Victor Trillaud (MATEIS), Pierre Alcouffe (IMP), Sylvie Descartes (LaMCoS).
Presentation of the microscope
QUATTRO microscope is the latest environnemental scanning electron microscope from ThermoFisher Scientific. It was installed in CLYM in Dec, 2018. It is equipped with a field electron gun and a large chamber. This device is dedicated to dynamic studies and in situ systems under various environments (H2O, Air, CO2, N2, NO2,...) and excitations (high or low temperatures, mechanical stress,…). Quattro combines high resolution and ability to work in various environments (1.0nm @ 30kV in HV ; 1.4nm @ 30kV in ESEM).
Quattro is equipped with numerous accessories allowing various dynamic modes:
- Peltier Stage (-25 to 60°C), in order to analyze hydrated samples. In parallel, the vapor pressure can be set up to 4700 Pa.
- High Temperature Stages (up to 800°C in vacuum, 1400°C in gaseous mode).
- STEM mode, for the observation of thin samples, in bright or dark field.
- WetSTEM Mode, to study thin samples in controlled pressure or hydrated mode.
- WetSTEM Tomography, to analyze samples in 3D. The sample can be in the dry state or can be liquids (suspensions, emulsions).
- Tensile Stage
- Tribology Stage
- EDS: with a SDD detector (Ultim’Max 100 mm2 from Oxford Instruments), Quattro is well suited to carry out microanalysis experiments in gaseous environnement. In that case, a conical detector can be installed below the column to limit the skirt effect. This brings good spatial resolution during EDS acquisition.
The device is also equipped with numerous detectors:
- SE (ETD) and DBS are BSE detectors, sensitive at low voltages. Their geometries are well suited to filter topographic or Z-contrast signals, while the sample is under vacuum or in a gaseous environment (maximum pressure 200 Pa).
- LVD detector collects the mixed SE+BSE signal, up to 200 Pa in the Low Vacuum mode.
- GSED detector collects the "pure" SE signal in hydrated or auxiliary mode, up to 4700 Pa.
- GAD detector uses SE and BSE signals up to 4700 Pa.
- STEM3+: This detector with 5 concentric ring diodes is used in STEM and WetSTEM to filter bright field, dark field and high angle dark field (HAADF).
- High temperature detector, usable from 5kV with a very good resolution:
- 50nm @ 20kV and 1000°C in vacuum
- 100nm @ 5kV and 1000°C in vacuum
- 70nm @ 15kV and 1000°C in 260Pa H2O
- 250 nm @ 5kV and 1000°C in 260Pa H2O
|Demoistening of a layer on substrate at 575°C, under vacuum (10kV – ETD – scale bar 4 µm)
||Demoistening of a layer on substrate at 950°C, under vacuum (5kV – ETD - scale bar 5 µm)
|Recrystallization of a salt (20kV – GSED - 2°C - 3.5 Torr H2O - scale bar 200 µm)
||Sintering of glass particles at 700°C (30kV – GSED - 0.8Torr H2O – scale bar 10 µm)