Figure 1

(Color online) The scattering diagram used in the experiment, the superconducting transition, and the raw data acquired for the (1, 0, 1) reflection. Panel (a) shows the scattering diagram where $Q$ is positioned for the (1, 0, 1) reflection. $P\parallel Q$ and $P\perp Q$ are in the scattering plane and are two of the polarization states used. The third state is $P\parallel z$, where $z$ is perpendicular to the scattering plane. (b) shows the superconducting transition obtained by measuring the polarization transmitted through the crystal in zero applied field. The transition is very sharp for an underdoped crystal of the size used. (c) shows a polarized measurement made in the $P\parallel Q$ arrangement where the red squares show the SF magnetic scattering and the blue points are the NSF nonmagnetic scattering normalized to the SF scattering at room temperature. The distinct jump in the SF data below 230 K shows the magnetic transition. The errors are from counting statistics and multiple runs were averaged to improve the counting errorsReuse & Permissions

Figure 2

(Color online) Measurements for the three polarization configurations on the (1, 0, 1) reflection and for the $P\parallel Q$ configuration on the (2, 0, 1) reflection. The fit for the (1, 0, 1) reflection shown in panels (a), (c), and (d) by the red lines is given by $T<T_m,I=BG+{\left[\left(T_m-T\right)/T_m\right]}^{2\beta }$, $T>T_m$, $I=BG$, and $BG=A+BT$. The best fit is for $T_m=235\pm 15\text{K}$ and $2\beta =0.37\pm 0.12$ where $BG$ is a linear background given by the blue line. $BG$ is obtained by dividing the NSF intensity by the temperature dependence of the flipping ratio, $R\left(T\right)$. $R\left(T\right)$ is found by a fit in panel (b) of the ratio NSF/SF of the Bragg peak (2, 0, 1) as $R\left(T\right)=R\left(300\text{K}\right)\left\{1+0.02\left(1-T/300\right)\right\}$.Reuse & Permissions

Figure 3

(Color online) Measurements for two polarization configurations on the (1, 0, 0) reflection and for the $P\parallel z$ configuration on the (2, 0, 1) reflection and a scan through (1, 0, 1) along $c^{\ast }$. In panel (a) the background given by the NSF scattering corrected by the temperature dependence of the flipping ratio $R\left(T\right)$ (blue circles) is compared with the SF scattering (red squares) for the Bragg (2, 0, 1). Panels (b) and (c) show the SF scattering (red squares) and NSF/$R\left(T\right)$ (blue points) for the $P\parallel Q$ and $P\parallel z$ polarization directions for (1, 0, 0) [$(R\left(T\right)=R\left(300\text{K}\right)\left\{1+0.06\left(1-T/300\right)\right\}\phantom{)}$ has been determined from Fig. 3b]. The difference between both curves shows the magnetic scattering. (d) shows a scan along $L$ for the (1, 0, 1) position taken in the $P\parallel Q$ polarization state of the magnetic scattering (red squares), obtained by the temperature difference of the SF scattering where NSF/$R\left(T\right)$ has been subtracted at each temperature [$R\left(T\right)=R\left(300\text{K}\right)\left\{1+0.02\left(1-T/300\right)\right\}$ as in Fig. 2]. The blue points show a NSF nonmagnetic scan of the Bragg peak normalized to the magnetic intensity. Results of panels (a)–(c) have been obtained with the same experimental setup, whereas the $L$ scan of panel (d) has been measured with the same experimental conditions as Fig. 2.Reuse & Permissions