Magnetoelasticity of Co₂₅Fe₇₅ thin films

We investigate the magnetoelastic properties of C o 25 F e 75 and C o 10 F e 90 thin films by measuring the mechanical properties of a doubly clamped string resonator covered with multilayer stacks containing these films. For the magnetostrictive constants, we find λ C o 25 F e 75 = (- 20.68 ± 0.25) × 10 - 6 and λ C o 10 F e 90 = (- 9.80 ± 0.12) × 10 - 6 at room temperature, in contrast to the positive magnetostriction previously found in bulk CoFe crystals. C o 25 F e 75 thin films unite low damping and sizable magnetostriction and are thus a prime candidate for micromechanical magnonic applications, such as sensors and hybrid phonon-magnon systems.