ISSN:1042-0150    

DOI:10.1080/10420159208219821

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

A new field of research—Quantum Beam Engineering–a systemized technology of the many types of quantum beam is proposed as an advanced research area in nuclear engineering, to promote wider scientific research and more extensive industrial applications. Here, quantum beam means the nuclear radiation, accelerated particle beam and the many secondary particles that are their reaction products. These are photons (Laser, Synchrotron radiation, X-ray and gamma-ray), charged particles (electron, proton and heavy ions) and other particles (neutron, positron, muon etc.). Presented here is an introductory review on the current progress of quantum beam engineering, which has been discussed by the research committee on Quantum Engineering under the Atomic Energy Scociety of Japan. (AESJ)

ISSN:1042-0150    

DOI:10.1080/10420159208219822

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Electron microscopy has greatly contributed as a powerful tool in both the characterization and identification of materials in the atomic scale. In these contributions, the most important advantage is it's ability for dynamic study of phenomena, i.e.,in situexperiments. This research has been carried out using high voltage electron microscopes, but some results have been obtained with high resolution electron microscopes under critical conditions. Electron microscopy has been improved further to become an indispensable “Micro-Laboratory” in which formation of various advance materials can also be carried out precisely in the atomic scale. Electron beam science and engineering is a typical example in this research field, and detailed processes of crystalline-amorphous transition and electron irradiation induced foreign atom implantation have been clarified by this method. Recently, new applications to the research fields of non-linear material behavior, such as the behavior of atom clusters and the role of electric dipoles on diffusion, have been carried out.

ISSN:1042-0150    

DOI:10.1080/10420159208219823

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

In order to locate hydrogen dissolved in metals a nuclear reaction1H(11B, α)αα was applied to a channelling method. As an example of this application the results of the following two experiments were briefly reported. (1) The lattice location of H in V was investigated under a <001> compressive stress of 7 kg/mm2below the elastic limit. The configuration of hydrogen is extremely sensitive to compressive stress and changes from a tetrahedral (T) site to a diplaced-Tor 4Tconfiguration. On release of this stress the hydrogen atoms returned toT-sites. (2) To elucidate the mechanism of the enhancement of the terminal solubility for hydrogen (TSH) in Nb on alloying with undersized Mo atoms, the state of hydrogen was studied in Nb-based Nb-Mo dilute alloys. It was demonstrated that H atoms are trapped by Mo atoms and located at sites displaced fromT-sites by about 0.6 Å. This result supports the trapping model for the enhancement of the TSH in the region of low Mo concentration.

ISSN:1042-0150    

DOI:10.1080/10420159208219824

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Vacancy-type defects in ion implanted Si specimens were studied by a monoenergetic positron beam. Dominant defect species in 80-keV B+-implanted specimen were identified as vacancy clusters from their annealing behavior. For 150-keVP+-implanted specimen, oxygen atoms recoiled from a SiO2film grown on Si substrate were found to form stable complexes with vacancy-type defects in the Si substrate near the SiO2/Si interface. Since the migration of vacancy-type defects was blocked by such complexes, the final recovery of defects for the P+-implanted specimen occured at higher annealing temperatures than that for the B+-implanted one. For 2-MeVP+- implanted specimen, two types of oxygen-vacancy complexes were found to coexist even after annealing at 1200°C.

ISSN:1042-0150    

DOI:10.1080/10420159208219825

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

A study has been made of the electric conductivity and structure of Ar ion implanted diamonds depending on the target temperature during Ar implantation. Implantations using 150 keV Ar ions with a dose of 2 × 1016ions/cm2were carried out. The target temperature was maintained either at -60°C or at 200°C. Two types of implanted diamonds were prepared. Each consisting of two implantations was implanted at -60°C, and then at 200°C, whereas the other was implanted at 200°C, and then at -60°C. Each sample was implanted four times in such a way as to use the reversed target temperature. After each implantation, the sheet resistivity was measured by a four point probe method at room temperature, and the structure was investigated by laser Raman spectroscopy. The sheet resistivity varied by two or more orders of magnitude, depending on the target temperature. Raman spectra showed that the surface structure for the specimen implanted at -60°C is amorphous-like, and ion implantation at 200°C reduces disordered-graphite containing amorphous zones. Ar implantation at -60°C in the 200°C-implanted diamond or that at 200°C in -60°C-implanted diamonds results in change in the sheet resistivity and structure which is dependent on the target temperature of additional ion implantation. It is concluded that the target temperature at the final stage of implantation plays an important role in forming different structure in implanted diamonds and results in change the sheet resistivity.

ISSN:1042-0150    

DOI:10.1080/10420159208219826

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Bilayer films of Au(target atom)/α-SiC (substrate) were irradiated with 2 MeV electrons in an ultra-high voltage electron microscope (HVEM), with the electron beam incident on the gold layer. With this irradiation, gold atoms were successfully implanted into the substrate. The implantation process was studied by a combination of HVEM and AES. (1) Irradiation with 2 MeV electrons first induces a crystalline-to-amorphous transition in the α-SiC substrate. (2) Gold atoms which have been knocked-off from the gold layer by the collision with 2 MeV electrons are then injected into the resultant amorphous SiC. (3) The injected gold bonds preferentially with silicon that has uncoupled bonds, and new bonding states are formed between them. (4) With continued irradiation, the gold atoms repeat displacement due to knocking with 2 MeV electrons and subsequent bonding with new silicon atoms which have uncoupled bonds. The repetition of the displacement and the subsequent bonding results in the deep implantation of gold into the SiC substrate.

ISSN:1042-0150    

DOI:10.1080/10420159208219827

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Structural changes of Si(100) locally milled by a 8 keV Ga+focused ion beam were investigated with SEM and TEM. A Ga+beam was focused on a thin section of a TEM specimen and at room temperature made a hole of about 10 μm. The observations were carried out at the region adjacent to the hole. The results of SEM and TEM indicated that a beam affected zone was formed surrounding the hole, where Ga was detected by EDS. TEM photographs also showed flakes of Ga-related film with an orientation relationship with the Si(100) matrix spread in this regime. Analysis of the electron diffraction pattern and the phase relationship of the Si-Ga system indicated the possibility of these flakes being the metastable Ga phase which had interplanar spacing larger than 0.3 nm.

ISSN:1042-0150    

DOI:10.1080/10420159208219828

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Effects of ionized cluster beam (ICB) bombardment on film formation process have been studied in order to understand the unique properties of films grown by this method. By combining the results from cluster size distribution measurements. STM imaging of the initial stages of deposition, and the grown film characteristics, the principal features of ICB is elucidated and the differences between ICB deposition and MBE are clarified. By using a newly developed gas cluster beam system, preliminary results of surface bombarding effect have been obtained.

ISSN:1042-0150    

DOI:10.1080/10420159208219829

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Ion and Electron Beam irradiation effects for Y-Ba-Cu-O and Bi-Sr-Ca-Cu-O superconducting thin films are investigated. By measuring ion and electron dose dependencies of resistivity versus temperature, it became clear that the crystal structure of a Bi system thin film is destroyed with a lower ion and electron dose, than for a Y system thin film. Moreover, it is conformed that the superconducting characteristics for ion and electron beam irradiated films, are recovered by annealing in an O2, atmosphere.

ISSN:1042-0150    

DOI:10.1080/10420159208219830

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor