特集-ダイアモンドの高圧合成- Rev. High Pressure Sci. Technol. 8-3,147-154(1998) |
放射光蛍光X線分析を用いる合成ダイヤモンドの不純物解析 Characterization of Impurities in Synthetic Diamonds by Using Synchrotron Radiation X-ray Fluorescence Analysis |
早川 慎二郎 賈 暁鵬* 合志 陽一 若槻 雅男* HAYAKAWA Shinjiro JIA Xiao-Peng GOHSHI Yohichi WAKATSUKI Masao |
Trace impurities in synthetic diamonds are
characterized by using a scanning x-ray microprobe
with synchrotron radiation. The diamond crystals
analyzed were grown under high pressure and
high temperature with the various metalic
solvents. Utilizing synchrotron radiation
(SR) x-ray fluorescence (XRF) analysis, concentrations
of trace impurities down to 0.1 ppm can be
evaluated. Moreover, the x-ray energy dependence
of XRF yield around the absorption edge shows
the near-edge x-ray absorption fine structure
of the trace impurities, which provides chemical-state
information on the trace impurities in the
diamond crystal. The future expectation of
analytical capability with the next generation
synchrotron light source is also described. [diamond, x-ray fluorescence, impurity, synchrotron radiation, x-ray absorption fine structure] |
〒113-8656 東京都文京区本郷7-3-1 東京大学大学院工学系研究科応用化学専攻 Department of Applied Chemistry, The University of Tokyo, Hongo, Bunkyo, Tokyo 113-8656 *〒305-0006 つくば市天王台1-1-1 筑波大学物質工学系 Institute of Materials Science, Univ. of Tsukuba, Tsukuba, Ibaraki 305-0006, Japan |
特集-ダイアモンドの高圧合成- Rev. High Pressure Sci. Technol. 8-3,155-162(1998) |
合成ダイヤモンドの不純物と光学特性 Impurities and Optical Properties of Synthetic Diamond |
神田 久生 KANDA Hisao |
Pure diamond has no absorption bands in a
wide range of wave lengths from ultraviolet
to infrared. However, diamond crystals show
some colors usually, although most of them
are nonattractive yellow or brown. Diamond
crystals also give off a variety of luminescence
with stimulation from an electron beam, UV
light, etc. The colors are produced by the
incorporation of impurities. In the case
of diamond, the impurities which are incorporated
are limited. They are nitrogen, boron, nickel,
cobalt, silicon and phosphorus. The color
features of high pressure synthetic diamonds
are described in terms of the impurities. [diamond, single crystal, impurity, optical property, optical absorption, luminescence, color, defect] |
〒305-0044 つくば市並木1-1 無機材質研究所 National Institute for Research in Inorganic Materials( NIRIM ), 1-1 Namiki, Tsukuba, Ibaraki 305-0044 |
特集-ダイヤモンドの高圧合成- Rev. High Pressure Sci. Technol. 8-3,163-170(1998) |
ダイアモンド溶融相からの材料合成 Materials Synthesized from Molten Diamond |
都賀谷 素宏 TOGAYA Motohiro |
Liquid carbon was formed by the melting of
diamond and the metastable melting of graphite
in the diamond stable regions at 15 and 18
GPa. The diamond crystallized by cooling
the molten carbon was investigated by visible
and ultraviolet absorption spectra, cathodoluminescence
(CL) and transmission electron microscopy
(TEM). The diamond contains nitrogen and
is classified as Type I. The color centers
of blue band A, green band A, H3, 575 nm
and N3 were found and a vacancy-type dislocation
loop and a cavity with a cuboctahedral shape
were observed in the diamond. The solidification
behaviors of a diamond from the molten C-BN
and C-aluminosilicate are also discussed.
[melting, metastable melting, graphite, diamond, liquid carbon, crystallization, absorption spectra, cathode luminescence, transmission electron spectroscopy, color center, dislocation loop, cavity, C-BN system, C-aluminosilicate system] |
〒560-8531 豊中市待兼山町1-3大阪大学 Osaka University, 1-3 Matikaneyama-cho Toyonaka 560-8531 |
特集-ダイアモンドの高圧合成- Rev. High Pressure Sci. Technol. 8-3,171-176(1998) |
cBN単結晶の高圧合成 Synthesis of a cBN Single Crystal under High Pressure |
谷口 尚 TANIGUCHI Takashi |
A single crystal of cubic boron nitride(cBN)
was grown under the high-pressure and high-temperature
conditions of 5.5 GPa and 1500-1700 for 10
min.-100 h. A temperature gradient method
was employed for the crystal growth by using
lithium boron nitride as a solvent. In order
to characterize the growth features of cBN
single crystal on seed surfaces, large seeds
of diamond crystals were employed, and the
heteroepitaxial growth of cBN on (100) and
(111) diamond surfaces was studied. The initial
growth feature of the cBN crystal was found
on the diamond seed surface after a growing
time of 10 min. On the (100) seed surface,
typical anti-phase boundaries were exhibited
in the grown crystals, while they were not
seen in crystals grown on a (111) surface.
