Ion beam lithography for Fresnel zone plates in X-ray microscopy

Fresnel Zone Plates (FZP) are to date very successful focusing optics for X-rays. Established methods of fabrication are rather complex and based on electron beam lithography (EBL). Here, we show that ion beam lithography (IBL) may advantageously simplify their preparation. A FZP operable from the extreme UV to the limit of the hard X-ray was prepared and tested from 450 eV to 1500 eV. The trapezoidal profile of the FZP favorably activates its 2nd order focus. The FZP with an outermost zone width of 100 nm allows the visualization of features down to 61, 31 and 21 nm in the 1st, 2nd and 3rd order focus respectively. Measured efficiencies in the 1st and 2nd order of diffraction reach the theoretical predictions

DETERMINATION OF PHENYLBUTAZONE AND OXYPHENBUTAZONE IN BOVINE PLASMA USING HIGH PERFORMANCE LIQUID CHROMATOGRAPHY WITH UV DETECTION

Abstract A simple and reliable method for the determination of phenylbutazone (PB) and its active metabolite oxyphenbutazone (OPB) in bovine plasma is described. After solvent extraction of plasma samples with acetonitrile and clean-up by solid phase extraction using C18 cartridges, analytes were determined by liquid chromatography with UV detection. Mean recovery values of PB and OPB from plasma samples fortified at the levels of 30-480 ng/ml were 52.0±7.0% and 69.0±7.8%, respectively. Repeatability, expressed as coefficient of variation, was below 15%. Limit of detection for PB was 18 ng/ml and for OPB -12 ng/ml. Limit of quantitation of PB and OPB was 60 ng/ml each. Validation parameters and calculated performance criteria: decision limit (CCα) and detection capability (CCβ) indicate that the method is suitable for screening plasma samples for phenylbutazone and oxyphenbutazone

Mechanism of recrystallization process in epitaxial GaN under dynamic stress field - Atomistic origin of planar defect formation

The mechanism of recrystallization in epitaxial (1000) GaN film, introduced by indentation technique, is probed by lattice dynamic studies using Raman spectroscopy. The recrystallized region is identified by Micro-Raman area mapping. Pop-in bursts in loading lines indicate nucleation of dislocations and climb of dislocations. These processes set in plastic motion of lattice atoms under stress field at the center of indentation for the initiation of recrystallization process. A planar defect migration mechanism is evolved. A pivotal role of vacancy migration is pointed out, for the first time, as the rate limiting factor for the dislocation dynamics initiating the recrystallization process in GaN.Comment: 17 pages, 5 figures including Supplements, Accecepted in J. Raman Spectroscop