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Volume 38, Issue 3
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[in Japanese]1991 Volume 38 Issue 3 Pages 314
Published: April 10, 1991
Released on J-STAGE: May 22, 2009
JOURNAL FREE ACCESSDownload PDF (84K) -
Osami Kamigaito1991 Volume 38 Issue 3 Pages 315-321
Published: April 10, 1991
Released on J-STAGE: May 22, 2009
JOURNAL FREE ACCESSSignificance of the constitutional size in the composites having the constitution of nanometer size (Nano-Composites) was emphasized. Every Nano-Composite should have two critical values, the upper limit and the lower limit, for the dimension of the constitution to posses the distinguishable property as Nano-Composite. The critical values depend on the property expected for the composite. The values were estimated or re-viewed on various basis which are thought to be useful for each property, such as cata-lytic activity, magnetism, optical property as well as mechanical one. For examples: The range of the binding force acting across the surface of solids was estimated from the surface free energy and the ideal strength, which gives the critical value in general expression for the constitutional dimension and also for one basic aspect of catalitic activity. The values are about 7 nm(Si3N4), 4 nm(SiC), 4 nm (Al), 2 nm(Fe), 2 nm(W) and 3 nm(Pt). The value is very small for oxides, 0.5 nm(Al2O3) and 0.4 nm(MgO) probably due to screening effect on the surface. As to magnetic properties, 100 mn for super paramagnetism's occurrence and 20 nm for making the originally hard magnetic material soft one. Optically, the value is about 50 nm for reflective intex change. Mechanically, it is about 100 nm for strengthning or restricting dislocation movement. Some improved properties, which could be expected or have been realized, are described in the relation with the critical values.View full abstractDownload PDF (550K) -
Osamu Inoue, Yasuhiro Sugaya, Ken Hirota, Koichi Kugimiya1991 Volume 38 Issue 3 Pages 322-325
Published: April 10, 1991
Released on J-STAGE: May 22, 2009
JOURNAL FREE ACCESSEffects of oxidation conditions of starting metal powders on the electric properties of "NANOCON" material have been studied. Thin oxide films were formed on the surface of the starting metal powders by heat treatments. The chemical compositions of the thin oxide films were changed by the atmosphere of the oxidation condition; Al-O film was formed at low oxygen patial pressure and Al-Fe-O film was formed at high oxygen partial pressure. These powders were hot-pree-sintered. The electric resistivity of the "NANOCON" material consisted of metal grain with Al-O film was lower than that of the "NANOCON" material consisted of metal grain with Al-Fe-O film. The relationship between the electric resistivity of these "NANOCON" materials and their film composition is discussed.View full abstractDownload PDF (2438K) -
Tohru Sekino, Atsushi Nakahira, Masahiro Nawa, Koichi Niihara1991 Volume 38 Issue 3 Pages 326-330
Published: April 10, 1991
Released on J-STAGE: July 12, 2010
JOURNAL FREE ACCESSMechanical properties and microstructure of Al2O3/W composites have been investigated. These composites were fabricated by hot-pressing the mixture of γ - or α-types of alumina(Al2O3) and fine tungsten(W) powders. In these composites, the fine W particles were located both within Al2O3 matrix grains and at grain boundaries. The fracture strength of Al2O3/5vol%W composites sintered at 1400°C was 700MPa, which is approximately 1.6 times higher than that of the monolithic Al2O3 that prepared under the same conditions. But the strength decreased with increasing sintering temperature. Although the interactions between clacks and W dispersions were partly observed, the fracture toughness was not significantly enhanced. It is supposed that the effects of nano-structure did not sufficiently act on the mechanical properties of the composites because the grain boundary of Al2O3, where large W particles are located, was not strengthened by the dispersions.View full abstractDownload PDF (6614K) -
Dispersion via Electroless Plating ProcedureHidemi Watanabe, Osamu Kimura1991 Volume 38 Issue 3 Pages 331-334
Published: April 10, 1991
Released on J-STAGE: May 22, 2009
JOURNAL FREE ACCESSMetal powder dispersion into ceramics materials is expected to enhance the fracture toughness. For this purpose, a new method is tried to prepare Al2O3 Pd composites. The procedure consists of electroless plating of Pd on Al2O3 powder and the following hot-pressing of the powder. Fracture toughness of hot-pressed composites thus prepared incresed to 4.3MPam1/2, which is about 20 % higher than that of pure Al2O3. SEM observation and EDX analysis on the fractured surface of the composite indicate that fine Pd powders disperse uniformly into Al2O3, matrix.View full abstractDownload PDF (3133K) -
Nobuyuki Hiratsuka, Shigemitsu Fukui, Minoru Fujita, Mitsuo Sugimoto1991 Volume 38 Issue 3 Pages 335-338
Published: April 10, 1991
Released on J-STAGE: December 04, 2009
JOURNAL FREE ACCESSMagnetic properties of iron nitride thin films as well as Fe4N/Fe multilayered films prepared by a reactive plasma deposition method have been investigated. The Fe4N single phase was produced under PN2=4mTorr, substrate temperature=above 300°C and output power of r.f. generator=above 300W.
