Standing spin waves in perpendicularly magnetized circular dots at millimeter waves

• Published in: Journal of applied physics 2013-05, Vol.113 (17)
• Main Authors: Nedukh, S. V., Tarapov, S. I., Belozorov, D. P., Kharchenko, A. A., Golub, V. O., Kilimchuk, I. V., Salyuk, O. Y., Tartakovskaya, E. V., Bunyaev, S. A., Kakazei, G. N.
• Format: Article
• Language: English
• ISSN: 0021-8979; 1089-7550
• DOI: 10.1063/1.4799528

Spin wave spectra of 40-nm thick perpendicularly magnetized circular Permalloy dots of 250 nm radius were measured using ferromagnetic resonance technique in 70-80 GHz range at 4.2 K and in 10 GHz at room temperature. The five sharp resonance peaks were observed for both frequency ranges. The resonance fields can be well described by a magneto-exchange dispersion relation, implying that the observed resonances correspond to circular “drumhead” modes with Bessel-function profiles. The relative distances between neighbor peaks for different frequency ranges were almost the same, while the absolute interpeak distances in millimeter range were ∼30% bigger than at 10 GHz, as predicted by the theory.