CHEMICAL VAPOR DEPOSITION OF THIN FILM MATERIALS FOR ...

measurement, 0 degree represents the static magnetic field pointing at the [100] direction of the
single crystal. The in-plane cubic anisotropy can be clearly observed by the shift of the resonance
field at different orientations with the easier axis pointing at [110] direction. This is reasonable
considering that the easy axis is in the [111] direction in a bulk nickel ferrite single crystal.
Fig. 50. In plane FMR curves measured at different angles of the sample to the static magnetic field. The inset
shows the line width value vs. in plane angle.
The in plane and out-of-plane FMR curves are showed in Fig.51. As can be seen, both the
resonance field and the FMR line width have a big difference between the in plane and out-of-
plane measurement. The shift of the resonance field to a much higher position for the out-of-
plane measurement indicates the presence of a large magnetic anisotropy with easy axis parallel
to the thin film surface. The decreasing FMR line width from 752 to 160 Oe can be attributed to
the decreased two magnon scattering effect for the out-of-plane measurement.[171] It has been
proved that the coupling effect between the uniform FMR mode and degenerate spin waves is
angle dependent for thin film materials. More specifically, when the magnetic field is parallel to
the thin film surface, there are a large number of spin wave states which are degenerate with the
uniform mode and a significant contribution to the two magnon scattering line width is possible.
When the magnetic field is perpendicular to the thin film surface, there are essentially no spin
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