The multilayered films consisting of Fe/Fe4N/Fe as well as Fe4N/Fe/Fe4N were deposited by control-ling the plasma power. The saturation magnetization of the multilayered films mainly depended on the thickness of the Fe layers. The coercive force of the films was greater than that of the Fe single phase because of nitrogen from the Fe4N layer was diffused into the Fe layer. The film, of a small coercive force of 29 Oe, containing little nitrogen in the Fe layer was made when the deposition rate of the iron in the Fe4N/Fe/Fe4N multilayered film became speeded up.View full abstractDownload PDF (1295K) -
Hiroshi Maiwa, Noboru Ichinose, Kiyoshi Okazaki1991 Volume 38 Issue 3 Pages 339-344
Published: April 10, 1991
Released on J-STAGE: December 04, 2009
JOURNAL FREE ACCESSAl-AIN thin films, AIN-TiN multi-layer thin films and Al-Ti-N thin films were prepared by rf magnetron sputtering. AI-AIN thin films were deposited by reactive sputtering in an atmosphere of mixed gas of argon and nitrogen. The products changed from Al to AIN through Al-AIN phase by increasing partial pressure of nitrogen (PN2). The deposition rate and the electrical resistivity as a function of PN2 were also studied. AIN-TiN multi-layer thin films were prepared by depositing of AIN and TiN alternately. Homogeneous Al-Ti-N solid solution thin films could be prepared by reactive sputtering of multi-metal target on the substrates rotating at 11.25rpm. The structure of the films are classified into three phases: wurtzite type solid solution with x=0-0.13 in Al1-xTixN, unknown phase with x=0.20-0.30, NaCl type solid solution with x=0.40-1.0. The optical transmittance of the solid solution thin films varied with the composition x, suggesting that homogeneous solid solution thin films formed by reactive multi-metal target sputtering.View full abstractDownload PDF (301K) -
Yosihide Watanabe, Yasuhiko Takeda, Tomoyoshi Motohiro, Shoji Noda1991 Volume 38 Issue 3 Pages 345-347
Published: April 10, 1991
Released on J-STAGE: May 22, 2009
JOURNAL FREE ACCESSThin films were formed by simultaneous depositions from two AF-sputter sources which were mounted so that the incident angles of the sputtered particles were +70° and -70° from the substrate normal. A microstructure of ZnTe/SiO2 thin film were examined by TEM. The ZnTe/SiO2 thin film was an anisotropic nm-scale composite whose microstructure was similar to that of the film computer-generated with the simulated deposition conditions. A Cu/SiO2 thin film was also inferred to have an anisotrop ic microstructure through the observation of the polarization of the transmitted light. Simultaneous oblique depositions from two sources will be a promising method to generate unique sans composites.View full abstractDownload PDF (2114K) -
Hiroshi Takada, Atsushi Nakahira, Satoru Ueda, Koichi Niihara, Hiroshi ...1991 Volume 38 Issue 3 Pages 348-351
Published: April 10, 1991
Released on J-STAGE: May 22, 2009
JOURNAL FREE ACCESSThe natural aullite (fabricated from natural kaolin and Al2O3 powders)/SiC nanocomposites were prepared by pressureless reaction-sintering at 1700'C. These composites were composed of mullite with columnartyped grains, fine SiC dispersions and amorphous grain boundary phases. The larger SiC particles (>0.3μm) were dispersed at the grain boundaries, while the finer SiC particles (<0.2 μm) were located not only at the grain boundaries but also within the mullite matrix grains. The microstructure of these composites could be controlled by changing SiC dispersions, heating rate and sintering time. The mechanical properties were strongly improved. The Vickers hardness, fracture toughness and fracture strength were 10 GPa, 2.7 MPam1/2 and 490 MPa, respectively, which are comparable with those of highly pure mullite and their composites. In this paper, special emphasis was placed on the understanding of effects of SiC dispersions and sintering conditions on mechanical properties.View full abstractDownload PDF (3345K) -
Jian-ren Zeng, Isao Tanaka, Yoshinari Miyamoto, Koichi Niihara, Osamu ...1991 Volume 38 Issue 3 Pages 352-356
Published: April 10, 1991
