Transmission EELS of oxide superconductors with a cold field emission TEM

Abstract

Electron energy loss spectrometry (EELS) with a cold field emission gun (cFEG) transmission electron microscope (TEM) is implemented to analyze the evolution of the electronic structure and dielectric function of oxide superconductors. The O-K core loss spectra of p-type doped oxide superconductors are analyzed in terms of holes formation on oxygen sites, while low loss spectra are analyzed for free carrier plasmas, other spectral excitations, and their crystallographic confinement. It is illustrated that the transmission EELS with a cFEG TEM very much complement soft X-ray absorption spectroscopy and optical spectroscopy, with the added advantages of high spatial resolution (approximately 1-100 nm), and is compatible with other analytical, diffraction, and imaging techniques, which are readily available in a cFEG TEM.

Site‐specific angular dependent determination of inelastic mean free path of 300 keV electrons in GaN nanorods

“…1,2 With the advancement of electron spectroscopy, the transmission electron microscope (TEM) has become an indis-pensable tool to characterise electronic structure, optical excitations, plasmonic excitation and dielectric properties along with their geometric structure. [3][4][5][6][7][8][9][10][11][12][13] IMFP of electrons is defined as the average distance travelled between two successive inelastic collisions by an electron moving with a particular energy in a given material. Hence to analyse EELS data in TEM operating at a typical energy of 100-300 keV, knowledge of IMFP at those high energies is required.…”

“…IMFP is also related to several other important parameters of materials, for example, effective attenuation length, mean escape depth and information depths etc 1,2 . With the advancement of electron spectroscopy, the transmission electron microscope (TEM) has become an indispensable tool to characterise electronic structure, optical excitations, plasmonic excitation and dielectric properties along with their geometric structure 3–13 . IMFP of electrons is defined as the average distance travelled between two successive inelastic collisions by an electron moving with a particular energy in a given material.…”