Floating zone refining of iron under reduced pressure with dynamic hydrogen flow

High purity iron was prepared by floating zone refining under reduced hydro gen pressure with dynamic hydrogen now. Commercial 99.999% iron was used as the starting material. The residual resistivity ratio and glow discharge m ass spectrometry were used for purity evaluation of zone-refined iron. The residual resistivity of the starting material was 1000 and that of zone ref ined iron was 11000. The Boating zone refining under dynamic hydrogen flow is efficient in removing gaseous elements and for the preparation of ultra high purity iron. The residual resistivity ratio values show good correspon dence with the chemical purity.