Released on J-STAGE: May 22, 2009
JOURNAL FREE ACCESSThe microstructures and mechanical properties of Si3N4-SiC composites containing 8 to 46 vol% Sic, which were prepared from combustion synthesis and HIP sintering without additives, were studied and compared with those of Si3N4 prepared from conventional methods. Transmission electron microscopic observation revealed the existence of some small SiC particles within the Si3N4 matrix grains. The fracture toughness of the Si3N4-SiC composite was independent of Si, C content, probably because the SiC grains were smaller than the critical size for effective toughening and the formation of elongated Si3N4 grains was not promoted by the Sic dispersions. But SiC additions modified the high-tempera-ture strength of the Si3N4-SiC composites and increased the microhardness at all temperatures.View full abstractDownload PDF (2524K) -
Kansei Izaki, Atsushi Nakahira, Koichi Niihara1991 Volume 38 Issue 3 Pages 357-360
Published: April 10, 1991
Released on J-STAGE: May 22, 2009
JOURNAL FREE ACCESSHot-pressed Si3N4-32%SiC nanocomposite and monolithic Si3N4 for comparision were evaluated for oxidation resistance at 1000-1400°C in static air for 100 hr. The weight gain of Si3N4-SiC nanocomposite was similar to that of Si3N4, except 1000°C. At 1000 and 1200°C oxidation, the surface layer containing cristobalite was formed, and yttrium disilicate was observed after 1400°C oxidation. The nanocomposite did not indicate a degradation in strength and even the strength increase of 20% was observed after 1200°C oxidation, whereas the strength degradation of 20-30%, due to a pit formation, occured for Si3N4.View full abstractDownload PDF (1439K) -
Atsushi Nakahira, Koichi Niihara1991 Volume 38 Issue 3 Pages 361-364
Published: April 10, 1991
Released on J-STAGE: December 04, 2009
JOURNAL FREE ACCESSAl2O3/SiC nanocomposites were successfully prepared by the conventional powder metallurgical technique. The microstructures of Al2O3/SiC nanocomposites were mainly investigated by transmission electron microscopy(TEM). TEM observaions indicated that the Al2O3 matrix grains were essentially equiaxed with the average gain size of 1 to 2 μm and the SiC particles were predominantly dispersed within Al2O3 matrix grains. Al2O3-SiC interfaces in Al2O3 grains containing intragranular SiC were generally observed with faceting but in part with sphere by high resolution electron microscopy(HREM). HREM observations also revealed that the Al2O3 and SiC grains in Al2O3/SiC nanocomposites made direct interfaces without any reacting phases.View full abstractDownload PDF (3119K) -
Ryuichi Matsuki, Hisao Ueda, Takeyoshi Takenouchi, Atsushi Nakahira, K ...1991 Volume 38 Issue 3 Pages 365-368
Published: April 10, 1991
Released on J-STAGE: May 22, 2009
JOURNAL FREE ACCESSHigh density Al2O3/TiC composites were fabricated by a conventional hot-pressing of mixtures of Al2O3 and TiC powders at 1700-1900°C in Ar atmosphere. Transmission electron microscopic observations revealed that TiC particles were dispersed not only at grain boundaries but also within Al2O3 matrix grains. The mechanical properties of these composites were considerably improved by dispersed TiC particles. The fracture toughness of these composites increased from 4MPam1/2 to 6MPam1/2 and the fracture strength also increased from 550MPa to 1100MPa. The effect of TiC dispersions in Al2O3 grains on the mechanicai properties such as strength, toughness and hardness were discussed.View full abstractDownload PDF (3608K) -
Ryoichi Shikata, Yoshinori Urata, Takeshi Shiono, Tomozo Nishikawa1991 Volume 38 Issue 3 Pages 369-373
Published: April 10, 1991
Released on J-STAGE: December 04, 2009
JOURNAL FREE ACCESSZrO2-Al2O3 composites with high fracture strength were developed. The maximum bending strength occured at the addition of 20-40 wt% Al2O3 and reached about 3000MPa. Fracture toughness measured by SEPB method showed the same trend as bending strength and was about 7.5 MPam1/2 at the addition of 20-40 wt% Al2O3. And then, each of large Al2O3 grains was dispersed in the matrix of ZrO2 with small grains.
