School of GeoSciences

School of GeoSciences

SEM

Instrument Specification

The SEM facility is acquiring a new Carl Zeiss SIGMA HD VP Field Emission SEM with Oxford AZtec ED X-ray analysis and Electron Backscatter Diffraction (EBSD) systems.

The SEM

  • Electron Source: Schottky thermal field emitter
  • Accelerating voltage range: 0.02 to 30 kV
  • Current range: 12 pA to 100 nA
  • Secondary Electron imaging: the SIGMA has In-lens, Everhart-Thornley and Variable pressure Secondary electron detectors for the imaging of micro and nano surface features of a wide variety of samples.
  • Resolution: 1.9nm at 1 kV, 1nm at 15 kV.
  • Backscatter Electron imaging: 4 quadrant solid state angle selective backscatter (AsB) detector for imaging compositional variation within samples.
  • Cathodoluminescence: a Deben Centaurus sensitive CL detector with a wide range (185nm to 850nm) scintillator for imaging luminescent materials.
  • The Oxford AZtecEnergy Energy dispersive X-ray analysis system enables qualitative and quantitative analysis of samples and the rapid acquisition of element and phase maps . The 80mm˛ silicon-drift energy dispersive X-ray detector can detect elements Beryllium (Be) to Californium (Cf) .
  • The Oxford AztecHKL EBSD system enables the determination of crystallographic orientation data of suitably prepared samples with high spatial resolution. EBSD analysis can also be combined with simultaneous ED analysis.
  • Large sample chamber that can accommodate specimens up to 250 mm diameter and 45 mm tall.
  • Variable pressure range: 2-133 Pa, allowing the analysis and imaging of insulators, hydrated samples or uncoated specimens without charging artifacts.
  • Stage: 130*130mm eucentric stage with motorised control of X, Y, Z, rotate and tilt (-3° to 70°).
  • Images: All images may be stored using a high resolution digital frame store. Maximum image size: 12288 x 9216 pixels
  • Operating System: All microscope and analysis systems are operated via Windows 7

The Facility also has the necessary support equipment:

  • Sample preparation including impregnation, cutting, grinding and polishing equipment.
  • Carbon and Gold coating.
  • Reflected and transmitted light microscopes with photographic facilities for specimen documentation.
  • Optical cathodoluminescence microscope.
  • Black & White photographic developing and printing facilities.
  • Access to the Electron Microprobe Facility for quantitative major and minor element (0.01 wt%) analysis using either energy dispersive analysis or wavelength dispersive analysis.
  • Access to the Ion Microprobe Facility for isotopic and trace element (ppm) analysis.