Speaker
Prof.
Viacheslav Radchenko
(JSC "State Scientific Center - Research Institute of Atomic Reactors")
Description
Over many years JSC “SSC RIAR” has been performing activities on the production and in-vestigation of metals of transplutonium elements (TPE), their alloys and compounds.
This paper presents the results of production and radiographic examination of micro-samples of curium-244 compounds with ion, cobalt and carbon, namely an identification of crystal lattices of the compounds obtained and calculation of crystal lattice parameters, study on the effect of inten-sive alpha-decay on crystal structures of intermetallides and carbides.
Samples of the Cm-Co, Cm-Fe and Cm-C systems were prepared by high temperature con-densation of metal curium vapor onto corresponding substrates. In the Cm-C sample such a “sub-strate” represents a thin amorphous carbon layer applied preliminary onto a flat iridium plate. The radiographic examination results of the produced compounds are presented in the table below.
Table
Crystal lattice parameters of phases detected during investigation of the Cm-Fe, Cm-Co and Cm-C systems.
System Phase Lattice Lattice parameters
a, Å c, Å V, Å3
Cm-Co Сo17Cm2 Hexagonal (P63/mcm) 8,378(7) 8,070(5) 491(1)
Co5Cm Hexagonal (P6/mmm) 4,88(1) 4,08(4) 84(1)
Co2Cm Cubic (Fd3m) 7,242(2) - -
Cm-Fe Fe17Cm2 Hexagonal (P63/mmc) 8,406(3) 8,122(2) 497,0(5)
Fe2Cm Cubic (Fd3m) 7,213(2) - -
Cm-C Cm2C3 Cubic ( )
8,3904(5) - -
Cm3C FCC 5,172(2) - -
Note. In the column “Lattice” a lattice spatial group is indicated in brackets. V – is volume of a crystal lattice elementary cell. Definition errors of the last character are given in brackets after the lattice parameter values.
In the Cm-Co system three intermetallic compounds were detected: Co17Cm2 (hexagonal lat-tice of spatial group P63/mcm), Co5Cm (hexagonal lattice of spatial group P6/mmm) and intermetal-lide Co2Cm (cubic lattice of spatial group Fd3m). Cadmium did not show any solubility in - and -Со at room and elevated temperature.
In the Cm-Fe system two intermetallic compounds were detected: Fe17Cm2 (hexagonal lat-tice of spatial group P63/mcm ) and Fe2Cm (cubic lattice of spatial group Fd3m). This system did not show mutual solubility of its components at room temperature. The effect of high alpha-activity of 244Cm nuclide on the crystal structure of intermetallide Fe2Cm was demonstrated.
In the Cm-C system carbides Cm2C3 and Cm3С with a cubic lattice were detected, which were isostructural with regard to carbides Am2C3 and Sm3С. Crystal lattice parameters of the cu-rium carbides were calculated and data on their x-ray amorphization induced by intensive 244Cm decay were obtained.
Primary author
Prof.
Viacheslav Radchenko
(JSC "State Scientific Center - Research Institute of Atomic Reactors")
