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Synthesis and Characterization of Desified Amorphous Phasee

Research Project

Project/Area Number 09640569
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeSingle-year Grants
Section一般
Research Field Petrology/Mineralogy/Science of ore deposit
Research InstitutionOsaka University

Principal Investigator

OHTAKA Osamu  Osaka University, Graduate School of Science Associate Professor, 大学院・理学研究科, 助教授 (40213748)

Project Period (FY) 1997 – 1998
Project Status Completed (Fiscal Year 1998)
Budget Amount *help
¥2,800,000 (Direct Cost: ¥2,800,000)
Fiscal Year 1998: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1997: ¥1,800,000 (Direct Cost: ¥1,800,000)
Keywordsglass / high pressure synthesis / densified amorphous / GeO2 / EXAFS / melting
Research Abstract

According to the present research project, we have pefformed following three studies.
1) Glasses of composition GeO_2 and Li_2O-3GeO_2 were compressed up to 30 GPa at temperatures from 27 to 500^oC where sixfold coordination of Ge is stable. Densification of 10 and 15% was achieved for GeO_2 and Li_2O-3GeO_2 glasses, respectively. Ge EXAFS measurements of Li_2O-3GeO_2 glasses retrieved from high pressure indicated that the coordination number of Ge is 4. The second and third neighbor distances (Ge-Gel and Ge-Ge2) determined by EXAFS show that the densification mechanism is explained by more distorted packing of GeO_4 tetrahedra than that in ambient glass. Coordination change by compression in the present Li_2O-3GeO_2 and GeO_2 glasses is reversible. The quenchability of the sixfold coordination of Ge in germanate glass is discussed.
2) Using High-Pressure Differential Thermal Analysis (HP-DTA) system with a cubic multi-anvil high pressure apparatus, we measured the melting points of port … More landite, Ca(OH) _<nu> up to 6GPa and 1000゚C.We detected endothermic due to meeting peaks at the temperature and pressure conditions of 800゚C and 2.5GPa, 769゚C and 3.5GPa, 752゚C and 4.0GPa, 686゚C and 5.0GPa, and 596゚C and 6.0GPa. By in-situ x-ray studies under pressure, the melting of portlandite was observed at 730゚C and 4.32GPa and at 640゚C and 5.81GPa. Results of both HP-DTA and x-ray studies were harmonious within their experimental errors. The melting curve has a negative gradient indicating the higher density of liquid Ca(OH)_2 than that of portlandite in this pressure range.
3) EXAFS spectra near the Ge K-edge in diamond and white-tin type Ge under high temperature and pressure were measured using a cubic anvil type high pressure device with synchrotron radiation from thr Photon Factory. Pressure values up to 10.6GPa were estimated on the basis of the isothermal equation of state of the-diamond type Ge within an accuracy of 0.4GPa. Pressures in the sample cell assembly were also determined by X-ray diffraction experiment using the NaCl scale. The diamond type Ge is of great advantage to the pressure calibrant of EXAFS measurements at elevated temperature because a harmonic approximation can be applied up to 700゚C. Less

Report

(3 results)
  • 1998 Annual Research Report   Final Research Report Summary
  • 1997 Annual Research Report
  • Research Products

    (33 results)

All Other

All Publications (33 results)

  • [Publications] O.Ohtaka et al.: "EXAFS Study of Densified GeO_2 Glasses" Jpn.J.Appl.Phys.(in press).

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] A.Yoshiasa et al.: "Pressure and Temperature Dependence of EXAFS Debye-Waller Factors in Diamond and White-tin type Ge" J.Synchrotron Radiation. 6. 43-49 (1999)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] T.Irifune et al.: "The Postspinel Phase Boundary in Mg_2SiO_4 Determined by in-situ X-ray Diffraction" Science. 279. 1698-1700 (1998)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] T.Nagai et al.: "Pressure-induced Structural Modifications of Germanate at Room Temperature : In-situ XRD and EXAFS studies" Geophysical Monograph. 101. 385-391 (1998)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] Y.Matsumoto et al.: "Pressure Induced Structural Phase transition of CdI_2-type PbI_2" Rev.High Pressure Sci.Technol.7. 341-343 (1998)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] O.Ohtaka et al.: "Phase Equilibria for the Fe_2SiO_4-Fe_3O_4 System under Pressure" Phys.Chem.Minerals. 24. 555-560 (1997)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] S.Kikkawa et al.: "Tetranoral LaN and Its New La-B-N Ternary Reaction Product Prepared under High Pressure" J.Euro.Ceram Soc. 17. 1831-1835 (1997)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] T.Nagai et al.: "Kinetic Studies of the a-quartz-coecite transformation of SiO2" Mineral.J. 19. 147-154 (1997)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] O.Ohtaka.et al: "In situ Observation of ZrO2 Phases at High Pressure and Temperature" Geophysical Monograph. 101. 429-433 (1998)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] T.Nagai et al: "Nucleation and Growth kinetic of the a-Quartz-Coecite Transformation Using both Powder and Single Crystal Samples" Rev.High Pressure Sci.Technol. 7. 125-127 (1988)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] T.Yamanak et al: "Phase Relation in the System.of Fe2SiO_4-Fe3O_4 Solid Solution under Pressure up to 10GPa and their Strucures and Physical Properties of Magnetism and Electric Conductivity" Geophysical Morograph. 101. 451-459 (1998)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] H.Fukui et al: "Phase Relations of Portlardite under Pressure"

