Development and implementation of holmium sources produced by molecular plating for the HOLMES experiment

This manuscript reports on the optimization of a molecular plating procedure for the production of uniform and homogeneous films of holmium deposited onto gold-plated copper substrate. In particular, the effects caused by molecular plating solvents with different vapour pressure on the morphology and stability of the resulting films were investigated, allowing the selection of the optimum solvent. The developed procedure will allow allow the production of sources of holmium ions for the envisaged HOLMES experiment aiming at the direct measurement of the neutrino mass.