New microscope for measuring the distribution of nonlinear dielectric properties

Electron. Comm. Jpn. Pt. II

Okada

Ohara

et al. 2005

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SUMMARYWe have developed a high-resolution scanning nonlinear dielectric microscope that can provide imaging with subnanometer resolution of domain structure in the polarization of ferroelectrics. Using this microscope, we were able to image several types of domain structures in ferroelectric materials. Moreover, because nonlinear dielectric responses of any order can be used for imaging, and because it is simple to vary the order used, our nonlinear dielectric constant microscope has higher-order modes of operation, whose use improves the resolution of the microscope. In addition, the configuration of our microscope allows us to image the polarization in the direction parallel to the sample surface by suitably rotating the direction of the applied electric fields. This imaging is possible because the microscope yields information about the full third-order nonlinear dielectric constant tensor. In the course of exploring ways to apply this microscope technology to next-generation ultrahigh-density ferroelectric data storage, we have recently shown data storage at densities of 1.5 Tbit/in 2 , which is the world's highest storage density in a rewriteable storage medium.

Section: Introductionmentioning

confidence: 97%

Scanning nonlinear dielectric microscopy and its use in next-generation ultrahigh-density ferroelectric data storage

Electron. Comm. Jpn. Pt. II

Okada

Ohara

et al. 2005

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Atomic Dipole Moment Distribution of Si Atoms on aSi(111)−(7×7)Surface Studied Using Noncontact Scanning Nonlinear Dielectric Microscopy

Hirose

2007

Phys. Rev. Lett.

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A local atomic electric dipole moment distribution of Si atoms on Si(111)-(7 x 7) surface is clearly resolved by using a new technique called noncontact scanning nonlinear dielectric microscopy. The dc-bias voltage dependence of the atomic dipole moment on the Si(111)-(7 x 7) surface is measured. At the weak applied voltage of -0.5 V, a positive dipole moment is detected on the Si adatom sites, whereas a negative dipole moment is observed at the interstitial sites of inter Si adatoms. Moreover, the quantitative dependence of the surface dipole moment as a function of the applied dc voltage is also revealed at a fixed point above the sample surface. This is the first successful demonstration of direct atomic dipole moment observation achieved in the field of capacitance measurement.

Scanning nonlinear dielectric microscopy with nanometer resolution

ISAF 2000. Proceedings of the 2000 12th IEEE International Symposium on Applications of Ferroelectrics (IEEE Cat. No.00CH37076)

Kazuta

Matsuura

et al.

A very high-resolution scanning nonlinear dielectric microscope with nanometer resolution was developed for the observation of ferroelectric polarization. We demonstrate that the resolution of the microscope is of a nanometer order by measurement of the cc domain wall of a BaTi03 single crystal and of the domains in PZT and SBT thin films. Especially in a film measurement, the resolution was sub-nanometer order. Next, we also demonstrate that the resolution of SNDM is higher than that of a conventional piezo-response imaging. Finally, to check the performance of the SNDM system as a ferroelectric recording system, we conducted a fundamental study on the writing of domain inversion dot in PZT thin film and succeeded to have a very small domain dots with the size of 2 5 m .