SIMS/XPS characterization of surface layers formed in 3 mass% Si‐steel by annealing in oxygen at low partial pressure

Abstract

Selective oxidation in silicon steel shows several interesting phenomena, such as the formation of an internal oxidation zone that depends on the oxidation conditions and the steel composition. In this work, SIMS and XPS were used for characterizing the formation processes of surface layers formed during selective oxidation of a typical silicon steel. The starting material is a secondary-recrystallized 3 mass% Sisteel sheet with a surface orientation of (011). Sample sheets were annealed at a temperature of 948-1023 K under an atmosphere with a low partial pressure of oxygen. The SIMS depth profiles show that the internal oxidation zone thickens and an iron-rich layer that formed on the internal oxidation zone expands as the annealing temperature increases. Manganese and chromium levels increase outside the internal oxidation zone, whereas tin exists in the internal oxidation zone. The XPS results of the sample surface show that silicon and manganese levels increase on the sample surface to form oxides, and the chemical composition and state of these elements depend on the annealing temperature. In addition, tin increases on the surface of a relatively thick iron-rich layer that formed on the internal oxidation layer. These experimental results are discussed on the basis of the thermodynamic characteristics of the elements.

Gold Penetration Correlated with Selective Oxidation of Silicon in Fe-3 mass%Si Single Crystal

“…The profiles show that the selective oxidation of silicon occurs in a surface layer in which the iron ion counts decreases, as observed in previous works; 4,7) e.g. in the sputtering time between about 100 s and 600 s for the sample annealed at 948 K. An increase in tin ion counts is observed in the surface layer containing silicon oxides, indicating the fact that tin is one of active elements at surface and interface in Fe-3 mass%Si.…”

“…Au XPS peaks are little detected in this spectrum, showing that its surface composition is comparable to that in a sample annealed in a similar condition. 7) This indicates that deposited gold is diffused into a surface layer of the sample. In order to compare a SIMS depth profile of gold in Fe-3 mass%Si with the iron case, pure iron samples annealed under the identical condition were also prepared.…”

Characterization of surface oxide layers formed on FeAl alloys by annealing under different atmospheres

“…[11,12] Formation of aluminum oxide on the alloy surface A reactive element in a surface layer is distributed by the selective oxidation of the element, which is related to the mobility of the element in the alloy matrix. [8,11] Therefore, the kinetics of the formation of Al 2 O 3 layers on the sample surfaces should be discussed on the basis of the mobility of aluminum in the ironbased alloys. The process of the formation of the Al 2 O 3 layer may be considered to be due to the outward diffusion process of Al in the matrix.…”

Improvement of Oxidation Resistance of an Fe–Mn–Si–Cr Shape Memory Alloy by Annealing under Vacuum

“…SIMS measurements were carried out using an apparatus with quadrupole-type mass spectrometer. 7) An incident beam of 5.0 keV Cs þ ions was irradiated onto a sample, and positive secondary ions were counted. XPS measurement was carried out for analyzing the chemical composition of a few nanometers of the surface layer.…”

“…6) The XPS spectra were taken by monochromated incident Al-K . 7) In addition, the structure and crystallographic orientation of the surface layer was analyzed by electron backscattering pattern (EBSP). The results were shown in the orientation image (OIM) of face centered cubic (fcc) or body centered cubic (bcc) phases.…”