Effect of an external electric field on the decay constant of 99Tcsup(m) in Halogen complexes

Abstract A positive change Δλ/λ of the decay constant of 99 Tc m has been observed on the application of an external electric field in K 2 TcX 6 (X = F, Cl, Br, I). For its investigation the Tc‐complexes were embedded as small conglomerates or more or less as isolated single molecules in a powder of high dielectric constant, which was then compressed into a thin layer of about 0.2 mm and inserted between two capacitor plates. The change Δλ/λ depends on the strength of the chemical bond of 99 Tc m . As a first approximation Δλ/λ was assumed to be linearly dependent upon the electric field. The experimental results with an external field of 10 4 V/cm are: magnified image A relationship between Δλ/λ and the electro‐negativities of the ligand atoms could be established. Difficulties encountered in the theoretical calculation of Δλ/λ are discussed.