[en] The conditions for production of radioactive ion-beams from targets of refractory metals by addition of CF₄ gas have been investigated. The production yields of chemically pure mass separated beams, obtained through the formation of molecular ions, are described for the elements Ca, Sc, Sr, Y, (Zr), Ba, Lu, and Hf. Improved release properties are obtained for several elements, owing to the formation of volatile chemical compounds in the target. Production yield curves are presented, and applications to other targets and elements are briefly discussed. (orig.)