[en] This study examines the sintering of inkjet printed nanoparticle copper ink in a room environment using a laser as a high speed sintering method. Printed patterns were sintered with increasing laser scanning speed up to 400 mm s"−"1. The resistivities of the sintered structures were measured and plotted against the scanning speeds. Increased resistivity seems to correlate with increased scanning speed. A selections of analytical methods was used to study the differences in microstructure and composition of the sintered structures. Based on the results, no discernable difference in the microstructure was noticed between the structures sintered using 20 mm s"−"1 to 400 mm s"−"1 scanning speeds; only the structure scanned using 5 mm s"−"1 speed showed a vastly different microstructure and no resistivity was measurable on this structure. Compositional studies revealed that, apart from the structure scanned with 5 mm s"−"1 speed which contained the highest oxygen, the rest of the structures showed a steady oxygen increase with increased scanning speed. (paper)

[en] Er³⁺ doped phosphate glasses with the composition 75NaPO_3-25CaF₂ (mol%) were prepared at different melting temperatures to demonstrate the importance to quantify the fluorine content when preparing oxyfluoride glasses. Indeed, increasing the melting temperature from 900 to 1000 °C leads to a small reduction in the fluorine content from 9.4 at % to 8.8 at % as quantified using EPMA. Whereas this loss of fluorine can be suspected from small changes in the thermal properties of the glass, it increases significantly the glass crystallization tendency in this glass system. This means that a heat treatment of the as-prepared glass should be performed when evaporation of fluorine during the glass melting is suspected. Sample preparation for the characterization of the spectroscopic properties of the glasses is discussed here as well; bulk glasses should be used when measuring the spectroscopic properties of oxyfluoride glasses, which are known to be hygroscopic. It is shown, in this work, that a heat treatment of the glass within the investigated glass system leads to transparent glass-ceramics with volume precipitation of Er³⁺ doped CaF₂ crystals with strong upconversion.

[en] Persistent luminescence (PeL) was obtained from glasses with the composition (75NaPO₃-25CaF₂) (in mol%) by adding PeL microparticles SrAl₂O₄:Eu²⁺,Dy³⁺ in the melts using the direct doping method. The glasses exhibit a strong PeL although they crystallize upon quenching. The crystallization was related to the poor thermal stability of the glass, and also to the extensive loss of fluorine during the glass preparation. The use of quartz crucibles and the long process time used to prepare glasses using the direct doping method are responsible for the fluorine losses.