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Nanocomposite thin films consisting of Au nanoparticles embedded in yttria-stabilized zirconia (YSZ) were synthesized at room temperature by radio frequency magnetron co-sputtering from YSZ and Au targets and subsequently annealed in an argon atmosphere. Au microstructure and particle size were characterized as a function of annealing temperature from 600 to 1000 °C by x-ray diffraction, transmission electron microscopy, scanning electron microscopy, and Rutherford backscattering spectroscopy. Spectroscopic ellipsometry was also used to determine the optical constants of the resulting films. In particular, the refractive index of the nanocomposites was found to undergo an anomalous dispersion in the spectral region where the extinction coefficient achieves its maximum. Additionally, the incorporation of Au in the YSZ matrix was found to increase the refractive index in comparison to that of YSZ. At annealing temperatures higher than 800 °C, a good agreement was found between experimental findings and theoretical models using bulk dielectric functions for Au, as modified to account for a reduced mean free path for scattering than that for free electrons. However, for annealing temperatures below 800 °C, an additional offset was required for the optical constants of Au to obtain good agreement between theory and experiment. This behavior was attributed to a relatively high atomic Au concentration in the YSZ matrix.

Selective-area laser deposition and selective-area laser-deposition vapor infiltration are two gas-phase solid-freeform techniques capable of the direct fabrication of arbitrary structures. The wide range of available gas precursors allows unique combinations of materials to be achieved in the final shape. Tailoring of the local microstructure can be achieved by carefully controlling processing temperature, gas partial pressure, and other variables. The versatility of the two techniques can be seen in the fabrication of a structure comprising multiple materials.

Among many advantages of the solid freeform fabrication (SFF) technology is the possibility of building geometrically complex macrocomponents and embedding microdevices in situ within such components during the fabrication process. One of the promising approaches to this goal is to combine two SFF methods, selective area laser deposition (SALD) and the closely related selective area laser deposition vapor infiltration (SALDVI), [1][2][3][4][5] with the former to make the Fig. 6-Variation of normalized work-hardening rate (10 3 /E ) with embedded devices in situ and the latter to fabricate the temperature.macrocomponents. The SALD uses a scanning laser beam to produce a solid material by locally decomposing gas precursors, while SALDVI is a combination of layered pow-Thus, it is obvious in the present investigation, from the der distribution and vapor infiltration of the layered powder observations of serrations in the load extension curves, plawith SALD. [5] Because SALD and SALDVI are completely teaus in the flow stress vs temperature curves, negative compatible gas phase approaches, an electromechanical strain-rate sensitivity, and minimum in ductility and maxicomponent containing embedded microdevices can in princimum in the rate of work-hardening vs temperature curves ple be fabricated in a single integrated SALD/SALDVI prothat the alloy 834 exhibits a pronounced tendency for DSA cess. In this work, the feasibility of combining these two in the temperature range 573 to 823 K.gas phase SFF approaches in order to fabricate an in situ thermocouple, embedded in an arbitrarily shaped component, has been investigated.

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