Resonance properties of single-crystal hexagonal ferrites over X-band frequencies

Resonance measurements have been performed on single-crystal spheres of the hexagonal planar ferrite Zn2Y and Zn1.5Mn0.5Y from 8.2 to 12.4 Gc/s. The linewidth and the resonant magnetostatic field were measured at room temperature for two different cases: 1) applied magnetostatic field in the easy plane with rotation about an axis parallel to the field, and 2) magnetostatic field at fixed angles with respect to the easy plane with rotation about an axis parallel to the field. Linewidths of approximately 82 Oe and 19 Oe for Zn2Y and Zn1.5Mn0.5Y, respectively, are reported for the first case with approximately a sinusoidal variation in linewidth vs. angular rotation. The amplitude of this sinusoidal variation was 3 to 4 Oe for both materials. For the second case, the linewidth of Zn1.5Mn0.5Y at 8.9 Gc/s increased from 20 Oe to 90 Oe as the angle between the magnetostatic field and the easy plane increased from 0 to 75 degrees. A comparison is made between theory and experiment for the resonant magnetostatic field vs. frequency for the first case and for the resonant magnetostatic field vs. the angle between the field and the easy plane for the second case.