1995 Fiscal Year Final Research Report Summary
DEVELOPMENT OF SCANNING PHONON TRANSMISSION MICROSCOPE (SPTM)
| Project/Area Number |
06555008
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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 |
表面界面物性
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
SAKAI Akira KYOTO UNIVERSITY,DEP.OF ENGINEERING,PROFESSOR, 工学研究科, 教授 (80143543)
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| Co-Investigator(Kenkyū-buntansha) |
MIZUSHIMA Koichi TOSHIBA R&D CENTER,ADVANCED RES.LAB., SUPERVISOR, 基礎研究所, 技監
HASEGAWA Yukio TOHOKU UNIVERSITY,INST.MAT.RES., ASSOC.PROFESSOR, 金属材料研究所, 助教授 (80252493)
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| Project Period (FY) |
1994 – 1995
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| Keywords | Superconducting Tip / Inertia Motion System / Scanning Hall Probe |
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| Research Abstract |
High-frequency (HF) phonons are generated from SNS tunnel junctions. In the scanning phonon transmission microscope (SPTM), one electrode of SNS is replaced by a superconducting tip which moves over the sample keeping in contact with the N-S overlayr on the sample. In this manner, SPTM scans the HF phonon source over the sample and thus studies the local transmission of HF phonons through the sample. The purpose of this research is to develop this SPTM,and following results have been obtained on some technical aspects of SPTM.
1. Fabrication of superconducting tips : Soft superconducting metals have been rarely fabricated into tips because of their difficulty in electropolishing. By employing a two-stage electropolishing, tip fabrication has been successfully made for Nb, Pb, V,Ta, Sn, In, and Re. All these tips have a tip radius of less than 500 nm. Pb and In tips have been made for the first time in this work.
2. Development of the inertia motion system : A low-temperature inertia motion system is indispensable in SPTM for making tip approach to the N-S overlayr. The performance of inertia motion system critically depends on the waveform of the piezo-driving signal. In this work, various waveforms have been tested, includig sawtooth, cycloid, and parabolic waveforms. It is found that the sawtooth waveform cannot make verical translation. Using the cycloid waveform, inertia movement of 90 nm/step has been achieved at liquid helium temperature.
3. Uniformity of the superconducting overlayr : uniformity of the superconducting overlayr can be investigated by Scanning Hall Probe (SHP). TO test the capability of SHP,imaging experiments have been carried out on Bi2223 tapes on their remanent state. It is found that the SHP microscopy clearly images defective and non-superconducting regions embbeded inside the sample.
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