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

Satoru Emori; Benjamin A Gray; Hyung-Min Jeon; Joseph Peoples; Maxwell Schmitt; Krishnamurthy Mahalingam; Madelyn Hill; Michael E McConney; Matthew T Gray; Urusa S Alaan; Alexander C Bornstein; Padraic Shafer; Alpha T N'Diaye; Elke Arenholz; Greg Haugstad; Keng-Yuan Meng; Fengyuan Yang; Dongyao Li; Sushant Mahat; David G Cahill; Pallavi Dhagat; Albrecht Jander; Nian X Sun; Yuri Suzuki; Brandon M Howe

doi:10.1002/adma.201701130

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

Adv Mater. 2017 Sep;29(34). doi: 10.1002/adma.201701130. Epub 2017 Jul 10.

Authors

Satoru Emori¹, Benjamin A Gray², Hyung-Min Jeon³, Joseph Peoples², Maxwell Schmitt², Krishnamurthy Mahalingam², Madelyn Hill², Michael E McConney², Matthew T Gray¹, Urusa S Alaan¹, Alexander C Bornstein¹, Padraic Shafer⁴, Alpha T N'Diaye⁴, Elke Arenholz⁴, Greg Haugstad⁵, Keng-Yuan Meng⁶, Fengyuan Yang⁶, Dongyao Li⁷, Sushant Mahat⁷, David G Cahill⁷, Pallavi Dhagat⁸, Albrecht Jander⁸, Nian X Sun⁹, Yuri Suzuki¹, Brandon M Howe²

Affiliations

¹ Geballe Laboratory for Advanced Materials, Stanford University, Stanford, CA, 94305, USA.
² Materials and Manufacturing Directorate, Air Force Research Laboratory, WPAFB, OH, 45433, USA.
³ Department of Electrical Engineering, Wright State University, Dayton, OH, 45431, USA.
⁴ Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
⁵ College of Science and Engineering Characterization Facility, University of Minnesota, Minneapolis, MN, 55455, USA.
⁶ Department of Physics, The Ohio State University, Columbus, OH, 43210, USA.
⁷ Department of Materials Science and Engineering, University of Illinois, Urbana, IL, 61801, USA.
⁸ Department of Electrical Engineering and Computer Science, Oregon State University, Corvallis, OR, 97331, USA.
⁹ Department of Electrical Engineering, Northeastern University, Boston, MA, 02115, USA.

PMID: 28691378
DOI: 10.1002/adma.201701130

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^-3 ), 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.

Keywords: epitaxy; ferromagnetic resonance; magnetic damping; magnetostriction; spinel ferrite.