Nonstoichiometric wüstite (001) surface exposing defect clusters

Abstract

The (001) surface of nonstoichiometric wüstite (Fe0.94O) grown by the floating zone technique was investigated using STM, LEED and AES. Two distinctive structures, i.e., the dents arrangement and the FeO(001)-c(4×2) reconstructed structure coexist on the terrace after annealing at 1 073 K in the ultrahigh vacuum (UHV) system. On the other hand, the only dents exist after annealing at 1 273 K. The dent is the Fe vacancy pair in the rocksalt-type FeO(001)-(1×1) matrix, which is the exposed P' phase of the defect cluster due to nonstoichiometry. © 2011 ISIJ.