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An Investigation of Transmutation Effects in Crystalline Solids
Author(s) -
Wittels M. C.,
Stiegler J. O.,
Sherrill F. A.
Publication year - 1964
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.19640040308
Subject(s) - nuclear transmutation , materials science , nucleation , alloy , single crystal , neutron diffraction , crystallography , analytical chemistry (journal) , x ray crystallography , diffraction , crystal structure , neutron , chemistry , metallurgy , nuclear physics , physics , organic chemistry , optics , chromatography
X‐ray diffraction, electron diffraction and microscopy, metallography, and thermal methods were utilized to study transmutation effects in a group of crystalline solids. Nearly homogeneous distributions of transmuted species were introduced into small single crystals of Au 197 , Ag 107 , and In 115 , and power samples of Ir 193 , In 2 115 O 3 , and Lu 2 176 O 3 . The crystals were irradiated in a thermal neutron flux of 4.0 × 10 14 neutrons/cm 2 s at a temperature of ∼ 85 °C for periods of a few days to several months so that considerable fractions of transmuted species were formed. Small metal single crystal spheres were converted to alloy single crystals in their solid solution ranges at temperatures up to several hundred degrees below those required by normal laboratory methods in Au 0.82 Hg 0.18 , Ag 0.78 Cd 0.22 , and In 0.95 Sn 0.05 . A powder sample of Ir 193 was transformed into the solid solution alloy Ir 0.68 Pt 0.32 , a high temperature alloy, which would require a temperature in excess of 2000 °C for its formation by laboratory methods. The production of 22.5 at.% Hg 198 and Hg 199 in Au 197 through nuclear transmutation revealed the nucleation of Au 3 Hg particles with the hcp structure, while the introduction of 29 at.% caused a recrystallization into two unidentified phases. Long range order in single crystals of In 115 was completely destroyed when 14 at.% Sn 116 was introduced through nuclear transmutation. Powder specimens of In 2 O 3 enriched in In 115 were irradiated to produce concentrations of Sn 116 as high as 38 (metal) at.% with the result that a new phase with a smaller fluorite structure was formed which contains oxygen vacancies. The original In 2 O 3 structure was largely recovered upon annealing at 1200 °C and SnO 2 particles were precipitated. Powder samples of Lu 2 O 3 containing Lu 176 were irradiated to produce 74 (metal) at.% Hf 177 and the resultant material was cubic (fluorite) with a lattice parameter approximately one‐half that of the original structure. This oxygen deficient lattice was stable at temperatures up to 1200 °C. The results are considered in terms of the original crystal structures and known phase equilibrium systems, and possible future experiments are discussed.