Installation1
Installation1: Electron yield
| Total Electron Yield (TEY) | total electron emission current, energies of optical transitions and qualitative relation with surface sensitivity of optical absorption coefficient together with PEY, EAY, OLY and XFY providing data entry for optical spectroscopy and local structure analysis as in NEXAFS, EXAFS |
| Partial Electron Yield (PEY) | TEY in a selected electron kinetic energy band, surface to volume ratio tunability |
| Electron yield resolved in kinetic energy and momentum | providing entry data for angle integrated and resolved UPS and XPS spectroscopy and related microscopic information including binding energies, energy bands and photoemission cross sections |
| Electron Auger Yield (EAY) | electron emission distribution in kinetic energy of a selected Auger line, providing entry data for Auger Electron Spectroscopy (AES) and surface sensitive evaluation of absorption coefficient of a selected chemical species together with TEY, PEY, UPS, XPS providing tools for surface analysis of materials |
How to measure:
| Total Electron Yield (TEY) | The emission current (drain current) is measured in the usual set up grounding the sample through a picoammeter with highest sensitivity of the order of tenths of fA. Sample biasing (positive, negative) is available. |
|
Partial Electron Yield (PEY) |
Partial Electron Yield can be obtained by selecting using electron analyzers a kinetic energy band. Two hemispherical electron analyzers of mean radius 135 mm (Scienta R3000 – BACH) and 60 mm (home made – BEAR) are available for kinetic energy and momentum resolved measurements of emitted electrons as produced by photoemission and Auger processes and of use in related spectroscopic analysis. |
Hemispherical Electron Analyzers:
| Mean radius r (mm) | Kinetic Energy (eV) | Pass Energy Ep (eV) |
Energy Resolution |
Angular resolution (deg) | |
|
BACH (Scienta R3000) |
135 | 1-2000 |
2,5,10,20, 50,100,200 |
~0.1-1% Ep (slit×Ep/2×r) |
±0.1 |
| BEAR (custom) | 60 | 0-1000 | 1-100 |
~1% Ep |
±1 |