Strain and SiC particle formation in silicon implanted with carbon ions of medium fluence studied by synchrotron x-ray diffraction Strain stability of phosphorus doped pseudomorphically strained Si:C alloy is investigated via high-resolution X-ray diffractometry, Fourier transform infrared spectroscopy, and Hall measurement. Significant strain relaxations are found under post-annealing treatment far below b-SiC precipitation threshold temperature, especially for the highest phosphorus doped case. Most of the substitutional carbon is retained and no further b-SiC formation can be found for all samples investigated. Volume compensation through gettering of interstitial atoms around substitutional carbon is considered as a probable mechanism for the observed strain relaxation. The strain relaxation effect can be further reduced with HF treatment prior to post-annealing process. We found an upper limit for ion implant dose (<1 Â 10 14 atom/cm 2 ) for the retention of strain stability in phosphorus doped Si:C. V C 2014 AIP Publishing LLC. [http://dx.
The formation of multiple parallel twin boundaries at grain boundary grooves during Si solidification was investigated using an in situ observation system. Twin boundaries were repeatedly generated at a crystal/melt interface from a step-like grain boundary during solidification. The growth velocity of the micro-facet at the grain boundary groove accelerated and decelerated, which resulted in the nucleation of a twin and the development of a step-like structure at the grain boundary. The undercooling for multiple parallel twin formation as estimated based on experimental observation and the result was further discussed by comparison with previous studies.
The drop analyser, also termed the tensiograph, is an optical fibre-based instrument system for monitoring liquids. A comprehensive assessment of the drop analyser used as a UV-visible spectrophotometer has been undertaken employing both experimental and theoretical studies. A model of the tensiograph signal (tensiotrace) has been developed using a ray-tracing approach to accurately predict the form of the tensiotrace as an aid to drop spectroscopy. An analytical equation is derived for quantitative drop spectroscopy and the form of the equation has been experimentally tested. The equation applies to both the case of a growing drop and the situation in which the drop volume is held stationary. Measurements on both stationary and moving drops are of practical value. Modelling has been used to compute the average path length of the coupled light in the drop to give a result that compares favourably with values obtained from experimental measurements. An optimized method has been identified for quantitative drop spectroscopy measurements. Results from UV-visible studies on both pollutants in water and pharmaceuticals demonstrate the utility of this approach. Two key matters relating to the practicalities of drop spectroscopy are then discussed. Some experimental studies have been made to ascertain the practical limit in analyte concentration above which variations in transmitted light from the drop shape variations result. Here, tabulated information on a representative range of liquid types has been provided as a guide to optimized spectroscopic drop analysis. Secondly, the handling of micro-volume samples is discussed. The paper concludes with a brief evaluation of the usefulness of this drop spectroscopy approach, but specifically points to the importance of drop spectroscopy for nanoscience applications.
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