Recent Progress in Far-Field Optical Metalenses

Electromagnetic interference shielding materials: recent progress, structure design, and future perspective

Journal of Materials Chemistry C ◽

10.1039/d1tc04702g ◽

2022 ◽

Author(s):

Xiao-Yun Wang ◽

Si-Yuan Liao ◽

Yan-Jun Wan ◽

Peng-Li Zhu ◽

You-Gen Hu ◽

...

Keyword(s):

Electromagnetic Interference ◽

Recent Progress ◽

Near Field ◽

Structure Design ◽

Measurement Methods ◽

Future Perspective ◽

Far Field ◽

Future Perspectives ◽

Electromagnetic Interference Shielding ◽

Novel Structure

Novel structure design and shielding mechanism of various shielding materials are critically reviewed. Measurement methods of far-field and near-field shielding are presented. Challenges and future perspectives for shielding materials are discussed.

Download Full-text

Electron-Mirror Microscopic Aspects of Ferroelectric Domains of BaTiO3 And Ca2Sr (C2H5CO2)6

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100069387 ◽

1970 ◽

Vol 28 ◽

pp. 478-479

Author(s):

Teruo Someya ◽

Jinzo Kobayashi

Keyword(s):

Surface Layer ◽

Electric Fields ◽

Quantitative Study ◽

Recent Progress ◽

Ferroelectric Domain ◽

Resolving Power ◽

Surface Pattern ◽

Crystal Surfaces ◽

One Dimensional ◽

Ferroelectric Domains

Recent progress in the electron-mirror microscopy (EMM), e.g., an improvement of its resolving power together with an increase of the magnification makes it useful for investigating the ferroelectric domain physics. English has recently observed the domain texture in the surface layer of BaTiO3. The present authors ) have developed a theory by which one can evaluate small one-dimensional electric fields and/or topographic step heights in the crystal surfaces from their EMM pictures. This theory was applied to a quantitative study of the surface pattern of BaTiO3).

Download Full-text

Possible applications of fraunhofer holography in high resolution electron microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100108258 ◽

1978 ◽

Vol 36 (1) ◽

pp. 222-223 ◽

Cited By ~ 1

Author(s):

N. Bonnet ◽

M. Troyon ◽

P. Gallion

Keyword(s):

Electron Microscopy ◽

High Resolution ◽

Transfer Function ◽

Radiation Damage ◽

High Resolution Electron Microscopy ◽

Far Field ◽

Field Region ◽

Crystalline Materials ◽

Resolution Electron ◽

The Ideal

Two main problems in high resolution electron microscopy are first, the existence of gaps in the transfer function, and then the difficulty to find complex amplitude of the diffracted wawe from registered intensity. The solution of this second problem is in most cases only intended by the realization of several micrographs in different conditions (defocusing distance, illuminating angle, complementary objective apertures…) which can lead to severe problems of contamination or radiation damage for certain specimens.Fraunhofer holography can in principle solve both problems stated above (1,2). The microscope objective is strongly defocused (far-field region) so that the two diffracted beams do not interfere. The ideal transfer function after reconstruction is then unity and the twin image do not overlap on the reconstructed one.We show some applications of the method and results of preliminary tests.Possible application to the study of cavitiesSmall voids (or gas-filled bubbles) created by irradiation in crystalline materials can be observed near the Scherzer focus, but it is then difficult to extract other informations than the approximated size.

Download Full-text

The Nature of Oxide Surfaces: Topographic and Electronic Structure

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100150666 ◽

1993 ◽

Vol 51 ◽

pp. 966-967

Author(s):

Dawn A. Bonnell ◽

Yong Liang

Keyword(s):

Transition Metal Oxides ◽

Electronic Structures ◽

Recent Progress ◽

Spatial Localization ◽

Level Of Detail ◽

Scanning Tunneling ◽

Oxide Surfaces ◽

Tunneling Microscopy ◽

Considerable Effort ◽

Complete Understanding

Recent progress in the application of scanning tunneling microscopy (STM) and tunneling spectroscopy (STS) to oxide surfaces has allowed issues of image formation mechanism and spatial resolution limitations to be addressed. As the STM analyses of oxide surfaces continues, it is becoming clear that the geometric and electronic structures of these surfaces are intrinsically complex. Since STM requires conductivity, the oxides in question are transition metal oxides that accommodate aliovalent dopants or nonstoichiometry to produce mobile carriers. To date, considerable effort has been directed toward probing the structures and reactivities of ZnO polar and nonpolar surfaces, TiO2 (110) and (001) surfaces and the SrTiO3 (001) surface, with a view towards integrating these results with the vast amount of previous surface analysis (LEED and photoemission) to build a more complete understanding of these surfaces. However, the spatial localization of the STM/STS provides a level of detail that leads to conclusions somewhat different from those made earlier.

Download Full-text