In this study, gamma irradiated NH4HCOO single crystal and CsHCOO powders w
ere investigated at room temperature. The species, produced by gamma irradi
ation was found to be CO2-, in NH4HCOO, and the principal values of g, and
the hyperfine coupling tensors of the unpaired electron with the C-13 nucle
us were obtained. In CsHCOO powders, the species was attributed to the CO3-
radical, and a superhyperfine interaction with the Cs-55 nucleus, of nucle
ar spin I = 7/2, has been observed, and this has been explained by the inte
raction of the unpaired electron with a nearby Cs-55 nucleus. The superhype
rfine constant was found to be approximate to 1 mT. (C) 1999 Elsevier Scien
ce B.V. All rights reserved.