Spin transport in an insulating ferrimagnetic-antiferromagnetic-ferrimagnetic trilayer as a function of temperature

Yizhang Chen; Egecan Cogulu; Debangsu Roy; Jinjun Ding; Jamileh Beik Mohammadi; Paul G. Kotula; Nancy A. Missert; Mingzhong Wu; Andrew D. Kent

doi:10.1063/1.5116549

AIP Advances (Oct 2019)

Spin transport in an insulating ferrimagnetic-antiferromagnetic-ferrimagnetic trilayer as a function of temperature

Yizhang Chen,
Egecan Cogulu,
Debangsu Roy,
Jinjun Ding,
Jamileh Beik Mohammadi,
Paul G. Kotula,
Nancy A. Missert,
Mingzhong Wu,
Andrew D. Kent

Affiliations

Yizhang Chen: Center for Quantum Phenomena, Department of Physics, New York University, New York, New York 10003, USA
Egecan Cogulu: Center for Quantum Phenomena, Department of Physics, New York University, New York, New York 10003, USA
Debangsu Roy: Center for Quantum Phenomena, Department of Physics, New York University, New York, New York 10003, USA
Jinjun Ding: Department of Physics, Colorado State University, Fort Collins, Colorado 80523, USA
Jamileh Beik Mohammadi: Center for Quantum Phenomena, Department of Physics, New York University, New York, New York 10003, USA
Paul G. Kotula: Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
Nancy A. Missert: Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
Mingzhong Wu: Department of Physics, Colorado State University, Fort Collins, Colorado 80523, USA
Andrew D. Kent: Center for Quantum Phenomena, Department of Physics, New York University, New York, New York 10003, USA

DOI: https://doi.org/10.1063/1.5116549
Journal volume & issue: Vol. 9, no. 10
pp. 105319 – 105319-5

Abstract

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We present a study of the transport properties of thermally generated spin currents in an insulating ferrimagnetic-antiferromagnetic-ferrimagnetic trilayer over a wide range of temperature. Spin currents generated by the spin Seebeck effect (SSE) in a yttrium iron garnet (YIG) YIG/NiO/YIG trilayer on a gadolinium gallium garnet (GGG) substrate were detected using the inverse spin Hall effect (ISHE) in Pt. By studying samples with different NiO thicknesses, the spin diffusion length of NiO was determined to be ∼3.8 nm at room temperature. Surprisingly, a large increase of the SSE signal was observed below 30 K, and the field dependence of the signal closely follows a Brillouin function for an S=7/2 spin. The increase of the SSE signal at low temperatures could thus be associated with the paramagnetic SSE from the GGG substrate. Besides, a broad peak in the SSE response was observed around 100 K. These observations are important in understanding the generation and transport properties of spin currents through magnetic insulators and the role of a paramagnetic substrate in spin current generation.

Published in AIP Advances

ISSN: 2158-3226 (Online)
Publisher: AIP Publishing LLC
Country of publisher: United States
LCC subjects: Science: Physics
Website: http://aipadvances.aip.org/

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