New matrix for the 'ageless' 21.6-keV (sup 151)Eu nuclear gamma ray Moessbauer source

摘要

Moessbauer spectroscopy has been used over the past two decades to advance the study of europium compounds and alloys, primarily utilizing the 21.6-kev gamma ray emitted from beta decaying (sup 151)Sm. This isotope, which has a 87 year half-life, has been used in either a samarium fluoride (SmF(sup 3)) or samarium oxide (Sm(sub 2)O(sub 3)) matrix. We now report a study involving, europium oxalate decahydrate (Eu2(C(sub 2)O(sub 4))(center dot)10H(sub 2)O), europium fluoride EuF(sub 3) and EuBe(sub l3) as absorbers at known thicknesses. Our data supports the view that Sm(sub 2)(C(sub 2)O(sub 4))(sub 3)(center dot)H(sub 2)O will provide a better source matrix than either the fluoride or oxide due to the narrower linewidth and comparable ''f'' factor to (sup 151)SmF(sub 3).