Crystal growth modified by pulsed laser irradiation on growing surface in Ba-Cu-O film preparation by laser ablation

Ba2YCu3Ox superconducting films were prepared by Nd:YAG laser ablation, equipped with a second (ArF excimer) laser for irradiation onto the growing film surface. The irradiation onto the film during the deposition were delayed for various delay times against the ablation of Ba2YCu3Ox target. The experiment showed that the second laser irradiation within several tens ps around the ablation event induces a change of the crystal orientation. This result suggests that the crystal growth for the laser ablation is determined mainly around this time scale

Novel oxidation process of hydrogenated amorphous silicon utilizing nitrous oxide plasma

金沢大学理工研究域電子情報通信学系A novel oxidation process in hydrogenated amorphous silicon (a-Si:H) using nitrous oxide (N2O) plasma was studied in detail for the first time. The N2O-plasma oxidized a-Si:H has an excellent interface whose interfacial defect density is largely reduced compared with the O 2-plasma oxidized a-Si:H. It was elucidated that this oxide layer has almost stoichiometric composition and contains a small amount of N piling up at the interface between the oxide layer and a-Si:H layer. It also turned out that this process has less ion damage than the O2-plasma oxidation process. The reason for the reduction of the interfacial defect density is attributed to the presence of N at the interface and/or less ion damage in this process

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Amorphous Thermal Spray Coating with Hard Materials Exhibiting Cleavage Fracture

Hard materials were mixed with alloy powders and thermally sprayed at an ultra rapid cooling rate of more than 106°C/s. For example, 65Ni15Cr16P4B at% alloy powder containing tungsten carbide was thermally sprayed. SEM image showed tungsten carbide paticles were scattered in the amorphous alloy coatings. The resulting thermal coatings showed low friction and high wear resistance in a reciprocating-slide-type friction-testing machine because tungsten carbides exhibited cleavage fracture. The stress analysis of an amorphous alloy coating with low friction was also carried out by the finite element method

LPE-Like Crystal Growth of YIG Ferrimagnetic Thin Films by Pulsed Laser Ablation with Molten Droplets

金沢大学工学部Yttrium iron garnet (YIG) films were grown by pulsed laser ablation (PLA) on (111) Gadolinium Gallium Garnet (GGG) substrates. The second harmonic of YAG laser (532 nm) with a high laser fluence was employed to produce YIG droplets efficiently. It was found that YIG films prepared at RT substrates have a large number of solidified droplets of various sizes. Highly oriented YIG crystals were grown on the (111) GGG substrate heated at 860°C by PLA using a large number of molten droplets, suggesting an LPE-like growth. This YIG film shows a small ferrimagnetic resonance linewidth of 7.5 Oe. This value is quite small for films prepared by vapor-phase epitaxy techniques. © Springer-Verlag 1999