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] O.Ohtaka, H.Tobe and T.Yamanaka: ""Phase Equilibria for the Fe2SiO4-Fe3O4 System under High Pressure"" Phys.Chem.Minerals. 24. 555-560 (1997)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] S.Kikkawa, T.Ohmura, M.Takahashi, F.Kanamaru and O.Ohtaka: ""Tetragonal LaN and Its New La-B-N Ternary Reaction Product Prepared under High Pressure"" J.Euro.Ceram.Soc.17. 1831-1835 (1997)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] T.Nagai, O.Ohtaka and T.Yamanaka: ""Kinetic Studies of the a-quartz-coecite transformation of SiO2"" Mineral.J.19. 147-154 (1997)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] O.Ohtaka, T.Nagai, T.Yamanaka, T.Yagi and O.Shimomura: ""In situ Observation of ZrO2 Phases at High Pressure and Temperature"" Properties of Earth and Planetary Materials at High Pressure and Temperature, edt by M.H.Manghnani and T.Yagi, Geophysical Monograph. 101. 429-433 (1998)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] Y.Matsumoto, O.Ohtaka, M.Kikuchi, T.Nagai, T.Yamanaka and O.Shimomura: ""Pressure Induced Structural Phase Transition of Cdl2-type Pb12"" Rev.High Pressure Sci.Technol.Vol.7. 341-343 (1988)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] T.Nagai, S.Mori, O.Ohtama and T.Yamanaka: ""Nucleation and Growth Kinetic of the a-Quartz-Coecite Transformation Using both Powder and Single Crystal Samples"" Rev.High Pressure Sci.Technol.Vol.7. 125-127 (1988)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] T.Nagai, O.Ohtaka, A.Yoshiasa, T.Yamanaka and O.Shimomura: ""Pressure-induced Structural Modifications of Germanates at Room Temperature : In Situ XRD and EXAFS Studies "" Properties of Earth and Planetary Materials at High Pressure and Temperature, edited by M.H.Manghnani and T.Yagi, Geophysical Monograph. 101. 385-391 (1998)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] T.Yamanaka, H.Tobe, H.Shimazu, Y.Dobuchi, O.Ohtaka and T.Nagai: ""Phase Relation in the System of Fe2SiO4-Fe3O4 Solid Solution under Pressure up to 10GPa and their Strucures and Physical Properties of Magnetism and Electric Conductivity"" Properties of Earth and Planetary Materials at High Pressure and Temperature, edt by M.H.Manghnani and T.Yagi, Geophysical Monograph. 101. 451-459 (1998)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] T.Irifune, N.Nishiyama, K.Kuroda, T.Inoue, M.Isshiki, W.Utsumi, K.Funakoshi, S.Urakawa, T.Uchida, T.Katsura, and O.Ohtaka: ""The Postspinel Phase Boundary in Mg2SiO4 Determined by in-situ X-ray Diffraction"" Science. 279. 1698-700 (1998)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] A.Yoshiasa, T.Nagai, o.Ohtaka, O.Kamishima, and O.Shimomura: ""Pressure and Temperature Dependence of EXAFS Debye-waller Factors in Diamond Type and White-tin Type Germanium"" J.Synchrotron Radiation. 6. 43-49 (1999)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] O.Ohtaka, M.Kikuchi, K.Nakajima, A.Yoshiasa and T.Yamanaka: ""EXAFS Study of Densified GeO2 Glasses"" Jpn.J.Appl.Phys.(in press). (1999)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] H.Fukui, O.Ohtaka: ""Phase Relations of Portlandite under Pressure"" Phys.Earth Planetary Interior. submitted. (1999)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] O. Ohtaka et al.: "EXAFS Study of Densified GeO_2 Glasses" Jpn. J. Appl. Phys.in press. (1999)

    • Related Report
      1998 Annual Research Report
  • [Publications] A. Yoshiasa et al.: "Pressure and Temperature Dependence of EXAFS Debye-waller Factors in Diamond and white-tin Type Germanium" J. Synchrofron Radiation. 6. 43-49 (1999)

    • Related Report
      1998 Annual Research Report
  • [Publications] H. Fukui et al.: "Phase Relations of Portlandite under High Pressure" Proc. SEDI 98 (The 6thsymposium of study of the Earth's Deep Interior). 101-101 (1998)

    • Related Report
      1998 Annual Research Report
  • [Publications] Y.Matsumoto et al.: "Pressure induced phase transitions of CdI_2-type PbI_2" Proceedings AIRAPT 97. 1 (in press). (1998)

    • Related Report
      1997 Annual Research Report
  • [Publications] O.Ohtaka et al.: "In situ observation of 2rO_2 phaseses at high pressure and temperature" High pressure research in mineral physics edited by M.H.Manghnani and T.Yagi. (in press). (1998)

    • Related Report
      1997 Annual Research Report
  • [Publications] T.Nagai et al.: "Kinetic Studies of the α-quartz-coecite transformation of SiO2" Mineral J.19. 147-154 (1997)

    • Related Report
      1997 Annual Research Report
  • [Publications] T.Irifune et al.: "The postspinel phase boundary in Mg_2SiO_4 determined by in-situ x-ray diffraction" Science. 279. 1698-1700 (1998)

    • Related Report
      1997 Annual Research Report
  • [Publications] O.Ohtaka et al.: "Phase equilibria for the Fe_2SiO_4-Fe_3O_4 system under high pressure" Phys.Chem.Minerals. 24. 555-560 (1997)

    • Related Report
      1997 Annual Research Report
  • [Publications] T.Nagai et al.: "Pressure-induced structural modifications of Germanates under high pressure at room temperature detected by high P-EAXFS" High Pressure research in Mineral Physics edited by M.H.Manghnani and T.Yagi. (in press). (1998)

    • Related Report
      1997 Annual Research Report

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Published: 1997-04-01   Modified: 2016-04-21  

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