Absorber thickness dependence of α-Fe cyclic Mössbauer Magnetic Scans

G. A. PASQUEVICH; P. MENDOZA ZÉLIS; M. B. FERNÁNDEZ VAN RAAP; F. H. SÁNCHEZ

Iguazú, Argentina

Congreso; XIV International Conference on Hyperfine Interactions (HFI 2007) and XVIII International Symposium on Nuclear Quadrupole Interactions (NQI 2007); 2007

Recently we have proposed the study of the Mössbauer absorption at a fixed energy as a function of an applied magnetic field, a method which we will refer to as Mössbauer Magnetic Scans (MMS). In this work we study the thickness effect on cyclic MMS performed at different spectral absorption lines. To this end we use 13μm α-Fe foil and 1 μm thin film absorber. MMS were taken at the fourth, fifth and sixth Mössbauer absorption lines. The motivation for this work arises from the results on MMS recently obtained from NANOPERM (Fe90Zr7B3) alloys, where this technique was tested for the first time. In that work, the feasibility of MMS experiments as a magnetic local characterization technique was demonstrated. The results were interesting and proved to provide complementary information to that obtained from magnetic induction cycles. They also showed that discrimination among magnetic responses coming from different phases is feasible. The experimental results indicate that the field dependence of absorption lines could not be understood considering only the theoretical angular dependence of the transition probabilities. We probe here that both saturation and polarization effects can explain the field dependence of the absorption lines.