Physics Commons^™

Probing Exchange Bias At The Surface Of A Doped Ferrimagnetic Insulator, Yang Wang, Xiao Wang, Andy T. Clark, Hang Chen, Xuemei Cheng, John W. Freeland, John Q. Xiao

Physics Faculty Research and Scholarship

With the realization of stress-induced perpendicular magnetic anisotropy, efficient spin-orbit torque switching, and room temperature topological Hall effect, interest in rare earth iron garnets has been revived in recent years for their potential in spintronic applications. In this study, we investigate the magnetic properties of micrometer-thick Bi and Ga substituted thulium iron garnets (BiGa:TmIG) grown by the liquid-phase epitaxy method. Above the magnetization compensation (MC) temperature, anomalous triple hysteresis is observed in BiGa:TmIG/Pt heterostructures by anomalous Hall effect measurements. X-ray magnetic circular dichroism and energy dispersive spectroscopy measurements reveal its origin as an internal exchange bias (EB) effect arising from …

Magnetization Dynamics In Coupled Thin Film Systems, Daniel J. Adams

University of New Orleans Theses and Dissertations

A study is presented detailing experimental investigations of magnetization dynamics in nanostructured systems which are coupled magnetically. This work seeks to characterize the anisotropy of such systems through experimental techniques which probe microwave resonant absorption in the materials.

A custom-built experimental setup, designed and assembled in our labs, is explained in detail. This setup allows for angular-dependent ferromagnetic resonance (FMR) measurements in the sample plane through vector network analyzer spectroscopy and is adaptable to two different types of coplanar waveguides. This technique has proven effective for characterization of multiple types of magnetic systems, including multilayered structures as detailed here, with …

Tailoring The Asymmetric Magnetoimpedance Response In Exchange-Biased Ni - Fe Multilayers, Ufuk Kilic, Carolina Ross, Carlos Garcia

Ufuk Kilic

Tuning The Effective Anisotropy In A Voltage-Susceptible Exchange-Bias Heterosystem, Will Echtenkamp, Mike Street, Ather Mahmood, Christian Binek

Christian Binek Publications

Voltage- and temperature-tuned ferromagnetic hysteresis is investigated by a superconducting quantum-interference device and Kerr magnetometry in a thin-film heterostructure of a perpendicular anisotropic Co/Pd ferromagnet exchange coupled to the magnetoelectric antiferromagnet Cr₂O₃. An abrupt disappearance of exchange bias with a simultaneous more than twofold increase in coercivity is observed and interpreted as a competition between the effective anisotropy of Cr₂O₃ and the exchange-coupling energy between boundary magnetization and the adjacent ferromagnet. The effective anisotropy energy is given by the intrinsic anisotropy energy density multiplied by the effective volume separated from the bulk through …

Exchange Bias Training Effect In Magnetically Coupled Bilayers, Srinivas Polisetty

Department of Physics and Astronomy: Dissertations, Theses, and Student Research

Interfaces in magnetically coupled bilayer heterostructures play a vital role in novel spintronics devices. Particularly, control of the interface spin structure enables the development of progressively down-scalable magnetic read-heads which are of major importance for non volatile magnetic recording media. Exchange bias and its accompanying training effect are fundamental magnetic coupling phenomena taking place at the interfaces of antiferromagnetic/ferromagnetic and hard/soft ferromagnetic bilayers. Here, in my thesis I present the experimental results of exchange bias training in the prototypical antiferromagnetic/ferromagnetic exchange bias system CoO/Co and the corresponding coupling and aging phenomena in the all ferromagnetic hard/soft bilayer CoPtCrB/CoCr. The latter …