With the use of a variable space grating, JEOL has created a novel wavelength dispersive spectrometer (WDS) that enables the effective and parallel collection of very low energy rays, or “soft” X-rays.
These new Soft X-ray Emission Spectrometers (SXES) have ultra-low energy and low concentration sensitivity, which can detect Li even at low single-digit weight percent concentrations, in addition to high spectral resolution (0.3 eV), which enables the resolution of the Nitrogen Kα and Titanium Lℓ line with a separation of only 1.78 eV.
Its capacity to perform chemical state analysis is another, and perhaps its greatest advantage. The spectrometer distinguishes between bonding and crystal structure in samples that contain the same elements by detecting differences between conduction band and valence band electrons when they emit X-rays.
Differentiating between highly ordered pyrolytic graphite, diamond, and amorphous C—all of which are composed entirely of carbon is one example.
Another version of the Soft X-ray Emission Spectrometer with an extended energy range (SXES-ER) has also been added by JEOL. The spectral range of the SXES-ER is 100 eV to about 2300 eV. This wider range makes it possible to collect heavy elements using the L, M, and N lines in addition to light elements and transition metals.
The SXES is compatible with JEOL W/LaB6/FEG EPMA systems as well as JEOL FE-SEMs.
Li Detection: Peak Shape in Compounds
There is only one K-line found in metallic Li. Additional satellite peaks in Li-compounds may arise based on the valence band's occupancy.
High Energy Resolution Spectral Mapping
For the first time, the Li-K emission can be directly observed, thanks to the SXES. It can even map the various chemical states that arise from varying battery charge levels in a Li-battery. It is possible to map two distinct Li-K emission lines.
The degree of charge in the battery is indicated by the intensity of the lower energy Li-K line, while the amount of metallically bonded Li is indicated by the higher energy Li-K line.
Fast Parallel Detection
The SXES can simultaneously collect a spectrum over a broad energy range, thanks to a high sensitivity X-ray CCD and a recently developed aberration corrected grating system.
Chemical State Analysis
Chemical state analysis using the SXES is similar to that of XPS or EELS. Using the Fermi-edge of the Al-L emission of Al metal, it is shown that the SXES has an energy resolution of 0.3 eV.
Key Features
SXES
- Outstanding detection of light elements (suitable for Li)
- Perfect for light element chemical state analysis, which is essential for battery research
- Excellent sensitivity: a few tens of parts per million B in steel
- Even the second and third order lines have a high P/B ratio and high resolution in the energy range of 50 eV to 210 eV.
- 0.3 eV of extreme spectral resolution, Fermi edge of Al-L
- As there are no moving parts, it is very stable and reproducible.
- As part of an integrated analytical system or operating as an independent detector.
- Using spectral mapping is simple.
SXES-ER
- Outstanding detection of light elements (B-S 1st order)
- First-order K lines (N-S), L lines (Ca-Mo), and M lines (Cd-Bi) can all be detected.
- Analysis of Be-N's trace elements and chemical state
- Fe-L α 5.0 eV FWHM JS200N and Zr-M z 1.2 eV FWHM JS300N have extremely high spectral resolution.
- As there are no moving parts, it is very stable and reproducible.
- As a standalone detector or as a component of an integrated analytical system
- Using spectral mapping is simple.