Magnetostrictive Fe-Si thin films for tunable SAW devices

RF sputtered films of Fe
x
Si
1-x
, where
x \approx .7
, deposited on YZ-LiNbO
3
, have been used for magnetically variable surface acoustic wave devices. A 1 micron thick film one cm long in the SAW propagation direction had a relative SAW velocity change of 0.02% at 63 MHz and 0.05% at 189 MHz for applied fields of less than 50 Oe after annealing at 200°C for 30 minutes. Magnetic properties (M-H loops and magnetostriction) of the films were measured and correlated with the SAW properties.