Mössbauer Determination of the Debye-Waller Factor in Single-Crystal Absorbers

The equation which must be used to obtain the Debye-Waller factor $f^{\prime }$ from Mössbauer absorption measurements on single-crystal samples with resolved and hence generally polarized lines is given. The polarization terms for a crystal having the symmetry of siderite are explicitly presented and theoretical area ratios are compared with recently reported values calculated from a theory neglecting polarization. New experimental data indicate that $f^{\prime }>~0.6$ for all directions in siderite.