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Crystallographic and Thermodynamic Study on the Martensitic Transformations in Nanometer-sized Particles of Alloys

Research Project

Project/Area Number 15560574
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeSingle-year Grants
Section一般
Research Field Physical properties of metals
Research InstitutionOsaka Prefecture University (2005)
Osaka Women's University (2003-2004)

Principal Investigator

TADAKI Tsugio  Osaka Prefecture University, Graduate School of Science, Professor, 理学系研究科, 教授 (90029885)

Project Period (FY) 2003 – 2005
Project Status Completed (Fiscal Year 2005)
Budget Amount *help
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2005: ¥1,300,000 (Direct Cost: ¥1,300,000)
Fiscal Year 2004: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 2003: ¥1,100,000 (Direct Cost: ¥1,100,000)
Keywordsmartensitic transformation / nanoparticles of alloys / size effect / crystal structure / transmission electron microscopy / electron diffraction / 透過電子顕微鏡観察 / 電子回折
Research Abstract

At the first stage of the present study, we have discussed in thermodynamic points of view the depressions of the martensitic transformation temperatures in nanoparticles previously observed for Au-Cd and Fe-Ni alloys, compared with those for the corresponding bulk, where T_0 temperature is reduced, while it remains almost unchanged, respectively ; and proposed thermodynamic conditions for the occurrences : (Δs^<P→M>)_<bulk> < (Δs^<P→M>)_<particle> for Au-Cd, and (Δs^<P→M>)_<bulk> 【approximately equal】 (Δs^<P→M>)_<particle> and (Δh^<P→M>)_<bulk> 【approximately equal】 (Δh^<P→M>)_<particle> for Fe-Ni.
Next, we have tried to prepare nanoparticles of Fe-x at.%Pt(x【less than or equal】25) alloys following a chemical synthesis method by which Sun et.al. succeeded in making monodispersed nanoparticles of Fe-Pt alloys near equiatomic composition (Science, 2000). At the beginning, following their method, iron pentacarbonyl (Fe(CO)_5) and platinum acetylacetonate (Pt(acac)_2) were used as raw mate … More rials for the component metals, and at the second step, instead of the toxic Fe(CO)_5, iron acetylacetonate (Fe(acac)_3) was adopted. Identification of the product phases in as-synthesized and subsequently heat-treated specimens were made by means of CTEM, HRTEM, ED and analytical TEM.
As-synthesized specimens were confirmed to consist of fairly monodispersed particle-like products with nanometer size. Unexpectedly, however, the products were not of alloys with nominal compositions, but were the mixture of Pt-rich γ phase Pt-Fe alloys near pure Pt and an Fe oxide Fe_3O_4, their relative amounts depending on nominal composition. This indicates that alloying of Fe and Pt hardly occurs at the reflux condition near 560K
Alloying of Fe and Pt proceeded upon heating up to 1073K in TEM and the products at room temperature after heating were particles of only Fe-rich γ phase or a mixture of α and Fe-rich γ phases. The size of the α and γ phase alloy particles were increased up to about 15 nm.
To be noticed was that the γ phase alloy particles with compositions less than 10at.%Pt remained untransformed at room temperature and even at 103K.
Therefore it is experimentally made clear that the γ phase of the Fe-Pt alloy is by more than 500K stabilized in the nanoparticles, compared with the corresponding bulk. Less

Report

(4 results)
  • 2005 Annual Research Report   Final Research Report Summary
  • 2004 Annual Research Report
  • 2003 Annual Research Report
  • Research Products

    (9 results)

All 2006 2005 2003 Other

All Journal Article (8 results) Publications (1 results)

  • [Journal Article] Stabilization of the γ Phase in Nanoparticles of Fe-Pt Alloys with Low Pt Contents Prepared by Chemical Synthesis Method2006

    • Author(s)
      T.Tadaki, 他3名
    • Journal Title

      Mater.Sci. & Eng.A (in press)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Stabilization of the γ Phase in Nanoparticles of Fe-Pt Alloys with Low Pt Contents Prepared by Chemical Synthesis Method2006

    • Author(s)
      T.Tadaki, et al.
    • Journal Title

      Mater.Sci.& Eng.A (in press)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Stabilization of the γ Phase in Nanoparticles of Fe-Pt Alloys with Low Pt Contents Prepared by Chemical Synthesis Method2006

    • Author(s)
      T.Tadaki 他3名
    • Journal Title

      Mater.Sci.& Eng.A (in press)

    • Related Report
      2005 Annual Research Report
  • [Journal Article] Colorimetric Detection of Fluoride Ion in an Aqueous Solution Using a Thioglucose-capped Gold Nanoparticle2005

    • Author(s)
      S.Watanabe, 他5名
    • Journal Title

      Tetrahedron Letters 46/51

      Pages: 8827-8829

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Colorimetric Detection of Fluoride Ion in an Aqueous Solution Using a Thioglucose-capped Gold Nanoparticle2005

    • Author(s)
      S.Watanabe, et al.
    • Journal Title

      Tetrahedron Letters 46/51

      Pages: 8827-8829

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Colorimetric Detection of Fluoride Ion in an Aqueous Solution Using a Thioglucose-capped Gold Nanoparticle2005

    • Author(s)
      S.Watanabe 他5名
    • Journal Title

      Tetrahedron Letters 46/51

      Pages: 8827-8829

    • Related Report
      2005 Annual Research Report
  • [Journal Article] Au-Cd及びFe-Ni合金ナノ粒子のマルテンサイト変態2003

    • Author(s)
      唯木 次男, 他2名
    • Journal Title

      まてりあ 12.10

      Pages: 725-730

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Martensitic Transformations in Nanoparticles of Au-Cd and Fe-Ni Alloys (in Japanese)2003

    • Author(s)
      T.Tadaki, et al.
    • Journal Title

      MATERIA 12(10)

      Pages: 725-730

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Publications] 唯木 次男 他2名: "Au-Cd及びFe-Ni合金ナノ粒子のマルテンサイト変態"まてりあ. 12・10. 725-730 (2003)

    • Related Report
      2003 Annual Research Report

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Published: 2003-04-01   Modified: 2016-04-21  

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