Engineering

Environmental Scanning Electron Microscope

Among the analytical capabilities available at Southern Research Institute is an FEI XL30 Environmental Scanning Electron Microscope (ESEM) equipped with both secondary and backscattered electron detectors, and an EDAX Phoenix Energy Dispersive Spectrometer (EDS). The ESEM is a valuable tool in providing analysis such as the determination of failure mode, analysis of material defects or contaminants, and characterization of microstructures. Versatile features of the system include:

A 2000x secondary electron image of a void found on the fracture surface of a powder metallurgy rhenium tensile sample 2000x secondary electron image of a void found on the fracture surface of a powder metallurgy rhenium tensile sample. Note the features at the grain boundary triple points and along the grain boundaries.

  • Variable vacuum modes for analysis of conductive, non-conductive, and high vacuum incompatible samples
  • Large chamber and stage configuration with five axis specimen positioning controls
  • Enhanced image analysis and manipulation including:
    • Calibrated size and distance measurements including height
    • Annotation overlays
    • Multiple image montages
    • Stereo pair images
    • X-ray maps of multiple elements

A 2000x secondary electron image of a void found on the fracture surface of a powder metallurgy rhenium tensile sample EDS detected the presence of hafnium, oxygen, carbon, and calcium at the grain boundary triple points and along the grain boundaries.

The XL30 is capable of 100,000x and 3.5 nm resolution at 30kV and 20,000x and 20nm resolution at 1kV. At the lower beam potentials, excellent topographic details can be obtained, while the higher potentials yield optimum resolution and efficient EDS analysis.

The EDS system can be used to identify the major elements present in a sample in concentrations greater than about 1 wt% and can detect elements as low as carbon on the periodic table.

The microscope is also equipped with a high temperature heating stage for continuous in situ imaging of live dynamic heating experiments up to 1000°C in an inert, oxidizing, or reducing atmosphere.

The combination of advanced, high-resolution imaging, elemental analysis, image manipulation, and hot stage capabilities makes this a very powerful research tool.

Specifications of XL-30 ESEM
  • Source — Optimized tungsten gun with low kV booster, 0.2 – 30 kV accelerating potential with automatic focus compensation
  • Resolution — 3.5 nm at 30 kV, 20 nm at 1 kV
  • Detectors — SE, BSE, EDS, CCD camera
  • Images — Max 4k x 3k 8 bit grayscale saved as uncompressed image files
  • Stage
  • — 100 mm X-Y travel, 1-60 mm Z travel, 360° rotation, - 5° to 70° tilt, all five axes under computer control
  • Hot Stage
  • — Max 1000°C, 1°/min to 300°/min (5°/sec), ± 25°C
  • Software
  • — Windows NT controls beam and stage, XL Docu image database management software, on-screen x-y measurements can be transferred to Excel datasheet