2005 Fiscal Year Final Research Report Summary
Nanowire Filled Nanotubes
| Project/Area Number |
16310093
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Nanomaterials/Nanobioscience
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| Research Institution | National Institute for Materials Science |
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Principal Investigator |
GOLBERG Dmitori National Institute for Materials Science, Advanced Materials Lab, Associate Director, 物質研究所, アソシエートディレクター (80354405)
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| Co-Investigator(Kenkyū-buntansha) |
BANDO Yoshio National Institute for Materials Science, Advanced Materials Lab, Fellow, 物質研究所, フェロー (10344433)
MITOME Masanori National Institute for Materials Science, Advanced Materials Lab, Senior Researcher, 物質研究所, 主任研究員 (50354410)
TANG Chengchun National Institute for Materials Science, Advanced Materials Lab, Senior Researcher, 物質研究所, 主任研究員 (10370298)
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| Project Period (FY) |
2004 – 2005
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| Keywords | nanotubes / metals / inorganic materials / electron microscopy / CVD / filling / nanowires |
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| Research Abstract |
Carbon nanotubes were filled with Fe-Co soft ferromagnetic alloys using pyrolysis technique and with Fe-Ni Invar and/or Permalloy alloys, and pure Fe, Co and Ni metals, using chemical vapor deposition (CVD). Drastic increase in coercivity of Fe-Co nanowires encapsulated into C nanotubes (up to 〜900 Oe) was documented, as compared to soft magnetic behavior of Fe-Co bulk alloys during SQUID measurements. Notable chemical modulations were observed in Fe-Ni alloys, embedded in C nanotubes. They associate with the appearance of unusual fcc long period, a=5.43 A, structures in Fe-Ni nanowires. Liquid Ga columns were packed into C nanotubes during high-temperature chemical synthesis using an induction furnace. During atomic force microscopy (AFM), it was found, that electrical conductivity through empty nanotube regions is diffusive with resistance per unit length of 〜25 kOm/μm, whereas Ga-filled segments of the nanotube show striking metallic behavior with resistance as low as 〜0.35 kOm/μm.
… More
No noticeable Schottky barrier exists between nanotube carbon shells and inner Ga filling. The research gas been extended through C and BN nanotube encapsulation with a wide range of functional inorganic materials, namely MgO, MgO_2, SiC, Ga_2O_3. Being encapsulated with a famous oxygen-release compound, a peroxide MgO_2, a Boron Nitride nanotube would serve as a nanoscale oxygen generator. Pure molecular oxygen outflows from the open tube ends, as unstable MgO_2 transforms into stable MgO during moderate heating inside TEM. The electrical response of practically important nanocables made of a SiC semiconductor insulated by pure BN tubular shells was analyzed by AFM. The material would perfectly serve as a field-effect transistor. Novel inorganic nanotubes made of silica were prepared and filled with liquid In. Liquid In mass ultrafast transport inside nanotubes due to nanotube charging under an electron beam followed by electromigration was achieved. World-first high-yield synthesis of 100% pure BN nanotubes (1 g/day) was achieved. The novel way to functionalize these nanotubes and making first nanocomposite polymer films out of them discovered. The composite films displayed superb thermal and mechanical properties as composed to those without BN tube loading. Numerous metal and ceramic filled BN, C and SiO_2 nanotubes were fabricated. Functional properties of such tubes were exploited. First time tuning of BN nanotube band gap via Flourine doping was performed. The electrical calibration of a Ga-filled C nanotube thermometer based on 2-probe tube resistivity measurements was carried out. An original electrical nanoswitch made of such nanotube was created. Unknown Fe-based long-period crystal lattices were discovered inside C nanotubes due to confinement effects. Magnetic coercivity of Fe-Co alloy nanowires encapsulated inside C nanotubes was found to 100 times exceed that of a bulky alloy of the same composition. Mass transport of liquid In clusters and liquid droplets was achieved through external and internal Silica nanotube surfaces. The world-first electrical probing of filled BN nanotubes was performed inside a high-resolution transmission electron microscope. Less
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