The addition of Al2O3 reduced the crystal grain size of tetragonal ZrO2 and caused the residual stresses due to the thermal expansion mismatch between ZrO2 and Al2O3. Tensile stress in ZrO2 grains and compressive stress in Al2O3 grains were observed. These residual stresses led to the strengthening of Al2O3 grains and the fracture mode change from inter-granular to trans-granular fracture at ZrO2 grains. From above-mentioned results, it was considered that the enhancement of fracture strength resulted in the increase of fracture toughness, the rise of critical stress to initiate tetragonal to monoclinic ZrO2 transformation and the reduction of flaw size.View full abstractDownload PDF (1454K) -
Katsuaki Suganuma, Genn Sasaki, Teruaki Fujita, Masatoshi Okumura, Aki ...1991 Volume 38 Issue 3 Pages 374-377
Published: April 10, 1991
Released on J-STAGE: December 04, 2009
JOURNAL FREE ACCESSSeveral mechanical properties and the microstructure of the machinable silicon carbide, which is fabricated by sintering β-phase silicon carbide fine powder mixed with polysilastyrene in argon atmosphere, has been evaluated. The bending strength reached 230 MPa at room temperature and there was no degradation in strength up to 1500°C. Such good strength seems to be originated from the tight interconnection among silicon carbide particles formed even at low sintering temperature with the aid of the polysilastyrene forming β-phase silicon carbide. TEM obsevation and X-ray analysis revealed the presence of turbostratic structure ribbon of carbon in nano-scale formed in the pores. The ribbon-like carbon is also one of the productds of polysilastyrene. The machinability of this material is considered to be provided by the presence of carbon, which helps the lubrication in machining, in addition to the porous structure. This material is expected to be high-temperature structural compornents.View full abstractDownload PDF (2845K) -
Hidemi Watanabe, Osamu Kimura, Atushi Nakahira, Koichi Niihara1991 Volume 38 Issue 3 Pages 378-381
Published: April 10, 1991
Released on J-STAGE: May 22, 2009
JOURNAL FREE ACCESSA two layered Al2O3, /SiC composite is prepared. The composite consists of un-reinforced Al2O3, layer and 10 Vol%-SiC whisker reinforced Al2O3, layer, which are simultaneously sintered by hotpressing. Flexural strength of the composite reaches 300MPa and diffrence fracture toughness Kic: are observed for two layers, namely, 5MPam1/2 for reinforced layer and 2MPam1/2 for un-reinforced layer, respectively. Also, thermal stresses resulted in during cooling down to room temperature is discussed.View full abstractDownload PDF (1394K) -
Masaru Yokota, Soichi Yagyu, Kazuhiko Majima, Hiroshi Nagai1991 Volume 38 Issue 3 Pages 382-385
Published: April 10, 1991
Released on J-STAGE: May 22, 2009
JOURNAL FREE ACCESSChemical vapor deposition equipment was applied to produce ultra-fine powders of AlN where Al was melted by radio-frequency generator in NH3 atmosphere.The chemical reaction was carried out at 1450K for 3.6ks.and the obtained samples were analyzed by TEM.SEM and XRD.The degree of AlN synthesis became higher.and the uniformity of ultra-fine AlN perticle size became higher with increasing amount of NH3 gas supply.And the tendency that the amount of AlN particles with sub-micronorder might be higher with increasing flow rate of NH3 gas.was also confirmed.View full abstractDownload PDF (2438K) -
Kazuhiko Majima, Hiroshi Nagai, Norikazu Niimi, Masaru Yokota1991 Volume 38 Issue 3 Pages 386-389
Published: April 10, 1991
Released on J-STAGE: May 22, 2009
JOURNAL FREE ACCESSIn this experiment, vacuum hot pressing (VHP) was applied in order to get the transparent Y2O3. where LiF. NaF or NH4F was added as the sintering additive. Transparent Y2O3 was obtained by LiF addition under following UP conditions: temperature 1573K. pressure 400kgf/cm2, vacuum 10-4Torr. sintering time 2h. In the case of NaF or NH4F, however, the transparent Y2O3 was not obtained, where the residual F(fluorine) was detected by EPMA in the opaque region. Much more homogeneous structure was observed in the transparent Y2O3 than the opaque one, and it was also confirmed that the grain size is larger in the former than the latter.View full abstractDownload PDF (1781K) -
