title: Determination of the exchange constant of Tb0.3Dy0.7Fe2by broadband ferromagnetic resonance spectroscopy.
abstract: We present measurements of the exchange stiffnessDand the exchange constantAof a sputtered 80 nm Tb0.3Dy0.7Fe2film. Using a broadband ferromagnetic resonance setup in a wide frequency range from 10 GHz to 50 GHz, multiple perpendicular standing spin-wave resonances were observed with the external static magnetic field applied in-plane. The field corresponding to the strongest resonance peak at each frequency is used to determine the effective magnetization, theg-factor and the Gilbert damping. Furthermore, the dependence of spin-wave mode on field-position is observed for several frequencies. The analysis of spin-wave resonance spectra at multiple frequencies allows precise determination of the exchange stiffnessD= (2.79 ± 0.02) × 10-17T · m2for an 80 nm thick film. From this value, we calculated the exchange constantA= (9.1 ± 0.1) pJ · m-1.
authors.affiliation: Materials Science and Engineering Division, NIST, Gaithersburg, MD 20899, USA.
authors.forename: D B
authors.initials: DB
authors.lastname: Gopman
authors.affiliation: Materials Science and Engineering Division, NIST, Gaithersburg, MD 20899, USA.
authors.forename: J W
authors.initials: JW
authors.lastname: Lau
authors.affiliation: Department of Mechanical and Aerospace Engineering, University of California, Los Angeles, CA 90095, USA.
authors.forename: K P
authors.initials: KP
authors.lastname: Mohanchandra
authors.affiliation: Department of Mechanical and Aerospace Engineering, University of California, Los Angeles, CA 90095, USA.
authors.forename: K
authors.initials: K
authors.lastname: Wetzlar
authors.affiliation: Department of Mechanical and Aerospace Engineering, University of California, Los Angeles, CA 90095, USA.
authors.forename: G P
authors.initials: GP
authors.lastname: Carman