| Budget Amount *help |
¥12,700,000 (Direct Cost: ¥12,700,000)
Fiscal Year 1999: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1998: ¥5,700,000 (Direct Cost: ¥5,700,000)
Fiscal Year 1997: ¥6,100,000 (Direct Cost: ¥6,100,000)
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| Research Abstract |
Recently, we have proposed and developed a new, purely electrical method for imaging the state of remanent polarization of ferroelectric materials, which involves the measurement of point-to-point variation of the nonlinear dielectric constant of a specimen, and is termed "scanning nonlinear dielectric microscopy (SNDM)". However, greater demand for the observation of very small domains (or dipoles) of nanometer size has arisen amongst researchers of ferroelectric materials to, for example, investigate domain wall structures or clarify minimum domain sizes.
To achieve higher resolution of the nanometer order, a probe contact sensing mechanism for detecting the exact contact point of the probe needle with the surface of specimen were developed. By combining the contact sensing mechanism and a new lumped constant resonator probe with a very tin pointed end needle, we have succeeded in developing a SNDM system with nanometer resolution.
Next, a theory for scanning nonlinear dielectric microscopy (SNDM) and its application to the quantitative evaluation of the linear and nonlinear dielectric constants of dielectric materials were also developed. A general theorem for the capacitance variation under an applied electric field is derived and then, it was proved that the sensitivity of the SNDM probe does not change, even if a tip with a smaller radius is selected to obtain a finer resolution. Using the theoretical results and the data taken by SNDM, the quantitative linear and nonlinear dielectric properties of several dielectric materials were successfully determined. From the calculation of a one-dimensional image of a 180°c-c domain boundary, it is demonstrated that the SNDM has an atomic scale resolution. The polarities of piezoelectric thin films on piezoelectric substrates were also determined.
Finally, we succeeded in the basic experiment on ferroelectric recording system with a micron-meter order ferroelectric bits.
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