| Project/Area Number |
61460029
|
|---|
| Research Category |
Grant-in-Aid for General Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
固体物性
|
|---|
| Research Institution | The University of Tokyo |
|---|
Principal Investigator |
TAKEUCHI Shin Inst. Solid State Phys., Univ. Tokyo, Professor, 物性研究所, 教授 (60013512)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
SUZUKI Kunio Inst. Solid State Phys., Univ. Tokyo, Research Associate, 物性研究所, 助手 (50107439)
KIMURA Kaoru Inst. Solid State Phys., Univ. Tokyo, Research Associate, 物性研究所, 助手 (30169924)
YASUOKA Hiroshi Inst. Solid State Phys., Univ. Tokyo, Professor, 物性研究所, 教授 (50026027)
|
|---|
| Project Period (FY) |
1986 – 1987
|
| Project Status |
Completed (Fiscal Year 1988)
|
| Budget Amount *help |
¥7,800,000 (Direct Cost: ¥7,800,000)
Fiscal Year 1987: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1986: ¥6,900,000 (Direct Cost: ¥6,900,000)
|
|---|
| Keywords | quasicrystal / single-phase quasicrystal / multi-component alloy / electrical resistivity / resistivity anomaly / 磁性 / 超急冷法 / ペンローズ格子 / 電子線回折 / Al合金 / 局在電子 |
|---|
| Research Abstract |
The purpose of the research in to produce high-quality quasicrystalline alloys and to investigate physical properties characteristic of quasicrystals.
(1) Production of high-quality quasicrystals (a) Al-Mn based alloys: We have first determined the composition range of Al-Mn bianry alloys in which single-quasicrystalline phase is produced by melt-quenching. Then we have clarified the composition region of the quasicrystalline phase for ternary Al-Mn-Si system and further tried to improve the quality by subsitution of 14 transition elements for Mn. As a result, we have succeed in obtaining excellent-quality and very stable quasicrystalline phase for some quaternary systems such as Al-Ru-Mn-Si. (b) Simple Metal systems: We have also determined the composition region of single-quasicrystalline phase for the ternary Mg-Al-Zn systems. We have also produced large grain quasicrystals of Al-Li-Cu alloy.
(2) Electrical resistivities of quasicrystals We have measured the electrical resistivity and the magnetic susceptivility for the produced single-phase quasicrystalline alloys. the resistivities of Al-Mn systems are as high as the order of 1 m cm and have a negative temperature coefficent. Below about 50K, we observed an anomalous resistivity increase, the amount of which has been found to be closely related to the localized magnetic moment of Mn. The magneto-resistance is negative in the -logT-dependent region, in contradictory with the Kondo effect. This resisitivity anomaly has been tentatively interpreted by the critical state of electrons in the quasicrystalline state. Systematic measurements for simple-metal quasicrystals such as Mg-Al-Zn and Al-Li-Cu are in progress.
|
