The performance of thin layers produced by molecular plating as α-particle sources

Sources for α-spectroscopy studies were prepared. Constant current density molecular plating was used to produce layers containing the α-particle emitter 147Sm. Different parameters of the molecular plating process were varied, namely the plating solvent (an isopropanol/isobutanol mixture, pyridine, and N,N-dimethylformamide), the applied deposition time (90, 180, and 360 min), and the surface roughness of the deposition substrate (ca. 10, 20, and 300 nm). Using different analytical techniques, Sm deposition yields, chemical composition of the produced surfaces, surface homogeneity, roughness and morphology were investigated. Alpha spectra were recorded with a Si solid-state detector for samples belonging to the different types of characterized sources, and big differences in the peak shape and position of the peak maximum were observed, as well as significant differences in the fraction of α particles reaching the detector positioned above the samples. An explanation for the observed features is presented. The results of these studies led to the identification of the key plating parameters, namely the plating solvent and the roughness of the deposition substrate, which most affect the quality of the α spectra.