Anomalous transmission and Pendelloesungen in electronically allowed nuclear Laue diffraction of Moessbauer radiation

Nuclear resonant dynamical diffraction in transmission geometry was studied in case of an electronically allowed reflection. Moessbauer diffraction spectra were measured for both the Laue reflected and the Laue forward transmitted beam with high angular resolution. Pronounced energy Pendelloesung beats were observed in the LR-beam. Complementary beats were identified in the LT-beam, where also a strong suppression of nuclear resonance absorption and variations in the anomalous electronic absorption were revealed. (orig.)