Anisotropic Spin-Wave Propagation in Ferrites

• Published in: Journal of applied physics 1965-01, Vol.36 (11), p.3402-3404
• Main Authors: Sethares, James C., Purnhagen, Tom G.
• Format: Article
• Language: English
• ISSN: 0021-8979; 1089-7550
• DOI: 10.1063/1.1703005

A directional dependence of the propagation of nonlinearly excited spin waves in anisotropic ferrites has been observed by measuring the radiation from the edge of a (110) YIG disk. The disk was excited by a parallel pump field normal to its plane and rotated through 360 deg. Measurements were made at dc field intervals of 10 Oe from 1800 to 2800 Oe (the experimental minimum of the butterfly curve). Radiation was observed at half the parallel pump frequency over a dc field range of 248 Oe (from 2294 to 2542 Oe). The direction for maximum radiation was along a [1̄10] axis in the plane of the disk, and a strong directional dependence was observed when the pump field was less than 4 dB above threshold. The ratio of maximum to minimum output as the disk was rotated was at least 10 dB. The directional dependence was found to be essentially independent of pump field strength up to 4 dB above threshold. Any further increase in pump field strength reduced the amount of radiation, and for pump field strengths higher than 8 dB above threshold no radiation was observed.