[18p-A36-1~11] Application of Advanced Ion/Electron Microscopy for Future Nanoscale Materials and Devices

17:30 〜 17:45英語発表

[18p-A36-10] Mapping Dielectric Response of Materials by Time-Resolved Electron Holography

〇Yoh Iwasaki¹, Toshiaki Tanigaki², Keiko Shimada¹, Ken Harada¹, Daisuke Shindo¹ (1.RIKEN, 2.Hitachi, Ltd.)

キーワード：

electron holography、dielectric dispersion、impedance spectroscopy

In characterizing inhomogeneity of dielectric response in materials, AC impedance spectroscopy has been providing invaluable insights into variety of functional systems through careful considerations on equivalent circuits for respective specimens. With a view to obtaining comparable information, we applied a time-resolved version of electron holography to a lithium ion conducting thin film in a transmission electron microscope. A phase distribution was obtained with the specimen under 1 MHz square-wave AC voltage by accumulating 450 ns-long exposures synchronized to the positive periods of the applied voltage. This phase distribution was not identical with a reference potential image of the specimen obtained under a constant positive bias voltage, implying that ionic motion in some parts of the specimen was not able to fully follow the 1 MHz applied field. This method, with its real space imaging capability, may well become a complementary technique for AC impedance spectroscopy.