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Cobalt nanoparticles were produced by employing the liquid-phase reduction method and hydrazine. The effect of citric acid additives on the formation and growth mechanism of cobalt nanoparticles was investigated using polarization methods. The cobalt nanoparticles produced in 0.2 M cobalt sulfate and 5 M hydrazine at 298 K had a spherical shape with a diameter of 400 nm. The dendritic nanoparticles formed with the decreasing of hydrazine concentration at 298 K. On the other hand, dendritic large particles are confirmed at 353 K. It was confirmed that the reduction reaction progressed with the addition of citric acid, and a hexagonal close-packed (εCo) phase was formed.

Cooling performance of Yb : glass was improved with an index-matching liquid. 1-bromonaphthalene was used in the interfacial gap of hybrid gain material between Yb : glass and sapphire blocks. Thermal lens effects under an intensity of 20 kW cm−2 were effectively reduced. The improved hybrid gain material Yb : glass and sapphire can increase repetition rates of laser systems.

Summary form only given. We present a parametric generator based on the novel nonlinear material periodically poled stoichiometric LiTaO/sub 3/ (PPSLT) and a recently developed high-power femtosecond Yb:KY(WO/sub 4/)/sub 2/ (Yb:KYW) thin-disk laser. We achieved simple and robust single-pass OPG at the full repetition rate of 24 MHz. We obtained stable 1 W signal power in 320 fs-pulses with a good transverse beam quality (M/sup 2/ = 1.1) at 1.45 /spl mu/m and 0.6 W of idler power at 3.55 /spl mu/m for 7.8 W pump power. For a few minutes, even 2.5 W of signal output power have been achieved. The damage resistance of PPSLT seems to be significantly better than for congruent PPLN.

The effects of absorbed water of spin-on glass (SOG) and tetraethylorthosilicate (TEOS)-O/sub 3/ NSG on MOS transistor hot carrier degradation were investigated. It was found that the absorbed water in SOG and TEOS-O/sub 3/ NSG film desorbs from the film during subsequent low temperature annealing and causes hot carrier degradation. It was also found that plasma CVD silicon oxide (P-SiO) deposited under certain conditions suppresses the hot carrier degradation drastically. Because the P-SiO film has a small water absorption rate, it blocks water penetration to the silicon surface. >

Laser processing on a silicon plate was observed. A free running flashlamp pumped Ti:sapphire laser was used. A pair of PIN detectors was useful for the detection of penetration. The photographs of keyhole were taken by laser microscopy.

Previously, we reported a silicon torsional resonant mirror driven by a PZT plate through link beam leverage effects and confirmed the device operation. Our device is mechanically reliable and stable since there are no metal leads on the vibrating silicon torsional beams and the mirror is supported by 6 beams. We present an improved device having much higher performance through both design and process optimization based on detailed FEM simulations and refinement of the fabrication process.

Oxygen precipitation in CZ silicon crystal depends on the existence of an ambryo. During crystal growth embryos are assumed to form at carbon atoms. We simulated the embryo formation based upon a thermally-activated heterogeneous nucleation model. Results for the case of an isothermal pre-anneal agree with experiment for homogenized wafers with various carbon content. Results for the cooling process during crystal growth indicate that the thermal history during tailing and slow cooling determine embryo formation in a large part of a silicon crystal with a larger diameter and reduced carbon content.

The two‐step thermal anneal has been investigated in detail for the control of oxygen precipitation. The correlations of interstitial oxygen reduction after the two‐step thermal anneal, the interstitial oxygen in the as‐grown wafer, and the microdefect density are made clear. There is a critical oxygen concentration for the oxygen precipitation. It depends on the first step annealing time and the substitutional carbon concentration. The two‐step thermal anneal was applied successfully to a CCD image sensor and CMOS LSI to improve their performance.

Phenoxymethyllithium, which was prepared from t ributyl (phenoxymethyl) tin by tinlithiumexchange reaction, reacted with various electrophiles to give alkylation and/or condensation products in good yields.

Oxygen concentration in as-grown silicon crystals was controlled by doping oxygen intentionally. Oxygen concentration depended linearly on the surface area of fused quartz pieces placed at the bottom of Si3N4 crucible which is made by CVD using SiCl4+NH3→Si3N4 reaction.

The effect of welding on the local buckling of aluminium thin-walled sections is focused in this paper. With regard to a round-house type law material and by considering different hardening parameters as well as plate slenderness, the effect of welding in terms of geometrical imperfections, residual stresses and heat affected zones are analysed by means of a finite element analysis. The obtained results emphasise the influence of welding on the strength of slender plates, which has been only partially evidenced by experimental analyses. Besides, the comparison with the new EC9 approach allows to check the reliability of the design curves with respect to such a phenomenon.