Characterization of electrodeposited thin layers of magnetic alloys by Mossbauer spectroscopy

Rare earth and transition metal alloys are interesting magnetic materials f or applications in the field of magnetooptical memories. We describe the pr eparation of Dy/Fe alloys by electrodeposition using a pulsed galvanostatic process. Samples were characterized by Mossbauer spectroscopy. Thin layers obtained with short electrolysis pulses (0.1 s) give a Mossbauer spectrum analysed as the sum of two subspectra: the first corresponds to a spectrum originating from very small sized particles of Fe and the second is attribu ted to a Dy/Fe phase. Longer electrolysis pulses (1 s) give samples whose s pectrum is also the sum of two subspectra: the first is attributed to metal lic Fe with an extended particle-size distribution while the second is attr ibuted to a Fe/Dy alloy. Mossbauer spectroscopy was found useful in determi ning the best electrolysis parameters leading to domains of uniform magneti zation with high coercive fields.