Mossbauer-effect study of amorphous Tb1-xFex films

Amorphous a-Tb1-xFex alloy films (0.50 less than or equal to x less than or equal to 0.90) deposited by co-evaporation in UHV onto Si wafers held at 300 K, have been investigated by conversion electron Mossbauer spectroscopy (GEMS). All a-Tb1-xFex films show preferential (but incomplete) perpendicular Fe spin orientation with average tilting angles [Theta] approximate to 20-30 degrees, independent of temperature T between 20 K less than or equal to T less than or equal to 300 K. The average hyperfine field [B-hf(0)] at saturation was found to depend linearly on x via the relation [B-hf(0 K)] = 39.9T - J .(g - 1).(1 - x). 16.3T, where g = 1.5 and J = 6 for Tb3+. For x greater than or equal to 0.85 the precipitation of bcc Fe was observed.