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US4950463A
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Purple diamond and method of producing the same
Assignee: Sumitomo Electric Industries Ltd
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Filing: 1988-11-17
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Granted: 1990-08-21
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Expires: 2008-11-17
Abstract
Abstract A purple diamond has an absorption coefficient of the Ib type nitrogen at 500 nm, within the range of 0.2-2 cm -1 , an absorption coefficient of the N-V center at an absorption peak of 570 nm, within the range of 0.3-10 cm -1 , and absorption coefficients of the GR1 center, H2 center, H3 center, and H4 center which are less than 0.2 cm -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 8×10 17 -1.4×10 19 atoms/cm 3 , such a starting material is subjected to an electron beam irradiation of 5×10 16 -2×10 18 electrons/cm 2 at 2-4 MeV, and then annealing the irradiated diamond in a vacuum of less than 10 -2 Torr, at a temperature of 800°-1100° C. for more than 25 hours.
Inventors
- 👤 Shuichi Satoh
- 👤 Kazuwo Tsuji
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 16:11
CPC Classifications
B; B28; B28D; B28D5/00; C; C30; C30B; C30B29/00; C30B29/02; C30B29/04; C30B33/00
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
121 words
A diamond, comprising an Ib-type synthetic diamond crystal having an Ib-type nitrogen content in the crystal within the range of 8×10 17 to 1.4×10 19 atoms/cm 3 , and a first absorption coefficient of Ib-type nitrogen at 500 nm, within the range of 0.2-2 cm -1 , a second absorption coefficient of the N-V center at an absorption peak of 570 nm, within the range of 0.3-10 cm -1 , and third absorptin coefficients of the GR1 center, the H2 center, the H3 center, and the H4 center of less than 0.2 cm -1 , in the visible region, said first and second absorption coefficients assuring a transparency of said diamond, said third absorption coefficients assuring a distinct purple color brilliance.
Claim 2
Dependent Claim
121 words
A diamond, comprising an Ib-type synthetic diamond crystal having an Ib-type nitrogen content in the crystal within the range of 8×10 17 to 1.4×10 19 atoms/cm 3 , and a first absorption coefficient of Ib-type nitrogen at 500 nm, within the range of 0.2-2 cm -1 , a second absorption coefficient of the N-V center at an absorption peak of 570 nm, within the range of 0.3-10 cm -1 , and third absorptin coefficients of the GR1 center, the H2 center, the H3 center, and the H4 center of less than 0.2 cm -1 , in the visible region, said first and second absorption coefficients assuring a transparency of said diamond, said third absorption coefficients assuring a distinct purple color brilliance.
Claim 3
Independent Claim
175 words
A method of producing a diamond, comprising the following steps: (a) using an Ib-type synthetic diamond crystal having an Ib-type nitrogen content in the crystal within the range of 8×10 17 -1.4×10 19 atoms/cm 3 , (b) subjecting said diamond crystal to an electron beam irradiation of 5×10 16 -2×10 18 electrons/cm 2 at 2 to 4 MeV, and (c) annealing in a vacuum of less than 10 -2 Torr at a temperature of 800°-1100° C. for more than 25 hours, for producing a transparent diamond having a distinctly purple color brilliance, whereby said diamond crystal has a first absorption coefficient of Ib-type nitrogen at 500 nm, within the range of 0.2-2 cm -1 , a second absorption coefficient of the N-V center at an absorption peak of 570 nm, within the range of 0.3-10 cm -1 , and third absorption coefficients of the GR1 center, the H2 center, the H3 center, and the H4 center of less than 0.2 cm -1 , in the visible region for achieving said transparent distinctly purple color brilliance.
Claim 4
Independent Claim
175 words
A method of producing a diamond, comprising the following steps: (a) using an Ib-type synthetic diamond crystal having an Ib-type nitrogen content in the crystal within the range of 8×10 17 -1.4×10 19 atoms/cm 3 , (b) subjecting said diamond crystal to an electron beam irradiation of 5×10 16 -2×10 18 electrons/cm 2 at 2 to 4 MeV, and (c) annealing in a vacuum of less than 10 -2 Torr at a temperature of 800°-1100° C. for more than 25 hours, for producing a transparent diamond having a distinctly purple color brilliance, whereby said diamond crystal has a first absorption coefficient of Ib-type nitrogen at 500 nm, within the range of 0.2-2 cm -1 , a second absorption coefficient of the N-V center at an absorption peak of 570 nm, within the range of 0.3-10 cm -1 , and third absorption coefficients of the GR1 center, the H2 center, the H3 center, and the H4 center of less than 0.2 cm -1 , in the visible region for achieving said transparent distinctly purple color brilliance.
Claim 5
Dependent Claim
17 words
The method of claim 2, wherein said synthetic diamond crystal is synthesized by a temperature gradient method.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-08-20 | 1994-02-19 | 1994-08-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-08-20 | 1998-02-19 | 1998-08-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-08-20 | 2002-02-19 | 2002-08-21 | $7700.00 | Window Closed / Lapsed |