XPS and ToF‐SIMS characterization of a Finemet surface: effect of cooling

Abstract

The surface composition of amorphous Finemet, Fe 73 Si 15.8 B 7.2 Cu 1 Nb 3 , was studied by X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). The as-received sample in the original state and after Ar + sputter-cleaning was analyzed at room temperature as well as after cooling to −155°C. In the cooled state, the surface oxide layer composed of oxides of the alloy constituents was found to become enriched with elemental iron and depleted of elemental silicon, boron, oxygen and carbon as compared to the state at room temperature. Interaction of residual water vapor and hydrogen with the complex oxide layer occurring at low temperatures is believed to be responsible for the enhanced formation of surface hydroxides of the alloy constituents. The processes resulting in the observed redistribution of the elements on the surface of Finemet at low temperatures are discussed.

Facile synthesis of α-Fe2O3 hollow sub-microstructures, morphological control and magnetic properties

“…The peak at 533.6 eV may be formed by contributions from carboxyl groups O-CLO. 33 Fig. 2d shows the high-resolution XPS of C1s, the spectrum can be divided into three main peaks at 284.7, 286.1 and 288.2 eV.…”

XPS and ToF‐SIMS characterization of a Finemet surface: effect of heating

“…The species attribution has been discussed elsewhere. [7] The peaks of boron and copper were too small to be reliably identified and are not presented here.…”

“…The fitting parameters and constraints were the same as in our previous work. [7] The results of spectra deconvolution are given in Table 1. The species attribution has been discussed elsewhere.…”

Magnetic properties and macroscopic heterogeneity of FeCoNbB Hitperms

“…Some MHrelated effects impede the ordering at the surfaces. Probably the split of 59 Co hyperfine field of the akin ascast ribbon [15] together with the preference of Co for the amorphous remainder [4] is a hint here. Yet there are two points on the lacking correlation of amorphous 57 Fe /B hf S with the crystalline share: considering stronger exchange at the surfaces as signaled by higher-crystalline /B hf S there, one would still expect that the outweighing of the /B hf S decrease caused by relative Nb-enrichment produces rather smooth variation with A cr .…”

“…There is another candidate for as-cast heterogeneity of RQ metallic ribbons. It is a thin, complex oxide layer, which can be observed by XPS or similar spectroscopic methods [15]. The surface layer transforms at changing temperature and is also capable of affecting the ribbon's interior.…”