Four-dimensional electron microscopy.

نویسنده

  • Ahmed H Zewail
چکیده

The discovery of the electron over a century ago and the realization of its dual character have given birth to one of the two most powerful imaging instruments: the electron microscope. The electron microscope's ability to resolve three-dimensional (3D) structures on the atomic scale is continuing to affect different fields, including materials science and biology. In this Review, we highlight recent developments and inventions made by introducing the fourth dimension of time in electron microscopy. Today, ultrafast electron microscopy (4D UEM) enables a resolution that is 10 orders of magnitude better than that of conventional microscopes, which are limited by the video-camera rate of recording. After presenting the central concept involved, that of single-electron stroboscopic imaging, we discuss prototypical applications, which include the visualization of complex structures when unfolding on different length and time scales. The developed UEM variant techniques are several, and here we illucidate convergent-beam and near-field imaging, as well as tomography and scanning-pulse microscopy. We conclude with current explorations in imaging of nanomaterials and biostructures and an outlook on possible future directions in space-time, 4D electron microscopy.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Recording and Using 4D-STEM Datasets in Materials Science

Traditional scanning transmission electron microscopy (STEM) detectors are monolithic and integrate a subset of the transmitted electron beam signal scattered from each electron probe position, shown schematically in Figure 1. These convergent beam electron diffraction patterns (CBED) are extremely rich in information, containing localized information on sample structure [1], composition [2], p...

متن کامل

Three Dimensional Culturing of Human Jaw Osteoblasts in PLLA/HA Scaffold

Background & Aims: Tissue engineering using somatic cells and synthetic extracellular matrix (scaffold) represents a new approach for regeneration of mineralized tissue and bone. This study was carried out to investigate the ability of a PLLA/HA scaffold to culture osteoblast cells in a three dimensional milieu. Method: Three bony samples were taken from extraction sites during surgical extract...

متن کامل

Ultrafast core-loss spectroscopy in four-dimensional electron microscopy

We demonstrate ultrafast core-electron energy-loss spectroscopy in four-dimensional electron microscopy as an element-specific probe of nanoscale dynamics. We apply it to the study of photoexcited graphite with femtosecond and nanosecond resolutions. The transient core-loss spectra, in combination with ab initio molecular dynamics simulations, reveal the elongation of the carbon-carbon bonds, e...

متن کامل

سنتز گرافن سه بعدی و بهینه‌سازی مورفولوژی آن

Due to electrical properties (high electron mobility) and electrochemical characteristics (high electron transport rate), graphene-based  materials have been widely applied for various scientific fields. However, due to their two-dimensional  structures, these materials have low active sites for reaction. Therefore, changing from two-dimensional sheets dimensional to the three-dimensi...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • Science

دوره 328 5975  شماره 

صفحات  -

تاریخ انتشار 2010