Soft X-ray Emission Spectrometer(SXES)

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System outline

The newly-developed spectrometer optical system design enables simultaneous measurement of spectra with different energies, without moving the diffraction grating or detector (CCD). With the high energy resolution, chemical state analysis mapping can be performed.

Comparison of SXES, WDS and EDS

Spectra for titanium nitride with various spectrometry methods

For titanium nitride, the peaks of N-Kα and Ti-Ll are overlapped. Even with WDS, and waveform deconvolution using a mathematical method is required. As illustrated in the figure below, there is a high energy resolution with SXES, allowing for TiLl to be observed.

Comparison table

Feature	SXES	EPMA(WDS)	EDS
Resolution	0.3 eV (Fermi edge Al-L)	8 eV (FWHM@Fe-K）	120-130 eV (FWHM@Mn-K）
Chemical bond state analysis	Yes	Yes (mainly light elements)	No
Parallel detection	Yes	No (But multiple spectrometers possible)	Yes
Spectral elements & detector	Diffraction grating＋CCD	Analyzing crystal + Proportional counter	SDD
Detector cooling	Peltier cooling	Not needed	Peltier cooling
Detection limit （reference value with B）	20ppm	100ppm	5000ppm

 

Li-ion battery (LIB) Analysis Example

The example below shows large area maps of LIB samples with different charge states. SXES can map the Li-K peak at both the valence band state (left) and the ground state (middle). A carbon distribution map (right) can also see the function on the LIB that is fully discharged.

Fully-charged, Li-K specimen spectrum

Light element measurement example

Measurements of carbon compounds using SXES

It is possible to measure the differences between diamond, graphite and polymers. The differences can be observed with the additional peaks from π and σ bonding. As mapping takes a spectra from each pixel, additional maps can be generated for peak shifts of 1 eV and shoulder peaks.

Measurements of various nitrogen compounds

For nitrogen as well, the chemical bonding state can be analyzed from the spectrum peak shape. The peak shapes for nitrates and nitride are completely different, and it is even possible to observe the unique peak shape for ammonium salt, which is very beam sensitive.