Intrinsic Exchange Bias in Epitaxial CoFe2O4/Al<sub>2</sub>O<sub>3</sub> thin film
ORAL
Abstract
Exchange bias (EB), traditionally known as an interface phenomenon between ferro- or ferrimagnetic (FM) materials and antiferromagnetic (AFM) materials, has been widely applied in magnetic storage and spintronic devices. As one striking emergent phenomenon of oxide interfaces featured by strong interactions and reconstruction among spins, charges and lattice, “intrinsic” EB (IEB) effect without a nominal AFM layer has drawn much attention. To elucidate the mechanism of IEB, we grew CoFe2O4 (111) thin films epitaxially on sapphire (0001) substrates by pulsed laser deposition and studied their magnetic and structural properties. EB was observed when the magnetic field is in both the out-of-plan and the in-plane direction. The structural analysis using time-resolved reflection high energy electron diffraction during the growth, suggests that an AFM layer has developed between the substrate and the CoFe2O4 thin film. The power-law of the thickness-dependence of IEB indicate the interfacial origin. The temperature dependences of IEB and coercivity indicate a structural phase transition emerges at about 25 K. This work suggests a potential application of adjustable EB and provide new platforms to probe the mechanism of intrinsic EB.
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Presenters
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Detian Yang
Physics & Astronomy, University of Nebraska-Lincoln, University of Nebraska - Lincoln
Authors
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Detian Yang
Physics & Astronomy, University of Nebraska-Lincoln, University of Nebraska - Lincoln
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Yu Yun
Physics & Astronomy, University of Nebraska-Lincoln, University of Nebraska - Lincoln
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Xiaoshan Xu
Physics & Astronomy, University of Nebraska-Lincoln, Nebraska Center for Materials and Nanoscience and Department of Physics and Astronomy, University of Nebraska - Lincoln, University of Nebraska-Lincoln, University of Nebraska - Lincoln, Department of Physics and Astronomy, University of Nebraska - Lincoln, Physics and Astronomy, University of Nebraska-Lincoln