A study of the mobility and trapping of minor hydrogen concentrations in diamond in three dimensions using quantitative ERDA microscopy

Two direct and two indirect nuclear methods are used for the analysis of hydrogen in diamond of different types. Exploiting the power of two-dimensional position sensitive detectors, the distribution of hydrogen in and on diamond in three dimensions has been measured by elastic recoil detection analysis, supplementing the earlier resonant nuclear techniques. Indirect methods of muonium spin rotation and time differential perturbed angular distribution measurements prove to be very informative. In a series of dynamic experiments, hydrogen has been implanted and the diffusion thereof sought as a function of temperature. Unlike the equivalent case for silicon, no migration of the hydrogen in diamond is found up to 1473 K. This striking result is considered in regard to existing theoretical calculations. It is concluded that the implanted hydrogen is self-trapped. Arguments are presented as to the location of hydrogen in natural diamond, in diamond grown at high pressure and high temperature, and in diamond grown by chemical vapour deposition.     

Scanning Kelvin probe force microscopy study of chromium nitrides in 2507 super duplex stainless steel—Implications and limitations

The effect of chromium nitrides on localized corrosion resistance of 2507 super duplex stainless steel was investigated in this study. The Volta potential difference measured with scanning Kelvin probe force microscopy (SKPFM) indicates that chromium nitrides with the size range of 80–230 nm precipitated isothermally at the ferrite/austenite phase boundaries may detrimentally affect the corrosion resistance due to the observed local Volta potential drop at the phase boundaries. Small quenched-in nitrides with the size range of 50–100 nm formed in the centre of the ferrite phase, on the other hand, may have small or no adverse effect on the corrosion resistance since they showed no difference in Volta potential relative to the matrix.