JEOL R005 Instrument Details
The R005 contains two sets of asymmetrical dodecapole corrector lens assemblies designed by JEOL. The upper aberration corrector eliminates the opening error of the probe-forming condenser lens system. This allows us to either focus the electron beam to ~1Å in diameter and perform scanning TEM (STEM) at this resolution, or we can generate a larger diameter electron beam that is similar in size to a conventional field-emission instrument but with significantly increased current (several nA within a few Ångstrøms). This is useful for improving the signal-to-noise ratio and/or reducing the acquisition time, and thus drift during mapping.
In scanning mode the images are generated on a computer screen by reading out on-axis (bright field) or off-axis (annular dark-field) detectors that record electron intensities at each point of the scan. Alternatively, electron energy-loss or characteristic X-ray signals can be mapped point-by-point.The lower aberration corrector eliminates the opening error of the main objective lens used for lattice imaging at high magnification with planar illumination.
Images can be recorded on several CCD cameras that are fibre-optically coupled to scintillator coated screens. We can thus improve the point resolution down to >1Å also in this mode and at the same time reduce image delocalisation effects by practically eliminating all transfer gaps up to very high spatial frequencies. As a result of this, the edges of specimens, interfaces and surfaces now appear atomically sharp and can be studied in-situ.
The post column electron energy loss spectrometer (Gatan™ Tridium) provides potential for energy-filtered imaging to map the distribution of certain elements, mostly light elements and transition metals, with ~1nm resolution. This is complemented by the energy-dispersive X-ray spectrometer (JEOL) offering ~2nm resolution and relatively fast elemental mapping of the lateral distribution of heavy elements.