Damping Enhancement in Coherent Ferrite-Insulating-Paramagnet Bilayers

Published

November 19, 2019

Author(s)

Jacob J. Wisser, Alexander Grutter, Dustin A. Gilbert, Alpha T. N'Diaye, Christoph Klewe, Padraic Shafer, Elke Arenholz, Yuri Suzuki, Satoru Emori

Abstract

High-quality epitaxial ferrites, such as low-damping MgAl-ferrite (MAFO), are promising nanosclae building blocks for all-oxide heterostructures driven by pure spin current. However, the impact of oxide interfaces on spin dynamics in such heterostructures remains an open question. Here, we investigate the spin dynamics and chemical and magnetic depth profiles of 15-nm-thick MAFO coherently interfaced with an isostructural overlayer of paramagnetic CoCr₂O₄ (CCO) as an all-oxide model system. Compared to MAFO without an over layer, effective Gilbert damping in MAFO/CCO is enhanced by a factor of >3, irrespective of the CCO overlayer thickness. We attribute the giant damping enhancement to spin scattering at the 1-nm-thick chemically disordered layer at the MAFO/CCO interface, rather than spin pumping or proximity-induced magnetism. Our results indicate that damping in ferrite-based heterostructures is strongly influenced by interfacial chemical disorder, even if the thickness of the disordered layer is a small fraction of the ferrite thickness.

Citation

Physical Review Applied

Volume

12

Issue

5

Pub Type

Journals

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Keywords

Spin pumping, spintronics, magnetic insulator, spinel, magnetism, oxide, film

Citation

Wisser, J. , Grutter, A. , Gilbert, D. , N'Diaye, A. , Klewe, C. , Shafer, P. , Arenholz, E. , Suzuki, Y. and Emori, S. (2019), Damping Enhancement in Coherent Ferrite-Insulating-Paramagnet Bilayers, Physical Review Applied, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=928664 (Accessed October 22, 2025)