Figure 1

(Color online) Illustration of the density of states $D^{\uparrow \downarrow }\left({\epsilon }_F\right)$ of a ferromagnet near the Fermi level ${\epsilon }_F$ (Ref. 18). Difference of $D^{\uparrow \downarrow }\left({\epsilon }_F\right)$ integrated from the bottom of the band to ${\epsilon }_F$ is the net (spin) magnetization. The integrated DOS for spin-up and spin-down electrons are shown by green (right) and red (left) areas, accordingly. Shift of ${\epsilon }_F$ to ${\epsilon }_F^{\prime }$ changes the green and red integrals differently, thus changing the magnetization.Reuse & Permissions

Figure 2

(Color online) Schematic of the electrochemical cell. A 3 kOe field was parallel to the sample surface; $E$ field was obtained by applied potential $U$ measured against reference electrode.Reuse & Permissions

Figure 3

(Color online) Control measurements to monitor the time dependence of the change in the sample’s reflectivity. Measurements shown in Fig. 4 were taken after the sample’s reflectivity no longer changed with time.Reuse & Permissions

Figure 4

(Color online) (a) Reflectivity data taken without electrolyte. Solid black and dashed red curves represent the fit to the data. (b) NSD data, the fitted curve (solid curve), and the NSD residuals ${\widehat{\epsilon }}_{\text{NSD}}$; (c) variation in the model parameters for the nuclear (black line is the “NSLD”) and magnetic (dashed blue line is $M$) SLDs used to produce the curves in figures (a) and (b).Reuse & Permissions

Figure 5

(Color online) (a) NSD data for different applied potentials and fits to the data. The 95% confidence bands are shown. These bands do not overlap at high $Q$. [(b)–(d)] NSD data and the fitted curves (solid red lines) for $U=-0.02\text{V}$, $U=-0.15\text{V}$, and $U=-0.32\text{V}$, respectively.Reuse & Permissions

Figure 6

(Color online) (a) Schematic of the model to fit the data. (b) Variation in the model parameters (dashed green, dotted red, and dashed dotted blue lines) corresponding to (a) for the magnetization of CoPd film as a function of $U$ (associated with “$M$” scale) and nuclear SLD (the solid black line associated with NSLD scale). The nuclear SLD is the same for all three measurements.Reuse & Permissions

Figure 7

(Color online) Magnetization of top 7.2 nm of CoPd film [layer 2 in Fig. 6a]. Elapsed time of the experiment and evolution of the magnetization are indicated. The magnetization inferred from the last measurement—one with an applied potential of $-0.02\text{V}$—is statistically the same as the first measurement—one without an applied potential.Reuse & Permissions