The University of Nantes’ scientists have created a new technique to detect and measure grain boundary separations by utilizing a wavelength dispersive X-ray spectroscopy (WDS).
Carl Zeiss’ MERLIN Field Emission Scanning Electron Microscope, which features an Oxford WDS spectrometer, was used to develop this technique. An experiment was conducted at the Laboratoire de Génie des Matériaux et Procédés Associés Polytech´ Nantes (LGMPA). During the experiment, the electron microscope was operated by applying a high-probe current of 400 nA. The high-probe current enabled sufficient signal excitation.
The GEMINI II column, which is embedded in the MERLIN instrument, features a double condenser lens. The lens significantly reduced the beam diameter to deliver high-spatial resolution of the wavelength dispersive X-ray spectroscopy analysis.
Interfacial separations can cause significant changes in materials properties such as loss in ductility of copper, nickel and iron alloys. Generally, the classification of top surface layers is done with the Electron Probe Micro Analysis or with the Auger Electron Spectroscopy. Both the techniques require high-vacuum conditions or offer limited spatial resolution. The LGMPA technique helps in overcoming all these problems.