Magnetism and recoilless fraction in metallic glasses after laser irradiation

Samples of Fe78B13Si9 (Metglas 2605 TCA) and Fe77Cr2B16Si5 (Metglas 2605 S3A) were exposed to pulsed excimer laser irradiation at repetition rates of 15, 25 and 50 Hz. The occurrence of out-of-plane magnetic anisotropy, changes in the average hyperfine magnetic field and width of the hyperfine field distribution were evidenced by transmission Mِssbauer spectroscopy. The variation of the recoilless fraction with laser processing parameters was derived from the simultaneous recording of Mِssbauer spectra using a stainless steel etalon as a dual absorber. Conclusions on the onset of long-range magnetic order were formulated.