Figure 2

Polarized neutron reflectometry.

Polarized neutron reflectivity of L1₀-FePt(4 nm)/A1-FePt(t_A1) with (a) t_A1 = 2 nm and (b) t_A1 = 5 nm, where the non-spin-flip channels are identified as black solid squares (R⁺⁺) and blue solid circles (R⁻⁻) and spin-flip ones as red open triangles (R⁺⁻) and green open inverted triangles (R⁻⁺). Schematic insets show the spin configurations in the L1₀ layer (red) and A1 layer (purple), respectively. The corresponding nuclear and magnetic scattering length density (SLD) depth profiles for the samples with t_A1 of 2 nm and 5 nm are shown in panels (c) and (d), respectively, which are also used to calculate the reflectivity shown in (a,b) as solid lines. The nuclear depth profile is shown as a black line, and the magnetic profile as a red line; background colors from left to right identify the SiO₂ (grey), L1₀-FePt (coral), A1-FePt (light purple), Ti Cap (green), and air (white).