Anion exchange for the ultra-high purification of transition metals

Most of the 3d-type transition metals have long been staple materials in industry. The advent of modern electronics has brought about a dynamically increasing need for a number of transition metals at an extremely high level of purity. Fields of application include materials for conductors, IC bonding, high-fidelity signal transmission (like Cu), new compound-type semiconductors, opto-electronic devices (like Fe and Zn) and thin films with special magnetic or magneto-optic properties (like Cr, Co and Fe).