HIGH NEUTRON BEAM POLARIZATION WITH MN3+XSN CRYSTALS

Mn3+xSn has a high neutron polarization efficiency for its (1 0 0) and (1 1 0) reflections, thus suggesting a high potential for use as a no n-ferromagnetic polarizing monochromator. In the present work, the fli pping ratio for these reflections of Mn,,,Sn has been measured by vary ing the Mn concentration. A flipping ratio larger than that of Cu2MnAl (1 1 1) has been observed for the (1 0 0) reflection of Mn3.2Sn and Mn 3.4Sn crystals. The optimal flipping ratio of all these has been obser ved for the (1 0 0) reflection of a quenched crystal of Mn3.2Sn. The c oncentration dependence of the flipping ratio suggests that the excess Mn atoms occupying an Sn site are paramagnetic and that the spin-flip scattering from these Mn atoms reduces the flipping ratio with the in crease of Mn concentration. Hence, the flipping ratio is dependent upo n Mn concentration and heat treatments. (C) 1998 Published by Elsevier Science B.V. All rights reserved.