K alpha xps

The starting ND powders were characterized by transmission electron microscopy (TEM) using a JEOL 2500 TEM operating at 200 keV in order to assess the size of the ND particles. ND powders were dispersed into a methanol solution via ultrasonication and then a drop of the dispersion was deposited onto a lacy carbon TEM grid. An FEI Scios dual-beam focused ion beam – scanning electron microscope (FIB-SEM) was utilized to characterize the powders, consolidated microstructures, and wear track morphologies. WC particle sizes were analyzed using Image J software. Energy dispersive spectroscopy (EDS) analysis was conducted on an FEI Scios FIB-SEM equipped with an Oxford EDS system to characterize the elemental composition of phases present on wear tracks. Phases in the sintered samples and corresponding wear tracks were analyzed using a Scintag XDS2000 X-ray diffractometer. The operating voltage and current were 45 kV and 40 mA, respectively. Surface chemistry of the sintered samples and corresponding wear tracks was analyzed via X-ray photoelectron spectroscopy (XPS) using a Thermo Scientific K-alpha XPS. The density of sintered samples was measured using the Archimedes method, and relative densities were calculated based on the known densities of WC-Co and ND. WC particle sizes were measured using Image J software; averages presented are based on over 100 measurements.

XPS analyses of MnO₂ nanoflowers were carried out by a Thermo Scientific K‐Alpha XPS with Al K‐alpha monochromatic radiation (1486.3 eV). For XPS measurements, dried samples were exposed to 400 µm X‐ray spot size and 50.0 eV pass energy. The experimental pressure and the base pressure were kept below about 1 × 10⁻⁷ and 3 × 10⁻⁹ mbar, respectively. The C 1s peak at 285.0 eV was designated for the assessment.

XPS spectra were recorded using a Thermo Scientific K –alpha XPS with monochromatic Al Kα X-ray source (1486.7 eV) with a vacuum maintained at 5 × 10⁻⁹ torr. The XPS survey spectra were recorded at 200 eV pass energy, 1.0 eV/step. The high-resolution spectra of the individual elements were recorded by accumulating 20 scans at 50 eV pass energy and 0.1 eV/step. The sample measurements were performed at 400 μm spot. Data analysis and curve fitting were performed using origin software (origin lab corporation, Northampton, MA, USA).