Jing-Feng Li, Akira Kawasaki, Ryuzo Watanabe1991 Volume 38 Issue 3 Pages 390-394
Published: April 10, 1991
Released on J-STAGE: May 22, 2009
JOURNAL FREE ACCESSIn an attempt to strengthen and toughen silicon carbide ceramics, fully dense SiC-AlN alloys containing up to 25mol%AIN were fabricated by hot-isostatic pressing of the reaction-synthesized SiC-AlN solid solution powders. It was found that the solution of AlN yields much higher strength (up to 1000MPa at 5mol%AlN), and increases fracture toughness of SiC. In the SiC-AlN composites prepared by hot-isostatic pressing of the SiC and AlN elememtal powder mixtures, the addition of AlN particales improves fracture toughness more effectively in comparison with the single phase alloys.View full abstractDownload PDF (1385K) -
Tsuyoshi Takenaka, Kozi Nishio, Junzo Fujioka, Shun-ichi Minakata1991 Volume 38 Issue 3 Pages 395-396
Published: April 10, 1991
Released on J-STAGE: December 04, 2009
JOURNAL FREE ACCESSCarbon matrix of C/C composites were modified for the relaxation of thermal stresses between C/C composites and ceramic coatings. Porous C/C composites with various amounts of carbon matrix and porosity were prepared. Liquid silicon was impregnated into porous C/C composites and reacted chemically with carbon matrix to form silicon carbide. Thermal expansion of C/C composites could be controlled between 1.7 to 3.5×10-6/°C by altering the amount of silicon carbide in the matrix.View full abstractDownload PDF (1166K) -
[in Japanese]1991 Volume 38 Issue 3 Pages 398
Published: April 10, 1991
Released on J-STAGE: May 22, 2009
JOURNAL FREE ACCESSDownload PDF (92K) -
Shigeru Hayakawa1991 Volume 38 Issue 3 Pages 399-402
Published: April 10, 1991
Released on J-STAGE: July 12, 2010
JOURNAL FREE ACCESSTechnology and society develop interdependently. In accordauce with the diversification of societal needs, technological needs have also diversified. Successor to industrial society will be advanced industrial society. Technological foundation to support such society will be materials technology. This paper describes the recent trends in materials research and also outlines ion engineering technology which typifies the recent trends. A new viewpoint for materials research is proposed in relation to the ion engineering technology.View full abstractDownload PDF (202K) -
Miyuki Hagiwara1991 Volume 38 Issue 3 Pages 403-406
Published: April 10, 1991
Released on J-STAGE: May 22, 2009
JOURNAL FREE ACCESSThe Takasaki Radiation Chemistry Research Estabishment of Japan Atomic Energy Research Institute started the construction of the ion beam irradiation facilities to promote a new project "Advanced Radiation Technology Study using Ion Beams (ART project)". The ART project is intended to push forwarded with R&D on materials for space and nuclear fusion reactors, biotechnology and new functional materials using ion beams. Two ion accelerators (AVF cyclotron and Tandem type accelerator) are now under construction to be operational before the end of 1991, and other two accelerators (van de Graaff accelerator and ion beam implanter) are further scheduled to be installed in 1993. Some noticeable results were obtained in the preliminary studies so far. SiC which expected as semiconductor materials for space use was found to be more radiation resistant than Si. A new radiation resisant fiber reinforced plastics was developed. It retains good mechanical properties at low temperature even after the irradiation of electrons up to a dose of 100 MGy. Studies were also conducted to see the effects of ion beam irradiation on bacteria and organic thin films.
