Structural and mechanical properties of W-C: H coatings prepared by HiTUS

The structure and mechanical properties of hydrogenated tungsten-carbon (W-C: H) coatings have been studied as a function of the composition and structure. These coatings were prepared by the High Target Utilization Sputtering (HiTUS), the first time used for this type of coatings. W-C: H coatings were deposited from tungsten–carbide target in argon, argon–acetylene (C2H2), and argon–methane (CH4) atmosphere on bearing steel 100Cr6 substrate, Al substrate, Si wafer a, and WC-Co substrate. W-C: H coatings obtained at different acetylene and methane flow were characterized by Elastic Recoil Detection Analysis (ERDA) and Rutherford Backscattering (RBS), X-ray diffraction, Transmission electron microscopy (TEM), and nanoindentation. Mechanical properties of these coatings are controlled within a range through a change in mutual concentration of crystalline phase and amorphous hydrogenated carbon matrix. The higher hardness (Hit = 29.5 ± 4.5 GPa) was measured for coating with 3 sccm methane addition. W-C: H coatings with more than 4 sccm of C2H2 and CH4 addition had fully amorphous structure and worse off mechanical properties.

Time-Of-Flight ERDA for Depth Profiling of Light Elements

The time-of-flight elastic recoil detection analysis (TOF-ERDA) method is one of the ion beam analysis methods that is capable of analyzing light elements in a sample with excellent depth resolution. In this method, simultaneous measurements of recoil ion energy and time of flight are performed, and ion mass is evaluated. The energy of recoil ions is calculated from TOF, which gives better energy resolution than conventional Silicon semiconductor detectors (SSDs). TOF-ERDA is expected to be particularly applicable for the analysis of light elements in thin films. In this review, the principle of TOF-ERDA measurement and details of the measurement equipment along with the performance of the instrumentation, including depth resolution and measurement sensitivity, are described. Examples of TOF-ERDA analysis are presented with a focus on the results obtained from the measurement system developed by the author.

Micro-combinatorial sampling of the optical properties of hydrogenated amorphous $$\hbox {Si}_{1-x}\,\hbox {Ge}_{{x}}$$ for the entire range of compositions towards a database for optoelectronics

The optical parameters of hydrogenated amorphous a-$$\hbox {Si}_{1-x}\,\hbox {Ge}_{{x}}$$ Si 1 - x Ge x :H layers were measured with focused beam mapping ellipsometry for photon energies from 0.7 to 6.5 eV. The applied single-sample micro-combinatorial technique enables the preparation of a-$$\hbox {Si}_{1-x}\,\hbox {Ge}_{{x}}$$ Si 1 - x Ge x :H with full range composition spread. Linearly variable composition profile was revealed along the 20 mm long gradient part of the sample by Rutherford backscattering spectrometry and elastic recoil detection analysis. The Cody-Lorentz approach was identified as the best method to describe the optical dispersion of the alloy. The effect of incorporated H on the optical absorption is explained by the lowering of the density of localized states in the mobility gap. It is shown that in the low-dispersion near infrared range the refractive index of the a-$$\hbox {Si}_{1-x}\,\hbox {Ge}_x$$ Si 1 - x Ge x alloy can be comprehended as a linear combination of the optical parameters of the components. The micro-combinatorial sample preparation with mapping ellipsometry is not only suitable for the fabrication of samples with controlled lateral distribution of the concentrations, but also opens new prospects in creating databases of compounds for optical and optoelectonic applications.

In-situ measurements of magmatic volatile elements, F, S, and Cl, by electron microprobe, secondary ion mass spectrometry, and heavy ion elastic recoil detection analysis

Electron probe and ion probe are the two most used instruments for in situ analysis of halogens in geological materials. The comparison of these two methods on widely distributed glass standards (example: MPI-DING glasses, Jochum et al., G-cubed, 2006) provides a basis for establishing laboratory method, independent geochemical data sets for these elements. We report analyses of F, S, and Cl concentrations in three geological glass samples (EPMA) and 10 referenced standards (EPMA and SIMS). Furthermore, F and Cl absolute abundances have been determined independently for three of the standards (KL2-G, ATHO-G, and KE12), via heavy ion elastic recoil detection analysis (HIERDA), to certify the accuracy of the cross-calibration EPMA-SIMS. The detection limits for EPMA are a 150 μg·g-1 for F, 20 μg·g-1 for S and Cl, and for SIMS < 48 μg·g-1 for F, < 3 μg·g-1 for S, and <19 μg·g-1 for Cl. On SiO2-rich glass-standards, F and Cl measurements by HIERDA highlight a weak matrix effect during SIMS analysis of F and Cl. With the HIERDA independently measured value, we therefore propose an alternative calibration function to empirically correct this matrix effect on the SIMS measurements of F, S, and Cl.

Ion Beam Analyses of Moisture Reaction for Single Crystal Lithium Deuteride

ABSTRACTIon beam analyses were completed on single crystal LiD (lithium hydride with deuterium on the hydrogen sites) to determine products of hydrolysis with decarbonated H2O (with protium-hydrogen) in an inert gas. Rutherford backscattering spectrometry showed movement of oxygen into the bulk of LiD samples. Hydrolysis rates for the single crystal LiD showed relatively slow initial growth of an oxygen-containing layer. Final growth rates varied widely with H2O level, from 1010 to 1015 (atoms/cm2)/min. at 5.6 and 28 mmol/min. H2O respectively. Simulations of spectra show the hydrolysis product to be LiOH. Elastic recoil detection identifies the hydrogen in the hydroxide layer upon dosing with H2O (with natural, protiated hydrogen) as primarily protium. Micrographs showed island growth occurring initially, with convergence to a full-coverage hydrolysis layer.