Benchmarks

Figure 1 illustrates the experimental setup for X-ray absorption spectroscopy (XAS) measurements. Both configurations show X-rays (X線) passing vertically through the sample (試料). A Kapton window (カプトン窓) is used.
(a) Previous setup (2016A): Infrared light (赤外線) is incident from the left.
(b) Current setup (2017A): Infrared light (赤外線) is incident from both the left and the right.

Figure 2 displays the XANES spectra for $\backslash text\{Na\}\_2\backslash text\{WO\}\_4$ . The Y-axis represents Normalized Absorbance (a.u.) and the X-axis represents Energy / keV. The red line represents $\backslash text\{Na\}\_2\backslash text\{WO\}\_4$ at $950^\backslash circ\backslash text\{C\}$ , and the black line represents $\backslash text\{Na\}\_2\backslash text\{WO\}\_4$ after cooling (冷却後). The spectra show the absorption edge around 69.5 keV.

Figure 3 displays the EXAFS oscillations for $\backslash text\{Na\}\_2\backslash text\{WO\}\_4$ . The Y-axis represents $k^3\backslash chi(k)$ (a.u.) and the X-axis represents $k\; /\; \backslash text\{nm\}^\{-1\}$ . The red line represents $\backslash text\{Na\}\_2\backslash text\{WO\}\_4$ at $950^\backslash circ\backslash text\{C\}$ , and the black line represents $\backslash text\{Na\}\_2\backslash text\{WO\}\_4$ after cooling (冷却後). The oscillations show differences between the high-temperature and cooled states, indicating changes in the local structure.