Composition and Thickness of Surface Layer on Molybdenum Tips for Scanning Tunnelling
نویسنده
چکیده
A combination of SEM, AES and angle-resolved XPS (ARXPS) has been applied to analyse the distribution of chemical compounds in the surface region of electrochemically etched molybdenum tips and to determine the contamination layer thickness. Carbon monoxide, graphite, molybdenum carbide and molybdenum oxide were found to be the main surface contaminants on molybdenum tips. Auger line profiling revealed a significant enrichment of carbon and oxygen upon the tip. The thickness of the oxygebcarbon contamination layer on the tip was estimated to be 135 & 1.0 nm as measured by AES. The thickness of the contamination layer on a molybdenum sheet was found to be 8.0 f 15 and 6.8 am using AES and ARXPS respectively. Quantitative analysis of the surface concentrations of carbon, oxygen and molybdenum has been performed.
منابع مشابه
Characterization of tungsten tips for STM by SEM/AES/XPS
For the first time, both X-ray Photoelectron Spectroscopy (XPS) and Auger Electron Spectroscopy (AES) techniques were applied in analysis of surface contamination of electrochemically etched Scanning Tunneling Microscope (STM) tungsten tips. Carbon monoxide, graphite, tungsten carbide and tungsten oxide were found as main surface contaminations of STM tungsten tips. The thickness of tungsten ox...
متن کاملInterfacial roughness effects on interlayer coupling in spin valves grown on different seed layers
We have studied the behavior of interlayer coupling in giant magnetoresistance spin valves as a function of seed layer composition and spacer layer thickness. Using in situ scanning tunneling microscopy, we have measured directly the roughness of the top surface of the lower ferromagnetic layer. We find that the seed layer composition is correlated to the roughnesses of the interfaces inside th...
متن کاملEffect of Surface Morphologies on the Isothermal Oxidation Behavior of MCrAlY Coatings Fabricated by High-velocity Oxyfuel Processes
In this study, the effect of surface morphologies on the isothermal oxidation behavior of MCrAlY coatings fabricated by high-velocity oxyfuel (HVOF) processes was investigated. To do so, free standing coatings with as-sprayed and polished surfaces were isothermally oxidized at 1050°C. The thickness of the bond coat was approximately 380μm. The Ra of the as-sprayed and polished surfaces were 6.4...
متن کاملSTUDY ON VANADIUM CARBIDE COATING FORMATION ON AISI L2 STEEL BY THERMO-REACTIVE DEPOSITION TECHNIQUE
Abstract: The possibility of vanadium carbide coating formation on AISI L2 steel was studied in molten salt bath containing 33 wt% NaCl- 67 wt% CaCl2. In this research, the effects of time, temperature and bath composition on growing layer thickness were studied. The vanadium carbide coating treatment was performed in the NaCl-CaCl2 bath at 1173, 1273 and 1373 K temperatures for 3, 6, 9 hours a...
متن کاملThe Effect of Time on the Formation & Growth of Passive Layer on Carbon Steel A516 Gr. 70 in Sour Water
A proposed method for protecting carbon steel and hence reducing iron release in an aqueous solution saturated with H2S is presented in this paper. The method is based on forming a stable and resistant sulfide layer (pyrite, FeS2, or pyrrhotite, Fe(1-x)S, phase or a mixture of both) on the carbon steel surface. The study on the formation of the sulfide layer was...
متن کامل