Two types of growth features such as (111)
and (113) facetted growth typically appeared
in the grown crystal on the (111) surface.
Considering the growth process under a constant
P-T growing condition, the growth rate of
cBN crystal was significantly small as compared
to that of diamond. [cBN single crystal, diamond seed, temperature gradient method, heteroepitaxial growth, anti-phase boundary] |
〒305-0044 茨城県つくば市並木1-1 科学技術庁 無機材質研究所 National Institute for Research in Inorganic Materials, 1-1 Namiki Tsukuba, Ibaraki 305-044 Japan |
特集-ダイヤモンドの高圧合成- Rev. High Pressure Sci. Technol. 8-3,177-184(1998) |
B-C-N系物質の低圧相と高圧相の合成研究 Syntheses of Low-Pressure and High-Pressure Phases in the B-C-N System |
佐々木 高義 SASAKI Takayoshi |
This article reviews recent progress in the
syntheses of B-C-N ternary materials. A number
of B-C-N graphites of various stoichiometry
have been synthesized via chemical vapor
deposition and pyrolysis of precursors. One
of the typical compositions, BC2N, has been relatively well-characterized,
revealing that it is a genuine B-C-N compound
with a semiconductive nature with a bandgap
around 2 eV. Static and dynamic compressions
on the B-C-N graphites have been conducted
to explore the phase relationship and stability
of B-C-N high-pressure phases. The results
from these studies can systematically be
understood by the fact that segregation into
diamond and cBN is thermodynamically favored
rather than formation of a B-C-N diamond-like
compound. [B-C-N ternary system, hybrid compounds, graphite-like materials, semiconductor, diamond-related phases, superhard materials] |
〒305-0044 茨城県つくば市並木1-1 科学技術庁
無機材質研究所 National Institute for Research in Inorganic Materials, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 |
特集-ダイアモンドの高圧合成- Rev. High Pressure Sci. Technol. 8-3,185-192(1998) |
B-O系超硬物質の合成と焼結 Synthesis and Sintering of Super-hard Materials in the B-O System |
伊藤 秀章 ITOH Hideaki |
A brief historical review of research concerning
super-hard materials in the boron suboxide
system is described with an emphasis on the
synthesis and sintering of hexaboronoxide
(B6O). Authors' investigations of the preparation
of B6O-based super-hard materials are also described
along with the formation behavior of B6O
powder in a high temperature reaction between
amorphous boron and B2O3. The structure and properties of the single
phase B6O sintered compact obtained under high pressure
are discussed in reference to the literature.
The sintered composites in the B6O-B4C and B6O-cBN systems were prepared under high pressure
and temperature conditions (3-6 GPa, 1500-1800Åé).
The mechanical properties (hardness and toughness)
and chemical stability are related to the
phase relationship in the above quasi-two
component systems and the microstructures
of sintered composites. [boron suboxide, high pressure sintering, super-hard boron compounds, sintered composites] |
〒464-8603 名古屋市千種区不老町名古屋大学理工科学総合研究センター Center for Integrated Research in Science and Engineering, Nagoya University, Chikusa-ku, Nagoya 464-8603 |
トピックス Rev. High Pressure Sci. Technol. 8-3,193-208(1998) |
電子移動反応と高圧化学 Electron Transfer Reactions at Elevated Pressures |
高木 秀夫 TAKAGI Hideo |
The theory of outer-sphere electron tranfer
processes has been developed by many scientists
since the first publication by Libby in 1952
referring to the role of the solvent. After
the establishment of Marcus Theory, the electron
transfer reactions have been analysed on
the basis of activation free energy, provided
that the inner-sphere and outer-sphere changes
are concerted. However, this approach was
proved to be rather inaccurate because of
the uncertainties in the estimation of the
inner-sphere contribution to the activation
free energy. A recent development of the
analyses based on the volume profiles of
reactions, however, proved that the more
accurate interpretation of the outer-sphere
electron transfer processes is possible as
the uncertainty related to the inner-sphere
contribution diminishes. Theoretical treatment
and the application of the "volume analysis"
to various outer-sphere reactions are summarized
in this review, together with an application
of the volume analysis to the "Gated"
electron transfer processes. [electron transfer, theory and application, mechanism, activation volume, reaction volume, elevated pressure] |
〒464-8602 名古屋市千種区不老町 名古屋大学大学院理学研究科物質理学専攻無機・分析化学大講座 Inorganic and Analytical Chemistry Division, Department of Chemistry and Physics, Graduate School of Sciences, Nagoya University, Furocho, Chikusa-ku, Nagoya, 464-8602 Japan |
〒606-0805
京都市左京区下鴨森本町 15 (財)生産開発科学研究所内
日本高圧力学会事務局
Tel (075)721-0376 Fax (075)723-9629
koatsu@mbox.kyoto-inet.or.jp