1999 Fiscal Year Final Research Report Summary
Nanometer-scale Electrical Properties of Ferroelectric Organic Thin Films Investigated by Scanning Probe Microscopy
| Project/Area Number |
09305005
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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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 |
YAMADA Hirofumi Kyoto Univ., Dept. of Electrical Engineering, Asistant Professor, 工学研究科, 助教授 (40283626)
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| Co-Investigator(Kenkyū-buntansha) |
HORIUCHI Toshihisa Kyoto Univ., Dept. of Electrical Engineering, Research Associate, 工学研究科, 助手 (10238785)
TADA Hirokazu Kyoto Univ., Dept. of Electrical Engineering, Lecturer, 工学研究科, 講師 (40216974)
MATSUSHIGE Kazumi Kyoto Univ., Dept. of Electrical Engineering, Professor, 工学研究科, 教授 (80091362)
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| Project Period (FY) |
1997 – 1999
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| Keywords | Ferroelectric Polymers / Scanning Probe Microscopy / Piezoelectric Response Image / PVDF / VDF oligomer / Nanoscale Polarization Domain / Ultrahigh Density Data Storage / Nanoscale Polarization Recording |
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| Research Abstract |
Ultarthin films of copolymers of poly (vinylidene fluorde/trifluoroethylene) on a conduting substrate were prepared by spin-coating method and by the following thermal anealing. High-resolution imaging of the films by atomic force microscopy (AFM) revealed that the films consisted of rod-like grains of which the typical dimensions were 100 nm in width and 100 nm in length. In addition, internal fine structures inside the grains were also found.
Electrical properties of nanometer-scale polarized domains which were formed by applying high electric field using a conductive AFM cantilever were investigated. Furthermore, the dependence of the size of the domains on the poling condition such as voltage and time was also investigated. The results indicated the existence of a persistent polarized layer which was caused by the interaction between the polymer film and the substrate surface.
Local variation in surface potential on the films was mapped by Scanning Maxwell Microscopy. The observed polarity of the potential on the polarlized domains showed that the origin of the potential was not the dipole oriented by the poling but some charges injected or deposited by the tip.
Finally, in the optimum poling condition the polarized domains with a diameter of 30 nm were successfully obtained on the film with a thickness of 30 nm. Since this recording size corresponds to a recording density of 230 Gbit/inィイD12ィエD1, the technique is promising for an ultrahigh density data storage.
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