Mössbauer effect diffraction from polycrystalline57Fe

Mössbauer diffractometry on polycrystalline57Fe3Al

“…Quantification of diffraction intensities with kinematical theory is an advantage in principle of performing Mössbauer diffraction experiments on polycrystalline samples. Mössbauer powder diffraction patterns have not been obtained until recently, however, 34 owing to the low intensities of the diffraction peaks.…”

Intensities of Mössbauer diffractions from polycrystalline bcc57Fe

“…Tegze and Faigel 11 built a focusing Mössbauer diffractometer and measured energy spectra during the diffraction of a polycrystalline iron sample. Full diffraction patterns were first measured on polycrystals by Stephens et al 12 Mössbauer diffraction has successfuly employed hyperfine interactions to select the chemical environment of the diffracting species. 13 The signal-to-noise ratios of previous measurements have been inadequate for quantitative measurements of powder diffraction intensities.…”

Site-specific long-range order in57Fe3Al measured by Mössbauer diffractometry

“…The present Mo¨ssbauer diffractometry measurements were planned with the intention of using the single-scattering kinematic theory for data interpretation (O'Conner andBlack 1964, Belyakov 1975). The past decade has seen improvements in both instrumentation and theory for Mo¨ssbauer powder diffractometry in the kinematic limit (Tegze and Faigel 1994, Stephens et al 1994, Stephens 1996, Stephens and Fultz 1997, Fultz and Stephens 1998. Stephens and Fultz (1997) first showed how 57 Fe atoms with specific chemical environments could be selected for diffraction by tuning the energy of the g-ray photons.…”

“…Kinematic theory would be appropriate for X-ray diffractometry of Fe 3 Al, but the cross-section for nuclear 2622 J. Y. Y. Lin and B. Fultz resonance scattering by 57 Fe is 10 4 times larger than the cross-section for coherent X-ray scattering by the electrons of an Fe atom. To test the reliability of kinematic theory, we modelled a polycrystal as small single crystals in which the diffractions were treated with dynamic theory using the software package CONUSS (Sturhahn and Gerdau 1994, Sturhahn 2000, Rohlsberger 2002. We found that the sample used in the present experiment was in the kinematic limit.…”

“…Calculations with the dynamic theory 3.1. CONUSS CONUSS is a software package for calculating the nuclear-resonance scattering of photons (Sturhahn 2000). It implements the quantum electrodynamic theory of Hannon and Trammel (1968) for the coherent scattering of g-ray and X-ray photons by the nucleus and the electrons of each atom.…”