Coexistence of Low Damping and Strong Magnetoelastic Coupling in Epitaxial Spinel Ferrite Thin Films

Abstract

Low-loss magnetization dynamics and strong magnetoelastic coupling are generally mutually exclusive properties due to opposing dependencies on spin-orbit interactions. So far, the lack of low-damping, magnetostrictive ferrite films has hindered the development of power-efficient magnetoelectric and acoustic spintronic devices. Here, magnetically soft epitaxial spinel NiZnAl-ferrite thin films with an unusually low Gilbert damping parameter (<3 × 10 ), as well as strong magnetoelastic coupling evidenced by a giant strain-induced anisotropy field (≈1 T) and a sizable magnetostriction coefficient (≈10 ppm), are reported. This exceptional combination of low intrinsic damping and substantial magnetostriction arises from the cation chemistry of NiZnAl-ferrite. At the same time, the coherently strained film structure suppresses extrinsic damping, enables soft magnetic behavior, and generates large easy-plane magnetoelastic anisotropy. These findings provide a foundation for a new class of low-loss, magnetoelastic thin film materials that are promising for spin-mechanical devices.

Controlling acoustic waves using magneto-elastic Fano resonances

“…This, however, is also likely to enhance the phonon contribution to the magnetic damping, leading to a correlation between B and α observed in realistic magnetic materials. 49 To characterise the strength of the Fano resonance, we note that the fate of the magnon excited by the incident acoustic wave is decided by the relation between the emission rate Γ R , see Eq. (14), and absorption rate Γ FMR .…”

Damping Enhancement in Coherent Ferrite–Insulating-Paramagnet Bilayers

“…To quantify effective damping in coherently strained MAFO(/CCO) thin films, we performed broadband FMR measurements at room temperature in a coplanar waveguide setup using the same procedure as our prior work 16,18 . We show FMR results with external bias magnetic field applied in the film plane along the [100] direction of MAFO(/CCO); essentially identical damping results were obtained with in-plane field applied along [110] 47 .…”

“…Low-dissipation spintronic devices become particularly attractive if insulating ferrite thin films with low magnetic damping can serve as sources of magnon spin currents. Such low-damping ferrites include not only epitaxial garnet ferrites (e.g., YIG) [3][4][5][6][7][8][9][10][11] that have been widely used in studies of insulating spintronics [2][3][4][12][13][14][15] , but also coherently strained epitaxial spinel ferrites [16][17][18] with crucial technical advantages over garnets, such as lower thermal budget for crystallization, higher magnon resonance frequencies, and potential to be integrated coherently with other spinels and perovskites with various functionalities [19][20][21][22] .…”

Nanostructure‐enhanced magnetoelectric/magnetostrictive properties and reduced losses in self‐assembled epitaxial CuFe2O4–BiFeO3 layers on Pb(Mg1/3Nb2/3)O3–33at%PbTiO3 crystals

“…15 Previous studies to have attempted to achieve both high Q and high λ m in epitaxial thin films, 16,17 but, it has proven difficult to achieve both conditions simultaneously. 16 Although, Howe et al 18 have recently reported an optimum tradeoff between high Q and λ m for NiZnAl-ferrite.…”