Comparison of the decay constants of 51 Cr with metal, oxide, and chromate chemical states

Chromium-51 decays through electron capture, the probability of which is perturbed by its electronic state. We have precisely measured the decay constants ( λ ) of 51 Cr with metal (Cr 0 ), oxide (Cr 3+ ), and chromate (Cr 6+ ) to investigate the effects of chemical states on the decay constants of 51 Cr. The value of {λ( Cr^ 6 + ) - λ( Cr^ 0)}/ . -0ptλ( Cr^ 0) was determined to be (6.4 ± 3.7) × 10 −4 , whereas the difference less than 1.4 × 10 −4 was observed for {λ( Cr^ 3 + ) - λ( Cr^ 0)}/ . -0ptλ( Cr^ 0) .