Angular dependence, blackness and polarization effects in integral conversion electron M\"ossbauer spectroscopy

Abstract

General expressions of the electron yield in (^{57})Fe integral conversion electron M\"ossbauer spectroscopy were derived depending on the angle of incidence of the (\gamma)-rays, on the source polarization and on the isotopic abundance of the source and the absober (blackness effects) using an exponential escape function of the electrons originating from all M\"ossbauer-resonance-related processes. The present approach provides a firm theoretical basis to determine the alignment and direction of magnetization in the absorber. The intensity formulae were justified by least squares fits of (\alpha-^{57})Fe spectral intensities measured in linearly and elliptically polarized source and absorber geometries. The fits reproduce the experimentally set angles with high accuracy. Limits of the current approach and its relation to other, less complete treatments in the literature are discussed.