Sumitomo Electric Industries, Limited

Shuichi Satoh

Kazuwo Tsuji

Hitoshi Sumiya

Takeru Nakashima

Shuji Yazu

Nobuo Urakawa

Akito Yoshida

Yoshiki Nishibayashi

Yasuyuki Kanada

Naohiro Toda

Yasushi Goda

Yosio Nisida

Yuzo Demizu

Masuo Nakagawa

Kiyofumi Muro

Yasushi Gouda

Moritami Okada

Process for the synthesis of diamond

A high purity synthetic diamond with less impurities, crystals defects, strains, etc. can be provided, in which the nitrogen content is at most 10 ppm, preferably at most 0.1 ppm and the boron content is at most 1 ppm, preferably at most 0.1 ppm or in which nitrogen atoms and boron atoms are contained in the crystal and the difference between the number of the nitrogen atoms and that of the boron atoms is at most 1.times.10.sup.17 atoms/cm.sup.3. The strain-free synthetic diamond can be produced by a process for the production of a strain-free synthetic diamond by the temperature gradient method, which comprises using a carbon source having a boron content of at most 10 ppm and a solvent metal having a boron content of at most 1 ppm and adding a nitrogen getter to the solvent metal, thereby synthesizing the diamond.

Process for the production of synthetic diamond

A synthetic single crystal diamond for wire drawing die; the process of manufacturing it and a wire drawing die to utilize it are disclosed. At least one plane of the diamond for wire drawing die is a cleavage plane of (111) faces, and the drawing hole of wire drawing die lies vertical to the cleavage plane. The diamond for the wire drawing die is produced by providing a synthetic single crystal having 20-400 ppm nitrogen of Ib type diamond. A groove is made on the diamond surface parallel to (111) faces employing energy beams such as a laser beam, an ion beam and an electron beam. A wedge is struck into the groove to cleave the diamond, and a plate is obtained. Furthermore, the plate is divided into polyhedrons, employing either an energy beam or a blade. The cleavage plane of the polyhedron is almost parallel to the (111) faces of crystal, therefore the cleavage plane is used as the standard plane to build the drawing hole.

Synthetic single crystal diamond for wiring drawing dies and process for

An improved diamond sintered body having an excellent breakage resistance, corrosion resistance, heat resistance and wear resistance and capable of being sintered at a relatively low pressure and low temperature can be provided. The feature thereof consists in a diamond sintered body comprising 50 to 99.9 volume % of diamond and the balance of a binder phase consisting of a single or mixed phase of a compound (C) or composite (C') of at least one element (A) selected from the group consisting of rare earth elements, Group 3B, 4A, 4B and 6B elements of Periodic Table, iron group, Mn, V, alkali metals and alkaline earth metals with a phosphorus compound (B), or of the above described compound (C) or composite (C') with an oxide of (A).

Diamond sintered body and a process for the production of the same,

A colorless, transparent low defect density, synthetic type IIa diamond single crystal, in which the etch pits due to needle-shaped defects are at most 3.times.10.sup.5 pieces/cm.sup.2, and which can be applied to uses needing high crystallinity of diamond, for example, monochromators, semiconductor substrates, spectroscopic crystals in X-ray range, electronic materials, etc., is provided by a process for the production of the colorless, transparent low defect density, synthetic diamond single crystal by growing new diamond crystal on a seed crystal of diamond by the temperature gradient method which comprises using a crystal defect-free diamond single crystal, as a seed crystal of diamond, and optionally subjecting to a heat treatment in a non-oxidizing atmosphere at a low pressure and a temperature of 1100 to 1600.degree. C.

Low defect density diamond single crystal and a process for the

The present invention provides a diamond sintered compact having a higher strength as well as more excellent heat resistance, breakage resistance and corrosion resistance, as compared with those of the prior art, which thus can effectively be applied to tool materials for cutting or polishing of non-ferrous metals or ceramics, and edge materials of drill bits for excavating petroleum. The feature of the diamond sintered compact contains 0.1 to 30 volume % of at least one compound containing at least one element selected from the group consisting of silicon and titanium, and oxygen and the balance of diamond, for example, a titanate of a metal selected from the group consisting of iron, cobalt, nickel and manganese.

Diamond sintered compact and a process for the production of the same

Synthetic single crystal diamond for wire drawing dies

An infrared optical part comprised of a synthetic diamond single crystal, and a method of making the same. The infrared optical part is comprised of a synthetic diamond having a nitrogen content of not more than 5 ppm and a boron content of not more than 3 ppm, wherein the parallelism between its light incident and reflecting surfaces is not more than one minute. The infrared optical part is used as a window member in infrared spectral analysis. It is also used in the form of a pair of anvils for holding a sample therebetween in connection with the measurement of transmitted light that has passed through the sample after the sample is compressed. The part is also used in the form of an infrared ATR prism. The method involves the steps of abrading an infrared optical part having the above mentioned nitrogen and boron content by a grinder, measuring the parallelism between the light incident and reflecting surfaces of the part by laser light, and smoothing the grinding apparatus, whereby the parallelism is set to a level of not more than 2.91.times.10.sup.-4 radians.

Infrared optical element and method of making the same

A hole-burning material which comprises at least one hole which is formed on a zero-phonone line and semi-permanently lasts without suffering from any change in the temperature range from 2 to 120 K. and which can be erased by irradiation of excited light having an energy larger than the zero-phonone line, in which the burnt holes have long life and deep depth and any single holes can be erased.

