID: 5408573
• Journal Information: Adv. Chem. Ser.; (United States), Journal Name: Adv. Chem. Ser.; (United States) Vol. 173; ISSN ADCSA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360104* -- Metals & Alloys-- Physical Properties
ALLOYS
ALUMINIUM ALLOYS
ALUMINIUM COMPOUNDS
ALUMINIUM HYDRIDES
ENTHALPY
ENTROPY
HEAT PUMPS
HYDRIDES
HYDROGEN COMPOUNDS
ISOTHERM
LANTHANUM ALLOYS
MATERIALS
NICKEL ALLOYS
PHYSICAL PROPERTIES
RARE EARTH ALLOYS
THERMODYNAMIC PROPERTIES