Mechanism for the interaction of surface waves with 200‐Å nickel films

Measurements of the surface wave attenuation of surface wave delay lines coated with nickel films in a magnetic field parallel to the film plane in the frequency range 500–665 MHz exhibit attenuation peaks which depend strongly on film thickness, temperature, and magnetic field. The effect is very strong for 200‐A thick nickel film‐coated 618‐MHz quartz delay lines at room temperature. The maximum attenuation change is about 40 db/cm. The attenuation can be varied by over 25 db/cm by a magnetic field change of less than 10 Oe. A 665‐MHz LiNbO3 delay line coated with a 200‐A nickel film exhibits a maximum attenuation of about 10 db/cm and similar behavior to that seen on the quartz substrate in a magnetic field. Thicker films exhibit similar but smaller attenuation peaks. Attenuation measurements were carried out at various temperatures. In general, the maximum attenuation decreases at lower temperature and the peaks occur at higher field values. Attenuation measurements in a pulsed magnetic field demonstr...