Unlike conventional scanning electron microscopes, the Thermo Scientific “Quattro S” allows samples to be examined not only under high vacuum conditions: imaging is also possible in a controlled atmosphere at pressures of up to 40 mbar and with sample temperatures ranging from -20 °C to 1400 °C. This enables, for example, the investigation of catalyst particles in an environment close to their working conditions “in operando.” Therefore, the instrument is referred to as an “Environmental and In-Situ Scanning Electron Microscope” (EiSEM), or from English as an “Environmental Scanning Electron Microscope” (ESEM).

In addition to a good spatial resolution of 1 nm in conventional high vacuum mode, the instrument features a variety of other capabilities:

• STEM Detector (Scanning Transmission Electron Microscopy) This detector uses electrons transmitted through a very thin sample for imaging, enabling visualization of the internal structure of the sample with excellent spatial resolution down to 0.8 nm.
• EDX Detector (Energy-Dispersive X-ray Spectroscopy)  Like all our electron microscopes, the Quattro S is equipped with an EDX detector that captures X-ray radiation emitted by the sample, allowing qualitative and quantitative determination of the sample composition.
• EBSD Detector (Electron Backscatter Diffraction) "Lumis"  Acquisition of discrete patterns of forward-scattered electrons allows differentiation of crystallographic phases and their orientation within the sample.
• EBAC Detector (Electron Beam Absorbed Current) This detector measures the current flowing through the sample and is particularly suitable for the examination of conductive samples at high temperatures.
• GIS (Gas Injection System) Via a needle that can be positioned within a few micrometers of the sample surface, the sample can be exposed to reactive gases, including carbon monoxide and ammonia.
• Mass Spectrometer  A mass spectrometer connected to the microscope’s vacuum system can detect and characterize gaseous species—for example, those generated during the thermal decomposition of a sample—based on their mass.

With these options, the Quattro S is a versatile electron microscope, enabling the investigation of a wide variety of samples under a range of environmental conditions.