The polymerization of diyne acids by heavy ion beams was found to take place along with the improvement of molecular orientation in the film.View full abstractDownload PDF (267K) -
Yukinori Saito, Hajime Horie, Shinji Suganomata1991 Volume 38 Issue 3 Pages 407-410
Published: April 10, 1991
Released on J-STAGE: May 22, 2009
JOURNAL FREE ACCESSCo ions were implanted into colorless and transparent synthetic sapphires with doses of 5X1016-5X1017 ions/cm2 at an energy of 20 keV. Optical transparencies in the visible region (400-700nm) and XPS (X-ray photoelectron spectroscopy) spectrum were measured for as-implanted samples and annealed ones up to 1200°C in sequence. Although an as-implanted sample showed only dark grey, on heating the sample its color tone was gradually changed. The color turned green when it was heated at 800°C for 3 h and showed large absorption in the range of wavelength shoter than about 530 nm and a small dip in the range of 600-660 nm. Light blue color was obtained by heating the sample at 1000°C for 3 h and showed a broad absorption peak centered at about 610 nm.
XPS spectra of Co2p3/2 implanted into sapphire was changed when it was heated at 800 or 1000°C. Although the spectra for the as-implanted sample almost coincided with that of metal, the spectrum for the annealed ones showed two peaks, one near the metallic state and the other apart by about 3 eV in the binding energy, which indicates the existence of two types of electronic configurations of Co with different binding energies in the colored sapphire.View full abstractDownload PDF (273K) -
Masami Ikeyama, Kazuo Saitoh, Hiroaki Niwa, Yoshiko Miyagawa, Souji Mi ...1991 Volume 38 Issue 3 Pages 411-414
Published: April 10, 1991
Released on J-STAGE: December 04, 2009
JOURNAL FREE ACCESSSurface swelling of sintered silicon-nitride, sintered alumina and single crystal sapphire implanted with 0.7-3 MeV N+. Si+ and Ni+ ions to 5×1013-5×1017 ions/cm2, were evaluated by measuring the step height of the implanted region with a surface profile meter. The swelling became measurable when the dose exceeded 1×1014-1×1015 ions/cm2, increased with increasing dose, then saturated. In the case of implantation of heavier ions or for low temperature implantation, the dose required to induce a measurable swelling is lower and the step height for saturation is higher. The step height profile versus dose for silicon-nitride is not similar to the one for alumina or sapphire. The swelling of the single crystal is larger than that of the sintered material, generally. After the annealing (1200°C, 1 hr in vacuum), the swelling is reduced about 30%. This phenomenon of surface swelling can be simulated semi-qualitatively by Monte Carlo calculation.View full abstractDownload PDF (282K) -
Susumu Sato, Hiroshi Watanabe, Katsuo Takahashi, Masaya Iwaki1991 Volume 38 Issue 3 Pages 415-418
Published: April 10, 1991
Released on J-STAGE: May 22, 2009
JOURNAL FREE ACCESSA study has been made of the dependency of electrical conductivity and structure of implanted carbon-films, on the target temperature during ion implantation. The c-film was produced by an ion-beam sputtering method on quartz substrates. Implantation of C+-ions was performed at 150 keV, held at the separate temperatures of -100 and 200°C, with doses of 2x1016 ions/cm2. The sheet resistivity was measured by a four point probe method at room temperature. Sheet resistivity was found to vary, depending on the target temperature during ion implantation, by approximately three orders of magnitude. Raman spectra were obtained and analyzed. The modified Raman spectra contained four broad peaks. The peak at 1150, 1360 and 1585 cm-1 is assigned to hydrogenous carbon, disordered graphite and graphite, respectively, and that detected at approximately 1500cm-1 is proposed owing to amorphous carbon. The peak at 1500cm-1 showed large differences in intensity at target temperatures between -100 and 200°C. These results are similar to those reported for ion implanted diamond.View full abstractDownload PDF (290K) -
