Examination was made of the optimum performance of thermal ionization, field ionization and electron ionization sources, using permalloy (Ni 81 Fe 19 ) and aluminium as source materials. Discussion is made of the possible use of these to give direct deposition sources, for low-cost nanoscale device production. Fabrication of field emitter tips using focused ion beam milling was used to try to enhance the ion emission current of field ionization sources. Electron ionization produced the largest ion current, but field ionization gave enhanced stability.