Selected Area Electron Diffraction Study of Twinned α-Fe[sub 2]O[sub 3] Bladelike Platelet Growths on Iron

Abstract

The structure of bladelike platelets formed on iron at 450 °C in atmospheres containing both water vapor and a trace of oxygen was studied. Single crystal electron diffraction patterns show the blade axis to be . The collection of all of the patterns indicates a structure of twinned crystals whose orientations are related by mirroring on the blade face plane, . Arguments are presented in favor of a growth mechanism involving the diffusion of iron atoms or ions along the twin interface to the tip, where reaction occurs with oxygen.