Isao Sakamoto, Nobuyuki Hayashi1991 Volume 38 Issue 3 Pages 419-422
Published: April 10, 1991
Released on J-STAGE: December 04, 2009
JOURNAL FREE ACCESSAustenitic stainless steel has been irradiated with metallic-ions and gas ions in order to perform a surface modification of stainless steel. An irradiation effect in stainless steel has been investigated by means of GXRD and CEMS, which show good surface-sensitivity. Metallic-ion irradiation in 17/7 stainless steel has induced the martensitic α phase, especially in the irradiation of Fe ions. Furthermore, a few kinds of gas ions has been used to induce the α phase in 304 stainless steel. It has been shown by GXRD and CEMS that Xe ion irradiation is most effective to induce the α phase in 304 stainless steel. In the case of rare-gas ion irradiation, the degree of the phase transformation has increased with increasing mass of ion species. On the other hand, the formation of the a phase has not occured in stainless steel after N2 ion irradiation. Therefore, we conclude that Fe ion and Xe ion irradiation are suitable to perform a surface modification in stainless steel.View full abstractDownload PDF (272K) -
Susumu Tamura, Masato Matubara, Tosio Nakazima, Katsuhiro Yokota, Saic ...1991 Volume 38 Issue 3 Pages 423-426
Published: April 10, 1991
Released on J-STAGE: December 04, 2009
JOURNAL FREE ACCESSZnSe films were grown on GaAs substrates using partially ionized Zn and Se beams, without heat treatment before growth. The ionization of Zn and Se beams was effective to remove the surface contamination. The quality of ZnSe films strongly depended on substrate bias. High-quality ZnSe films with smooth surfaces epitaxially grew on the substrate biased to -40V.View full abstractDownload PDF (3642K) -
Tatsuo Fujii, Mikio Takano, Yoshichika Bando, Takashi Okuda1991 Volume 38 Issue 3 Pages 427-430
Published: April 10, 1991
Released on J-STAGE: May 22, 2009
JOURNAL FREE ACCESSVery recently, an artificial new material "bismuth iron garnet" was prepared for the first time with a reactive ion-beam-sputterring method. A magnetic characterization of this single crystalline garnet film was achieved by applying conversion electron Mössbauer spectroscopy (CEMS). To examine the temperature dependence of sublattice magnetization, CEMS measurments were made at 6, 78, 290, and 670 K, i.e. in both the ferrimagnetic and paramagnetic regions. The magnetic and quadrupole hyperfine interactions as compared with YIG indicated continuous effects of lattice expansion owing to the large spherical size of Bi3+ ions. The temperature dependence of sublattice magnetization has been explained by the two-sublattice molecular field model with a molecular field constant Nad slightly modified from that of YIG.View full abstractDownload PDF (253K) -
Kohei Okumura, Yoshihiko Itoh, Shogo Hibi, Akio Itoh, Tatsumi Hioki1991 Volume 38 Issue 3 Pages 431-434
Published: April 10, 1991
Released on J-STAGE: May 22, 2009
JOURNAL FREE ACCESSBy combining vapor deposition of organic compounds and simultaneous energetic Ar+ion irradiation, carbonaceous films were deposited onto substrates of a bearing steel (SUJ2). The organic compounds were benzene, pentaphenylether, poly-(dimethylsiloxane) and pentaphenyl-trimethyl-trisiloxane.
All the carbonaceous films produced were amorphous and showed low coefficient of friction less than 0.2 in ambient atmosphere. In particular, the films produced from the siloxane compounds (ion-irradiated silicone films) showed extremely low coefficient of friction less than 0.05. Furthermore, the friction coefficient of the ion-irradiated silicone films was much less sensitive to moisture compared to diamond-like carbon films prepared by plasma-enhanced chemical vapor deposition.
