The FEI Quanta 450 FEG of CISUP is a field emission gun – scanning electron microscope (FEG-SEM) used for high-resolution imaging (morphological and compositional) of both conductive and non-conductive specimens at the nanometer-scale resolution (magnification range: from 6 x to 1,000,000 x) and for semi-quantitative X-ray microanalysis. The instrument operates under three imaging modes: high and low vacuum and extended low vacuum modes. The instrument can thus accommodate multiple sample, imaging and analytical requirements for both material and life sciences, allowing investigation of a wide range of traditional and non-traditional samples with or without preparation, including wet samples in their natural state. The coherent high current density (brightness) electron beam delivered by the thermally assisted field emission gun (FEG) enables high imaging resolution down to ~1 nm.
The FEI Quanta 450 FEG operates under three modes:
> High vacuum mode (chamber vacuum pressure < 6 e-4 Pa; nominal 1.0 nm electron beam resolution at 30 kV) used for high-resolution imaging and microanalyses of conductive samples in both secondary electron (SE) and backscattered (BSE) modes. > Low vacuum mode (chamber vacuum pressure 10 – 130 Pa; nominal 1.4 nm electron beam resolution at 30 kV) for high-resolution imaging and microanalyses of non-conductive samples in both secondary electron and backscatter modes. > Extended low vacuum mode ESEM (chamber vacuum pressure 10 – 4000 Pa; nominal 1.4 nm electron beam resolution at 30 kV) for charge-free imaging and microanalysis of non-conductive and/or hydrated specimens.
The FEI Quanta 450 FEG is equipped with:
> Bruker’s QUANTAX XFlash Detector 6|10 for microanalyses and X-ray compositional mapping. > Bruker’s QUANTAX EBSD/EDS analysis system for phase identification and textural mapping. > Heating (Tmax = 1000 °C) and cooling (Trange = -25°C / +60 °C) stages for in situ heating/cooling experiments.
Recent applications include the nanocharacterization of:
> Characterize conductive and non-conductive samples with SE and BSE imaging possible in every mode of operation. > Minimize the amount of sample preparation, low vacuum and ESEM capability enables charge-free imaging and analysis of non-conductive and/or hydrated specimens. > Increase analytical capabilities by enabling EDS and EBSD analysis on conductive and non-conductive samples in high and low vacuum. > Stable high current FEG (up to 200 nA) enables fast, accurate analysis. > Perform dynamic in situ analysis of diverse samples in their natural state above or below ambient temperatures from – 25 °C to 1000 °C with specialized in situ stages. > Enable surface imaging with optional beam deceleration mode to get surface and compositional information from conductive samples.
The FEI QUANTA 450 laboratory is equipped with a high vacuum sputter and C-thread coater Leica EM ACE600 for precise coating of samples for subsequent examination within the electron microscope. Two angled sources are configured. One for metal sputtering (Au and Pt and targets available) and one for C-thread evaporation.
An automated stage rotation is integrated for best distribution of the coating. An integrated quartz crystal measurement accurately determines the layer thickness. Tilt and height can be set manually. Any material can be processed as long as it is not sensitive to vacuum, argon plasma or the heat generated during carbon coating.
The vacuum system creates an ultimate vacuum ≤ 2×10-6 mbar enabling even distribution of the coat even in porous samples.