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Inoue, Aichi; Yamamoto, Shunya; Nagata, Shinji*; Yoshikawa, Masahito; Shikama, Tatsuo*
Nuclear Instruments and Methods in Physics Research B, 267(8-9), p.1480 - 1483, 2009/03
Times Cited Count：12 Percentile：62.36(Instruments & Instrumentation)We quantitatively studied the relation between hydrogen retention and optical properties induced by hydrogen ion implantation in tungsten trioxide (WO
) films. Films of WO (300 nm) covered with tungsten metal layers (200 nm) were prepared on transparent SiO
substrates by a reactive sputtering in Ar and O mixture. When H
ions were implanted into the samples at an acceleration voltage of 10 kV, the concentration of hydrogen retaining in the WO films increased up to 0.4 H/W in proportion to the fluence of H ions. The optical absorption coefficient at 750 nm of samples increased linearly by 3 
m
with increasing the concentration of hydrogen implanted up to 0.1 H/W. And then, increased and saturated at 4 m with the increase of hydrogen concentration higher than 0.1 H/W. It was found that the hydrogen retention up to 0.1 H/W in tungsten trioxide layers can be monitored by measuring the optical absorbance.
Nagata, Shinji*; Sasase, Masato*; Takahiro, Katsumi*; Tsuchiya, Bun*; Inoue, Aichi; Yamamoto, Shunya; Shikama, Tatsuo*
Nuclear Instruments and Methods in Physics Research B, 267(8-9), p.1514 - 1517, 2009/03
Times Cited Count：9 Percentile：53.48(Instruments & Instrumentation)In this study, effects of the ion implantation on the phase transformation and nano-crystalline formation were examined in Zr-based metallic glasses. Samples were 2 mm thick plates and thin films of Zr
Al
Ni
Cu
prepared by casting in a copper mold and by using RF magnetron sputtering, respectively. Ions of Mg, P, Au and Bi with 100-500 keV were implanted in the samples up to 2 
10
ions/cm
at room temperature. Nano-crystalline structure was found in implanted samples by TEM observation, while the long-range order in the structure was not found for the X-ray diffraction patterns. The electron diffraction patterns indicated the formation of fcc-ZrCu in the P, Au, and Bi implanted region. Changes of the binding energy of the core level electron and valence band structure suggested the formation of Au-Zr or Au-Cu alloys in the Au ion implanted region.
-FeSi thin films and Si or silicon-on-insulator substratesSasase, Masato*; Zhuravlev, A.*; Shimura, Kenichiro*; Yamaguchi, Kenji; Yamamoto, Hiroyuki; Shamoto, Shinichi; Terai, Takayuki*; Hojo, Kiichi
no journal, ,
The effect of the substrate/film interface structure and compositional changes at the interface has been investigated by using two different substrates (Si(100), silicon-on-insulator (SOI)) with cross sectional transmission electron microscope (TEM). The observed images show that the -FeSi on Si(100) were aggregated through the subsequent annealing, forming -FeSi particles with the size of 20
200 nm. In the SOI sample, expansion of the buried SiO layer was significantly seen from TEM images and EDS mapping through the subsequent annealing. Aggregation also occurred to form 2030 nm -FeSi particles with SOI substrate. No -FeSi/Si interface is observed since the SiO layer swelled and top surface Si layer disappeared through the annealing. On the other hand, the -FeSi/Si interface is still observed even after the subsequent annealing when Si(100) substrate was employed.
Yamamoto, Shunya; Inoue, Aichi; Nagata, Shinji*; Sugimoto, Masaki; Yoshikawa, Masahito
no journal, ,
Tungsten trioxide (WO) films are known to show optical absorbance changes due to the formation of tungsten bronze with hydrogen incorporation (gasochromism), and it can be used for hydrogen sensors. We report the effect of ion irradiation on the gasochromism of WO films with various crystalline structures such as amorphous, polycrystalline and single crystal. Ion irradiations with 350 keV helium and oxygen were performed. Amorphous WO films showed good gasochromic coloration. On the other hand, polycrystalline and single crystal WO films show poor gasochromic coloration. After amorphized polycrystalline WO films by the ion irradiations, the improvement of gasochromic coloration was observed. The results suggest that the gasochromism of WO films is influenced by the change of crystalline structure by ion irradiation.
