Phase Diagrams

· The photograph shows this method being applied to a titanium polycrystalline rod that is being heated by electron bombardment from the loop cathode surrounding the sample.
· The liquid zone is held in place by surface tension forces, and it is unnecessary to have the sample in touch with a container during the refining process.
· The floating zone prevents transfer of impurities from the container to the sample and permits reaching impurity levels of 1 in 10⁸.

From: Pfann, Zone Refining, Scientific American 217 (1967) 63