Indispensable micro-analytical instruments for metal alloy development

State-of-the art scanning transmission electron microscopy  (STEM) is an advanced characterization tool dedicated to analyse sample morphology, structure and chemical composition with the capability of atomic resolution imaging and chemical analysis on the atomic scale.

The new high resolution scanning transmission electron microscope (HR-STEM), equipped with a field emission gun (FEG) and a spherical aberration corrector (Cs), enhances the spatial resolution from 1 nm to less than 0.1 nm, allowing to analyse material structures down to the sub nanoscale. Moreover, this device is equipped with a new generation EDX detector, with a large solid angle, for ultra-fast chemical (elemental) mapping. This accelerates elemental mapping with improved element detection sensitivity, making even atomic EDX mapping possible.

HR-STEM analysis already supported OCAS projects with advanced characterisation of microstructures of different types of steel or metal alloys, both by elemental and crystallographic analysis.

OCAS has direct access to a JEOL ARM200F which is the new probe-lens aberration corrected high resolution STEM which was acquired via the Hercules Foundation by a consortium of KULeuven and JEOL. JEOL ARM200F is an atomic resolution analytical electron microscope, with a spherical aberration (Cs) corrector and cold field emission gun (cold-FEG), providing a STEM-HAADF resolution of 78pm and full analytical capabilities using EDX and EELS. (HAADF: high angle annular dark field, highly sensitive to atomic-number contrast). The new Centurio EDX detector speeds elemental mapping and improves element detection sensitivity without loss of energy resolution. Unique features of this ARM200F instrument:

  • Cold FEG gun with 10-9 mbar vacuum, which provides ultra-fine, high brightness and ultra-stable probe yielding, 0.08 nm resolution in STEM mode
  • Ultra-high resolution, also at low voltage
  • Back-scattered electron detector to image the surface instead of the bulk
  • Newest generation EDX detector Centurio (JEOL) with a large solid angle SDD detector for fast and high spatial resolution chemical mapping. Atomic EDX mapping is possible
  • Gatan Image Filter (GIF) for EELS spectroscopy and filtered imaging (EELS: electron energy loss spectroscopy for chemical and compositional analysis)

Discover the presentation “Micro-analytical instruments: indispensable in the development of steel” by Ann De Vyt, presented at the occasion of the inauguration of the STEM facility.

“To understand the interaction between steel properties and steel making, we need to study the structure of the steel from micrometer level to atomic scale. Several examples can be shown on how routine equipment and high-end instrumentation go hand in hand to help us develop new alloys.”

Hui SHI Maggie, Research Engineer Material Characterisation & Testing department, OCAS