nickel oxide powder (NiO) is produced by pyrolyzing NiO compounds in oxygen or water to form light green powder. It is used for a variety of specialty coatings and sensor applications, as well as in the production of electronics.
High purity, spray dry nickel oxide powder for use in sputtering targets and other applications at room temperature or below with various sputtering processes including Thermal and Electron Beam Evaporation (EBE), Low Temperature Organic Evaporation (LTOE), Atomic Layer Deposition (ALD), Physical Vapor Deposition (PVD) and Chemical Vapor Deposition (CVD). This powder has the smallest average grain sizes available.
Release of nickel from nickel oxide powder is not proportional to the bulk alloy composition and is governed by surface oxide characteristics and composition as well as particle size, solution and agglomeration. Hence, these particles cannot be considered a reliable indicator of nickel behavior.
Differences in particle characteristics and surface composition were investigated for two different nickel metal powders containing thin outer surface oxides (shells). The outermost surface of both was analyzed by means of XPS.
The XPS spectra were acquired using an UltraDLD spectrometer from Kratos Analytical, Manchester, UK. Spectra were acquired with a monochromatic Al Ka X-ray source (1486.6 eV) operated at 300 W.
The XPS spectra reveal significant differences in the outermost surface composition of the Ni metal powders. The Ni (N13) powder contains a thinner oxide of NiO, and the Ni (N36) powder has a thicker surface oxide of NiO covered with Ni(OH)2. These differences can explain the observed significantly lower extent and longer time dependence of released nickel in ALF for the Ni (N13) powder compared with the Ni (N36) powder.