Studies of layered uranium(VI) compounds. V. Mechanisms of densification of hydrogen uranyl phosphate tetrahydrate (HUP): pressure-induced planar glide and solution phase sintering

Journal Article · Wed Oct 01 00:00:00 EDT 1980 · J. Solid State Chem.; (United States)

DOI:https://doi.org/10.1016/0022-4596(80)90432-6· OSTI ID:6695945

Childs, P E; Howe, A T; Shilton, M G

The good proton conductor HUO/sub 2/PO/sub 4/.4H/sub 2/O (HUP) can be easily fabricated into disks or films suitable for use in electrochromic displays, fuel cells, or batteries. Kinetic studies of the room-temperature densification reveal the presence of two mechanisms. At applied pressures of 20 MN m/sup -2/ the observed rapid densification was attributed to the gliding of the structural layers over each other to achieve essentially 100% of the theoretical density. When the powder had been wettened by solution, slow sintering occurred even in the absence of applied pressure, and we attribute this to a solution-phase sintering mechanism. The study is one of the few to be reported on platelet-shaped crystals rather than the usual spherical-shaped particles. This fact, together with the ease of cleavage of the layers, largely accounts for the excellent fabrication properties. The optimum conditions for pressing large clear robust disks are described.

• Research Organization: Univ. of Leeds, England
• OSTI ID: 6695945
• Journal Information: J. Solid State Chem.; (United States), Vol. 34:3
• Country of Publication: United States
• Language: English

Related Subjects

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
URANYL PHOSPHATES
PRESSING
USES
COMPACTING
CRYSTALS
DENSITY
ELECTRIC BATTERIES
FILMS
FUEL CELLS
HYDRATES
LAYERS
POWDERS
SINTERING
SOLID ELECTROLYTES
SOLUTIONS
ACTINIDE COMPOUNDS
DIRECT ENERGY CONVERTERS
DISPERSIONS
ELECTROCHEMICAL CELLS
ELECTROLYTES
FABRICATION
MATERIALS WORKING
MIXTURES
OXYGEN COMPOUNDS
PHOSPHATES
PHOSPHORUS COMPOUNDS
PHYSICAL PROPERTIES
URANIUM COMPOUNDS
URANYL COMPOUNDS
400702* - Radiochemistry & Nuclear Chemistry- Properties of Radioactive Materials