FERROMAGNETIC RESONANCE IN BA4ZN2FE36O60 (ZNU) AND MN-SUBSTITUTED ZNU SINGLE CRYSTALS

Resonance experiments were performed on Ba4Zn2Fe 36O60 (ZnU) and Mn-substituted ZnU single crystal spheres using a reflection technique and transverse pumping. The influence of surface polish on linewidth was studied from 26.5-40 GHz at 300°K. In general, ΔH was found to be only slightly dependent upon frequency. The lowest linewidth was 18.5 Oe measured on a Mn-substituted ZnU sample at 26.5 GHz. 4πMs, HA, ΔH, and γeff values are presented at 4.2°, 77°, and 300°K. A bandpass filter was constructed using a spherical resonator in an orthogonal configuration. The electrical characteristics are as follows: (1) Passband insertion loss, L a=3.1-5.4 dB; (2) 3 dB bandwidth =200-380 MHz; (3) Stopband attenuation =30 dB, except spurious modes which are greater than 10 dB below main resonance. © 1969 The American Institute of Physics.