The selenization of metallic precursors is a widely used and investigated technique for the fabrication of Cu(In,Ga)Se2 films on large areas. A vacuum process with Se supply from the gas phase can be a suitable way to achieve a homogeneous, fast and controllable selenization reaction. In this study in situ XRD measurements are employed to investigate the reaction path for this type of process. The experimental setup is based on a reaction box mounted at a white light beamline of the synchrotron facility BESSY. Diffraction signals as well as Kα fluorescence lines of Mo, In and Se can be measured with high time resolution via energy dispersive detection. To elucidate the influence of selenium on the metallic precursors upon heating a comparison of experiments with and without Se exposure is presented. For the Se-free process the phases In and a Cux(In,Ga)y-phase are detected at room temperature. The solid In phase melts according to its melting point at approximately 150°C, the remaining metallic phase melts at significantly higher temperatures of approximately 600°C. In the selenization process the metallic phases behave similar to the Se-free annealing process. The first detectable Se-containing phases are indium selenides. The indium selenides and the metallic diffraction signals vanish when chalcopyrite is formed. The Se fluorescence intensity was utilized to evaluate Se incorporation in the layers. Solar cells made out of absorbers from this kind of process exhibit fill factors of up to 72% and efficiencies up to 14%. The open circuit voltage was comparatively low with 535 mV and QE measurements confirmed a low band gap of approximately 1.0 eV. Energy-dispersive X-ray spectroscopy (EDS) measurements on the cross section showed a significant Ga enrichment at the back of the film.

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X-ray diffraction (XRD), Mössbauer spectrometry (MS), secondary ions mass spectroscopy (SIMS) and laser-ablation microprobe-inductively coupled plasma-mass spectrometry (LAM-ICP-MS) were used to study mineral samples of Colombian auriferous ores collected from the "El Diamante" mine, located in the municipality of Guachavez-Nariño, in Colombia. The samples were prepared as polished thin sections and polished sections. From XRD data, quartz, sphalerite and pyrite were detected and their respective cell parameters were estimated. From MS analyses, pyrite, arsenopyrite and chalcopyrite were identified; their respective hyperfine parameters and respective texture were deduced. Multiple regions of approximately 200 × 200 μm in each sample were analyzed with SIMS; the occurrence of "invisible gold" associated mainly with pyrite and secondarily with arsenopyrite could thus be assigned. It was also found that pyrite is of the arsenious type. Spots from 30 to 40 μm in diameter were analyzed with LAM-ICP-MS for pyrite, arsenopyrite and sphalerite; Au is "homogeneously" distributed inside the structure of the arsenious pyrite and the arsenopyrite (not as inclusions); the chemical composition indicates similarities of this "invisible gold", forming a solid solution with arsenious pyrite and arsenopyrite. One hundred nineteen and 62 ppm of 'invisible gold' was quantified in 21 spots analyzed on pyrite and in 14 spots on arsenopyrite, respectively.

In this work, the structural, magnetic and mechanical properties of Nd16Fe76−xCoxB8 alloys with a varying Co content of x = 0, 10, 20 and 25 were experimentally investigated by X-ray diffraction (XRD), Mössbauer spectrometry (MS) and vibrating sample magnetometry (VSM) at room temperature (RT), and microhardness tests were performed. The system presented hard Nd2Fe14B and the Nd1.1Fe4B4 phases for samples with x = 0; when the concentration increased to x = 20 and 25, the CoO phase appeared. All MS data showed ferromagnetic behavior (eight sextets: sites 16k1, 16k2, 8j1, 8j2, 4c, 4e, sb) associated with the hard and soft magnetic phases, and one paramagnetic component (doublet: site d) associated with the minority Nd1.1Fe4B4 phase, which was not identified by XRD. All samples were magnetically hard and presented hard magnetic behavior. The increase of Co content in these samples did not improve the hard magnetic properties but increased the critical temperature of the system and decreased the crystallite size of the hard phase. There was a general tendency towards increased microhardness with cobalt content that was attributable to cobalt doping, which reduces the lattice parameters and porosities within the sample, improving its hardness.

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