A vapor-pressure study of the systems formed by polonium with palladium and iridium

Journal Article · Fri Nov 01 00:00:00 EST 1985 · Sov. Radiochem. (Engl. Transl.); (United States)

OSTI ID:6014139

Abakumou, A S; Khokhlou, A D; Malysheu, M L; Reznikova, N F

Direct thermal vacuum synthesis shows that polonium vapor does not react with iridium when they are heated together to 1000/sup 0/C. Polonium vapor begins to be absorbed appreciably by palladium at 340-350/sup 0/C. The radiotensimetric method has been used in examining the thermal stabilities of polonium-palladium comounds, which has shown that there are three intermetallides PdPo, Pd/sub 2/Po, and Pd/sub 3/Po, which dissociate to release elemental polonium. The dissociation temperature increases as the polonium content of the compound decreases and is in the range 390-700/sup 0/C. The temperature dependence of the polonium vapor pressure in the dissociation is described by the following: PdPo log P /SUB Pa/ = (7.31 + or - 0.08) -- (4520 + or -40)/T, and at 460580/sup 0/C, ..delta..H = 86.3 + or - 0.7 kJ/mol; Pd/sub 2/Po log P /SUB Pa/ = (7.42 + or - 0.01) -- (6080 + or 10)/T at 725900/sup 0/C, ..delta..H = 116 + or - 0.2 kJ/mol; Pd/sub 3/Po log P /SUB Pa/ = (9.18 + or - 0.01) -- (8620 + or 1000/sup 0/C, ..delta..H = 164 + or - 1 kJ/mol. The properties of these compounds are compared with those of the corresponding tellurides and of the polonium-nickel and poloniumplatinum systems.

• OSTI ID: 6014139
• Journal Information: Sov. Radiochem. (Engl. Transl.); (United States), Vol. 27:2; Other Information: Translated from Radiokhimiya, Vol. 27, No. 2, pp. 210-216, March-April, 1985
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
IRIDIUM COMPOUNDS
DISSOCIATION
VAPOR PRESSURE
PALLADIUM COMPOUNDS
POLONIUM COMPOUNDS
CHEMICAL REACTION KINETICS
COMPARATIVE EVALUATIONS
HIGH TEMPERATURE
INTERMETALLIC COMPOUNDS
IRIDIUM
MEDIUM TEMPERATURE
NICKEL
PALLADIUM
PLATINUM
POLONIUM
RADIOCHEMISTRY
SYNTHESIS
TELLURIDES
TEMPERATURE DEPENDENCE
VERY HIGH TEMPERATURE
ALLOYS
CHALCOGENIDES
CHEMISTRY
ELEMENTS
KINETICS
METALS
PHYSICAL PROPERTIES
PLATINUM METALS
REACTION KINETICS
REFRACTORY METAL COMPOUNDS
TELLURIUM COMPOUNDS
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
400201* - Chemical & Physicochemical Properties
400700 - Radiochemistry & Nuclear Chemistry