Hole-burning material and production thereof

A green diamond has a nitrogen content in its crystals within the range of 5.times.10.sup.16 to 3.times.10.sup.19 atoms/cm.sup.3, an absorption coefficient of H2 centers at a wavelength of 800 nm within the range of 0.3 to 6 cm.sup.-1, an absorption coefficient of the Ib type nitrogen at a wavelength of 500 nm within the range of 0.05 to 1.5 cm.sup.-1, and absorption coefficients of H3 centers, H4 centers, N-V centers and GR1 centers in the visible region of not more than 0.2 cm.sup.-1. Such green diamonds are produced by preparing a clear-yellow Ib type diamond having a nitrogen content in crystals within the range of 5.times.10.sup.16 to 3.times.10.sup.19 atoms/cm.sup.3, irradiating this diamond with an electron beam having not less than 1.times.10.sup.18 electrons/cm.sup.2 at an accelerating voltage of 2 to 4 MeV, and subjecting the diamond to a heat treatment at a temperature of 1500.degree. C.-1800.degree. C. in a vacuum of not more than 10.sup.-3 torr.

Green diamond and method of producing the same

A method of manufacturing a diamond laser crystal having an excellent laser efficiency is performed by first, preparing a synthetic type Ib diamond containing at least 60 volume percent of a (111) plane growth sector (43) is prepared. This synthetic diamond is then thermally treated under high temperature/high pressure, so that type Ib nitrogen contained in the synthetic diamond is converted to type IaA nitrogen. Thereafter an electron beam is applied to the synthetic diamond in order to generate vacancies in the synthetic diamond. Finally annealing is performed on the synthetic diamond to form H3 centers by coupling the type IaA nitrogen atoms contained in the synthetic diamond, with the vacancies. According to this method, the H3 centers can be formed in the synthetic type Ib diamond at high concentration, while formation of NV centers which become an obstacle to laser action, can be suppressed.

Diamond laser crystal and method manufacturing the same

A purple diamond has an absorption coefficient of the Ib type nitrogen at 500 nm, within the range of 0.2-2 cm.sup.-1, an absorption coefficient of the N-V center at an absorption peak of 570 nm, within the range of 0.3-10 cm.sup.-1, and absorption coefficients of the GR1 center, H2 center, H3 center, and H4 center which are less than 0.2 cm.sup.-1 in the visible region. A method of producing such a purple diamond uses as a starting material an Ib type artificial synthetic diamond crystal wherein the Ib type nitrogen content in the crystal is within the range of 8.times.10.sup.17 -1.4.times.10.sup.19 atoms/cm.sup.3, such a starting material is subjected to an electron beam irradiation of 5.times.10.sup.16 -2.times.10.sup.18 electrons/cm.sup.2 at 2-4 MeV, and then annealing the irradiated diamond in a vacuum of less than 10.sup.-2 Torr, at a temperature of 800.degree.-1100.degree. C. for more than 25 hours.

Purple diamond and method of producing the same

A diamond laser formed of a synthetic diamond provides a high output power and a variable wavelength in the near infrared region. The maximum value of the optical density of H2 centers in the direction of the pumping light is in the range of 0.01 to 4. Laser action is caused in the range of 1000 to 1400 nm by an external pumping light at 650 to 950 nm. Such a diamond laser is produced by preparing a synthetic Ib type diamond having a nitrogen concentration within the range of 1.times.10.sup.17 to 8.5 10.sup.19 atoms/cm.sup.3, subjecting this synthetic diamond to an electron irradiation with a dose of not less than 5.times.10.sup.17 electrons/cm.sup.2, and heat-treating the synthetic diamond in a vacuum of not more than 1 Torr or in an inert gas atmosphere and at a temperature within the range of 1400.degree. to 1850.degree. C. If the threshold value of the pumping light intensity necessary for causing laser action is Ith then, to make the pumping light intensity I greater than Ith throughout the laser crystal, it is important, that the maximum value of the optical density of H2 is within the range between 0.01 and 4.

Diamond laser, method for producing the same, and method for activating

A process for synthesizing a large diamond having a diameter of 8 mm or more by the temperature gradient method, wherein a (111) or (100) surface of a seed crystal having a diameter of 3 mm or more is used as a growing surface, the entire area of the growing surface is first dissolved in the diamond-stable region before crystal growth is started, the crystal growth is effected using a plug of a solvent in which the height of the central portion thereof is higher than the height of the peripheral portion thereof, the plug of a solvent has a planar or curved surface on the side where the plug of a solvent contacts a carbon source during the crystal growth, and the crystal growth is effected under such pressure and temperature conditions that the growth of the (111) or (100) surface is predominant.

Process for synthesizing large diamond

A synthetic diamond heat sink which can be easily shaped and which ensures a consistently high thermal conductivity in which the diamond is a Type Ib diamond containing 50 to 100 ppm nitrogen. The synthetic diamond crystal has a shape similar to the crystal structure of a hexahedron synthesized by heating a carbon source, a solvent and a diamond seed crystal and the stability region of diamond at a high pressure. The resulting temperature gradient between the carbon source and seed crystal is adjusted to cause diamond growth on the seed crystal. The solvent employed is selected from the group of cobalt, nickel, iron, chromium and manganese. The diamond crystal is caused to grow as the temperature of the solvent is gradually decreased at a rate of 0.15 to 10.degree. C. per hour so that the temperature of the seed crystal and growning diamond crystal is within a range the lower limit of which is a temperature 20.degree. C. higher than the melting point of the solvent and carbon source system and the upper limit of which is a temperature 40.degree. C. higher than the lower limit.

Growing community of inventors

Itami, Japan

Shuichi Satoh