1994 Fiscal Year Final Research Report Summary
Properties of Glass Implanted with Phosphorus for Radiotherapy
| Project/Area Number |
04559005
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| Research Category |
Grant-in-Aid for Developmental Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
広領域
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
KOKUBO Tadashi Kyoto University, Fac.of Engin., Professor, 工学部, 教授 (30027049)
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| Co-Investigator(Kenkyū-buntansha) |
EBISAWA Yukihiro Sumitomo Metal Co.Ltd., Assist councilor, 事業開発本部, 参事補
HIRAOKA Masahiro Kyoto University, Fac.of Med., Assist.Professor, 医学部, 助教授 (70173218)
YAMADA Isao Kyoto University, Fac.of Engin., Professor, 工学部, 教授 (00026048)
MIYAJI Fumiaki Kyoto University, Fac.of Engin., Instructor, 工学部, 助手 (80219782)
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| Project Period (FY) |
1992 – 1994
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| Keywords | Radiotherapy / Ion implantation / Phosphorus / Silica glass / Cancer / Chemical durability / Rutherford backscattering / FT-IR spectra |
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| Research Abstract |
Highly pure silica glass implanted with phosphorus ion at 30keV by 5*10^<16>cm^<-2> dissolved almost all the phosphorus into the pure water at 95ﾟC during 7days. When this glass was heated at 400ﾟC in H_2 atmosphere and then heated at 900ﾟC in O_2 atmosphere, phosphorus in the glass became insoluble into the water. This suggests that phosphorus colloid grew by the heat treatment at 400ﾟC and that colloids were encapsulated in a thin SiO_2-P_2O_5 glass layr by the heat treatment at 900ﾟC.When the silica glass was implanted with nitrogen ion as well as phosphorus ion, and then subjected to the same heat treatment, highly phosphorus-containing silica glass with high chemical durability was obtained, since the evaporation of phosphorus on the heat treatment was suppressed by formation of silicon oxynitride. When the phosphorus ion was implanted to the silica glass at 50keV by 5*10^<16>cm^<-2>, it showed the maximum concentration at about 50nm depth and did not distribute up to the glass surface. As a result, this glass did not dissolve the phosphorus into the water in spite of the surface structural damage caused by the ion implantation. Moreover, the silica glass implanted with phosphorus ion at 200keV did not dissolve phosphorus even if a large dose of phosphorus, 1*10^<18>cm^<-2>, was implanted. It is expected that the glass obtained by the present method is useful for deep cancer treatments.
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