Scanning electron microscopy and electron-probe micro-analysis for the pins of SUJ2 revealed that the ion-irradiated silicone films are easily transferred to the surface of the pin during sliding. This fact may be related with the very low friction coefficient for the ion-irradiated silicone films.View full abstractDownload PDF (1830K) -
Hidenori Kohzuki, Kazutoshi Yamada, Kenji Yamagishi, Yosuo Okuno1991 Volume 38 Issue 3 Pages 435-439
Published: April 10, 1991
Released on J-STAGE: May 22, 2009
JOURNAL FREE ACCESSAn investigation was carried out to synthesize cBN film on a Si wafer by means of a reactive ion plating process assisted hot cathode plasma discharged within a parallel magnetic field. The BN films prepared under various depositing conditions were analyzed by IR spectroscopy and microprobe chemical state analysis. It was found that the deposited BN films were composed of cBN and hBN, and the cBN content in the film ranged from 0% to a maximum of 82%. The cBN content was dependent on the ionization electrode current, RF power applied to a substrate and EB power(evaporation rate of Boron), and increased with increasing values of their parameters. But the BN film could not be deposited under excessive RF power because of sputtering predominantly caused by ions impinging on a substrate.
The cBN content was increased remarkably by introducing Ar gas with N2 gas into the evaporation chamber. Therefore, it was assumed that thermal spikes caused by Ar ions impinging on the growing BN film play a significant role for the formation o f cBN film.View full abstractDownload PDF (276K) -
Akio Okamoto, Soichi Ogawa, Yoshihiko Suzuki, Katsumi Takiguchi1991 Volume 38 Issue 3 Pages 440-443
Published: April 10, 1991
Released on J-STAGE: May 22, 2009
JOURNAL FREE ACCESSIon assisted deposition is very useful method for obtaining the films with desired properties. The role of ions in this method is to give kinetic energy and chemical activity to a substrate or a growing film. Using a reactive gas ion, it is able to react on the deposition atoms. Consequently various compounds are formed. Control of the incident ion energy, curret and/or the ion species makes to be possible to regulate the film properties such as density, crystal structure, electrical resistivity and so on. We have ever developed a new type of ion source with low energy and high current density. It was discussed that the effects of ion kinetic energy and ion current on the crystal structure of Cu-O thin films prepared by oxygen ion assisted deposition using the ion source developed by us.
The crystal structure of Cu-O films were prepared in various ion energy and current was studied by X-ray diffraction measurement. The following results were obtained:
(1) The X-ray diffraction peaks due to Cu2O crystal structure are appeared, in spite of low current bombardment of oxygen ion (ion current : O.1mA).
(2) As ion current is increased from 0.1mA to 1.2mA and from 1.2mA to 4.4mA at adequate acceleration voltage, the crystal structure of the prepared films is changed as follows, Cu-Cu2O system --> Cu2O system --> CuO system.View full abstractDownload PDF (207K) -
Yoshimasa Kumashiro, Eiji Kamijo1991 Volume 38 Issue 3 Pages 444-446
Published: April 10, 1991
Released on J-STAGE: December 04, 2009
JOURNAL FREE ACCESSTiO2 thin films were prepared on glass substrates by reactive ion beam sputtering method. A metalic Ti target was sputtered by Ar ion beam, and O2 gas was introduced as reactive gas.
Deposition rate of films increased as ion beam energy became higher. When oxygen partial pressure was 5×10-5Torr or above it, Ti atoms reacted with oxygen, and transparent TiO2 films were obtained. Films deposited on glass substrates at 200°C or above it had crystal structure of the rutile which is the high-temperature stable phase of TiO2. These results suggest the contribution of energy of sputtered particles to decrease of crystallization temperature.View full abstractDownload PDF (158K) -
Eiji Kamijo1991 Volume 38 Issue 3 Pages 447-449
Published: April 10, 1991
Released on J-STAGE: December 04, 2009
JOURNAL FREE ACCESSTiN and complex TiN films doped with small amounts of Al and V were prepared on a glass substrate by the reactive ion beam sputtering method using Ti and Ti-6Al-4V alloy target. The chemical bonding, chemical composition, crystal structure and microstructure were investigated using XPS, XRD and TEM. The results of XPS analysis indicate a clear peak due to chemical bonding of Ti-N, AI-N and V-N respectively. The Ti/N ratio depends much more on the nitrogen partial pressure than on substrate temperature, and the nitrogen partial pressure in excess of 5×10-5 Torr is necessary to prepare films with Ti/N=1. It suggest the effect of sputtered Particles's energy that crystalline TiN films were obtained on conditions of substrate temperature 25 °C and nitrogen partial pressure 5×10-5 Torr. The results of TEM analysis clearly indicate that crystal growth in TIN is inhibited by doping with small amounts of Al and V.View full abstractDownload PDF (1289K)
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