Some improvement in Fe/Si multilayered neutron polarizor by modified sputtering geometry

Aperture geometry of magnetron sputtering unit was modified by insertion of longitudinal [B] and transverse [A] slits with respect to the motion of substrate. Fe-, Si-mono and Fe/Si multilayer [Fe (70 Å)/Si (50 Å)]10 (called ML70) were grown with and without modified apertures. Maximum stress anisotropy was found in samples prepared with transverse modified aperture [A]. X-ray reflectometry (XRR) results showed a marked difference in roughness values of interdiffusion layers Fe-Si and Si-Fe. Magnetic measurements showed coercive field strength of 50 Oe in ML70 prepared by modified aperture geometry Fe[A]/Si[O]. A significant improvement in the neutron polarization efficiency is observed in multilayer ML70 with the use of modified aperture geometry as compared to similar sample prepared by normal aperture.