Chemical state

About: Chemical state is a research topic. Over the lifetime, 2378 publications have been published within this topic receiving 78183 citations.

Chemical state of nitrogen in a high nitrogen face-centered-cubic phase formed on plasma source ion nitrided austenitic stainless steel

Abstract: A single high nitrogen face-centered-cubic phase (γN) was formed on the plasma source ion nitrided 1Cr18Ni9Ti (18-8 type) austenitic stainless steel. Auger electron spectroscopy and x-ray photoelectron spectroscopy, in conjuction with ion beam sputtering, were used to determine the chemical composition and bonding of nitrogen in the γN phase. The chemical composition of the γN phase was shown as a formula with atomic fraction (Fe0.60,Cr0.22,Ni0.18)2N. The γN phase possessed weaker Cr–N ionic-type bonds and stronger Fe–N ionic-type bonds, compared with the stoichiometric nitrides. The Cr2p3∕2 binding energy was 1.1eV lower than that of CrN and Cr2N phases (at 575.5eV). The chemical shift of the Fe–N bonding compared with the Fe–Fe bonding was nearly 2.1eV. The N1s binding energies showed that the nitrogen was in the chemical state with iron (at 396.6eV) and chromium (at 397.7eV). All the chromium appeared to be in the Cr–N bond. A part of iron was also observed in the nitride state, and all the nickel was ...

Surface chemical changes induced by low-energy ion bombardment in chromium nitride layers

Abstract: In this work three types of CrN x layers-one close to Cr 2 N, the other to CrN and a third with high nitrogen content CrN 1+x - were prepared by reactive magnetron sputtering. The samples were subjected to bombardment by Ar + and N 2 + ions applied in sequence. The relative atomic concentration and the chemical states of the elements in the surface layer were determined by x-ray photoelectron spectroscopy. Alternate bombardment with Ar + and N 2 + ions (1-2 keV) resulted in significant compositional and chemical state changes. Although prolonged Ar + bombardment did not decrease the nitrogen content of Cr 2 N below the nominal (CrN 0.5 ) composition, it decreased the nitrogen content of the closely stoichiometric CrN appreciably, to about CrN 0.8 . At bombardment with N 2 + ions nitrogen could be implanted into the Cr 2 N films, changing its composition up to about CrN 0.8 . It was shown that extra nitrogen could be incorporated also into the CrN samples, increasing the nitrogen content above the stoichiometric composition up to about CrN 1.2 . The CrN 1+x -type sample showed high stability towards Ar + bombardment. Two significantly different chemical states of nitrogen were determined for the two types of nitrides: the N is peak at 397.5 ± 0.1 eV binding energy was characteristic of N in Cr 2 N and the peak at 396.5 ± 0.1 eV of N in the CrN state. The effect of Ar + and N 2 + bombardment on the surface composition discussed in this paper may provide information for elaboration of deposition conditions for CrN x coatings with predetermined chemical composition and structure.

Tuning the Chemical State of Silver on Ag─Mn Catalysts to Enhance the Ozone Decomposition Performance

Abstract: Ag–Mn catalysts with excellent water resistance and ozone decomposition activity were successfully synthesized by simple precipitation and impregnation methods. Under a relative humidity of 65% and...