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- Christian Binek Publications (3)
- Department of Physics and Astronomy: Faculty Publications (2)
- Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research (1)
- Department of Electrical and Computer Engineering: Faculty Publications (1)
- Ralph Skomski Publications (1)
Articles 1 - 8 of 8
Full-Text Articles in Physical Sciences and Mathematics
Direct Observation Of The Magnetic Anisotropy Of An Fe (Ii) Spin Crossover Molecular Thin Film, Ashley S. Dale, Saeed Yazdani, Thilini K. Ekanayaka, Esha Mishra, Yuchen Hu, Peter A. Dowben, John W. Freeland, Jian Zhang, Ruihua Cheng
Direct Observation Of The Magnetic Anisotropy Of An Fe (Ii) Spin Crossover Molecular Thin Film, Ashley S. Dale, Saeed Yazdani, Thilini K. Ekanayaka, Esha Mishra, Yuchen Hu, Peter A. Dowben, John W. Freeland, Jian Zhang, Ruihua Cheng
Department of Physics and Astronomy: Faculty Publications
Spin crossover molecules are a promising candidate for molecular spintronics that aim for ultrafast and low-power devices for data storage and magnetic and information sensing. The rapid spin state transition is best controlled by non-thermal methods including magnetic field. Unfortunately, the magnetic field normally required to switch the spin state is normally high (~30 T), which calls for better understanding of the fundamental mechanism. In this work, we provide clear evidence of magnetic anisotropy in the local orbital moment of a molecular thin film based on spin crossover complex [Fe(H2B(pz)2)2(bipy)] (pz = pyrazol−1−yl, bipy …
Dielectric Function Tensor (1.5 Ev To 9.0 Ev), Anisotropy, And Band To Band Transitions Of Monoclinic Β-(AlXGa1–X)2O3 (X ≤ 0.21) Films, Matthew Hilfiker, Ufuk Kilic, Alyssa Mock, Vanya Darakchieva, Sean Knight, Rafal Korlacki, Akhil Mauze, Yuewei Zhang, James Speck, Mathias Schubert
Dielectric Function Tensor (1.5 Ev To 9.0 Ev), Anisotropy, And Band To Band Transitions Of Monoclinic Β-(AlXGa1–X)2O3 (X ≤ 0.21) Films, Matthew Hilfiker, Ufuk Kilic, Alyssa Mock, Vanya Darakchieva, Sean Knight, Rafal Korlacki, Akhil Mauze, Yuewei Zhang, James Speck, Mathias Schubert
Department of Electrical and Computer Engineering: Faculty Publications
A set of monoclinic β-(AlxGa1–x)2O3 films coherently grown by plasma-assisted molecular beam epitaxy onto (010)-oriented β-Ga2O3 substrates for compositions x ≤ 0.21 is investigated by generalized spectroscopic ellipsometry at room temperature in the spectral range of 1.5 eV–9.0 eV. We present the composition dependence of the excitonic and band to band transition energy parameters using a previously described eigendielectric summation approach for β-Ga2O3 from the study by Mock et al. All energies shift to a shorter wavelength with the increasing Al content in …
Generalized Ellipsometry On Complex Nanostructures And Low-Symmetry Materials, Alyssa Mock
Generalized Ellipsometry On Complex Nanostructures And Low-Symmetry Materials, Alyssa Mock
Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research
In this thesis, complex anisotropic materials are investigated and characterized by generalized ellipsometry. In recent years, anisotropic materials have gained considerable interest for novel applications in electronic and optoelectronic devices, mostly due to unique properties that originate from reduced crystal symmetry. Examples include white solid-state lighting devices which have become ubiquitous just recently, and the emergence of high-power, high-voltage electronic transistors and switches in all-electric vehicles. The incorporation of single crystalline material with low crystal symmetry into novel device structures requires reconsideration of existing optical characterization approaches. Here, the generalized ellipsometry concept is extended to include applications for materials with …
Tuning The Effective Anisotropy In A Voltage-Susceptible Exchange-Bias Heterosystem, Will Echtenkamp, Mike Street, Ather Mahmood, Christian Binek
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 …
Hysteresis Of Granular Fept:Ag Films With Perpendicular Anisotropy, M. L. Yan, Ralph Skomski, Arti Kashyap, L. Gao, Sy-Hwang Liou, David J. Sellmyer
Hysteresis Of Granular Fept:Ag Films With Perpendicular Anisotropy, M. L. Yan, Ralph Skomski, Arti Kashyap, L. Gao, Sy-Hwang Liou, David J. Sellmyer
Department of Physics and Astronomy: Faculty Publications
Intergranular interactions in nanostructured FePt:Ag thin films and their effect on magnetic hysteresis are investigated. The films, produced by multilayer deposition plus rapid thermal annealing, consist of FePt nanoparticles embedded in a silver matrix. They are investigated by magnetization measurements and magnetic force microscopy. Analytical model calculations, supported by micromagnetic simulations, are used to elucidate the relation between coercivity, hysteresis-loop slope, and spatial correlations during magnetization reversal. The analytical calculations yield simple expressions for the loop slope and the coercivity as a function of the intergranular exchange. Small intergranular exchange enhances the coercivity, but for strong exchange there is a …
Exchange Bias In Fef20-Copt Heterosystems With Perpendicular Anisotropy, Christian Binek
Exchange Bias In Fef20-Copt Heterosystems With Perpendicular Anisotropy, Christian Binek
Christian Binek Publications
The previous exchange bias effect is measured in heterosystems with perpendicular anisotropy consisting of Co/Pt multilayers on top of the (0 0 1) face of a previous FeF2 single crystal. The resulting previous exchange field HE exhibits a strong dependence on temperature and the axial freezing field, HF. Within the framework of an Ising-type model, the HE vs. T as well as the HE vs. HF data are explained in terms of the microscopic spin structure at the interface.
Freezing Field Dependance Of The Exchange Bias In Uniaxial Fef2-Copt Heterosystems With Perpendicular Anisotropy, Christian Binek
Freezing Field Dependance Of The Exchange Bias In Uniaxial Fef2-Copt Heterosystems With Perpendicular Anisotropy, Christian Binek
Christian Binek Publications
The exchange bias effect is measured for the first time in FeF2–CoPt heterosystems with perpendicular anisotropy. The exchange previous field exhibits a strong dependence on the axial previous freezing field. This behavior is explained in terms of the microscopic spin structure at the interface, which is established on cooling to below TN. We calculate the dependence of the spin structure on the previous freezing field within the framework of an Ising model. It takes into account the Zeeman energy as well as an antiferromagnetic exchange coupling between the adjacent layers at the interface.
Magnetoelectric Néel Anisotropies, Ralph Skomski
Magnetoelectric Néel Anisotropies, Ralph Skomski
Ralph Skomski Publications
The applicability of Néel's pair model to metallic 3d surfaces and interfaces is explained in terms of the tight-binding moments theorem. The Néel model reproduces itinerant magnetism so long as the band structure is approximated by third-moment atomic-pair contributions. This establishes an atomic Néel description of interfaces and impurities. The Néel parameter g depends on the d-band filling and, to some extent, on the atomic structure.