Discovery of giant magnetostriction in annealed Co1-xFex thin-films

Published

November 1, 2011

Author(s)

Dwight Hunter, William Alexander Osborn, Ke Wang, Nataliya Kazantseva, Jason Hattrick-Simpers, Richard Suchoski, Ryota Takahashi, Marcus L. Young, Apurva Mehta, Leonid A. Bendersky, Sam E. Lofland, Manfred Wuttig, Ichiro Takeuchi

Abstract

Chemical and structural heterogeneity and resulting interaction of coexisting phases can lead to extraordinary behaviors in oxides as observed in piezoelectric materials at morphotropic phase boundaries and relaxor ferroelectrics. But such phenomena are rare in metallic alloys. Here, we show that by tuning the presence of structural heterogeneity in textured Co1-xFex thin films, effective room-temperature magnetostriction λeff as large as 260 ppm can be achieved at low saturation field of < 10 mT. Assuming λ100 is the dominant component, this number translates to the upper limit of magnetostriction of λ100 ≈ 5λeff > 1000 ppm, rivaling magnetostriction attained in rare-earth containing Terfenol, which requires saturation field > 0.1 T. Synchrotron diffraction and electron microscopy analyses of our Co1-xFex films indicate that the maximum in magnetostriction occurs at compositions close to the (fcc+bcc)/bcc phase boundary and originates from the precipitation of an equilibrium Co-rich fcc phase embedded in a Fe-rich bcc matrix. These results together with reported observations of large magnetostriction in Fe1-xGax alloys indicate that the recently proposed heterogeneous magnetostriction mechanism can be used to guide exploration of other novel compounds with unusual magnetoelastic properties.

Citation

Nature Materials

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Keywords

Magnetostriction, Iron, Fe, Cobalt, Co, Combinatorial Thin Films, Magnetic properties, Microelectromechanical System, MEMS

Citation

Hunter, D. , Osborn, W. , Wang, K. , Kazantseva, N. , Hattrick-Simpers, J. , Suchoski, R. , Takahashi, R. , Young, M. , Mehta, A. , Bendersky, L. , Lofland, S. , Wuttig, M. and Takeuchi, I. (2011), Discovery of giant magnetostriction in annealed Co1-xFex thin-films, Nature Materials, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=908822 (Accessed September 26, 2023)