Polarized neutron reflection, or PNR, is [28,29] an established experimental technique for the measurement of layer-dependent magnetization vector in magnetic multi-layers. A multi-layer structure is [28,29] modelled as a series of steps in nuclear potential and magnetic flux density. The amplitude reflection coefficient for neutron waves at each step is then calculated by applying the usual [30] boundary conditions to the spin-up and spin-down wave-functions at the step, given the change in wave-vector produced by the potential step. The change in wave-vector depends on the neutron's spin direction because of the torque exerted upon the neutron magnetic moment, by the magnetic field. Therefore, the spin polarization of the reflected neutron beam, as a function of incident beam energy, provides an indicator of the depth-resolved magnetization profile of the sample.