Fig. 4: Temperature dependence of (1/4 1/4 L) Bragg peak with σ photon polarization.
a Cuts of the scattering intensity through the SDW peak at L = 1.93 and 852 eV with incident σ photon polarization at various temperatures. The peak is broader with σ polarization than with π polarization (Fig. 1b) and exhibits a non-monotonic temperature dependence. b The temperature dependence of the (1/4 1/4 1.93) peak amplitude, \({I}_{s}\), with σ and π incident polarization. The peak emerges at 200 K, but peaks at 130 K with σ polarization. c The ratio of the scattering intensity from σ and π incident light, \({I}_{\sigma }/{I}_{\pi }\), which increases monotonically with increasing temperature. d The FWHM of the (1/4 1/4) peak with σ and π incident light. As described in supplementary section VII, IS with σ incident light is fit to two peaks (broad and narrow). The narrow peak has FWHM comparable to the IS with \(\pi\) incident light and is evident at 20 K in a) but diminished above 100 K. We attribute the narrow peak to an artifact of a few percent contribution of \(\pi\) incident light in the nominal σ polarized beam. The FWHM of the remaining broad peak is shown in d).
