Direct observation of polarization mixing in nuclear Bragg x-ray scattering of synchrotron radiation

Abstract

The direct observation of polarization mixing in nuclear Bragg scattering of synchrotron radiation by \ensuremath{\alpha}${\mathrm{\ensuremath{-}}}^{57}$Fe${\mathrm{'}\mathrm{'}}_{2}$${\mathrm{O}}_{3}$ is reported. Application of a magnetic bias field having the appropriate orientation was shown to produce almost complete rotation of the \ensuremath{\sigma}-polarized incident beam to a \ensuremath{\pi}-polarized diffracted beam. Rotation of this field about the diffraction vector through 90\ifmmode^\circ\else\textdegree\fi{} caused the diffracted beam polarization to change continuously from \ensuremath{\sigma} through elliptical to \ensuremath{\pi}, as predicted theoretically.