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Full-Text Articles in Physics
Giant Enhancement Of Magnetic Anisotropy In Ultrathin Manganite Films Via Nanoscale 1d Periodic Depth Modulation, Anil Rajapitamahuni, L. Zhang, Mark A. Koten, V. R. Singh, John D. Burton, Evgeny Y. Tsymbal, Jeffrey E. Shield, Xia Hong
Giant Enhancement Of Magnetic Anisotropy In Ultrathin Manganite Films Via Nanoscale 1d Periodic Depth Modulation, Anil Rajapitamahuni, L. Zhang, Mark A. Koten, V. R. Singh, John D. Burton, Evgeny Y. Tsymbal, Jeffrey E. Shield, Xia Hong
Evgeny Tsymbal Publications
The relatively low magnetocrystalline anisotropy (MCA) in strongly correlated manganites (La,Sr)MnO3 has been a major hurdle for implementing them in spintronic applications. Here we report an unusual, giant enhancement of in-plane MCA in 6 nm La0.67Sr0.33MnO3 (LSMO) films grown on (001) SrTiO3 substrates when the top 2 nm is patterned into periodic stripes of 100 or 200 nm width. Planar Hall effect measurements reveal an emergent uniaxial anisotropy superimposed on one of the original biaxial easy axes for unpatterned LSMO along (110) directions, with a 50-fold enhanced anisotropy energy density of 5.6 × …
On The Structural Origin Of The Single-Ion Magnetic Anisotropy In Lufeo3, Shi Cao, Xiaozhe Zhang, Tula R. Paudel, Kishan Sinha, Xiao Wang, Xuanyuan Jiang, Wenbin Wang, Stuart Brutsche, Jian Wang, Philip J. Ryan, Jong-Woo Kim, Xuemei Cheng, Evgeny Y. Tsymbal, Peter A. Dowben, Xiaoshan Xu
On The Structural Origin Of The Single-Ion Magnetic Anisotropy In Lufeo3, Shi Cao, Xiaozhe Zhang, Tula R. Paudel, Kishan Sinha, Xiao Wang, Xuanyuan Jiang, Wenbin Wang, Stuart Brutsche, Jian Wang, Philip J. Ryan, Jong-Woo Kim, Xuemei Cheng, Evgeny Y. Tsymbal, Peter A. Dowben, Xiaoshan Xu
Evgeny Tsymbal Publications
Electronic structures for the conduction bands of both hexagonal and orthorhombic LuFeO3 thin films have been measured using x-ray absorption spectroscopy at oxygen K (O K) edge. Dramatic differences in both the spectra shape and the linear dichroism are observed. These differences in the spectra can be explained using the differences in crystal field splitting of the metal (Fe and Lu) electronic states and the differences in O 2p-Fe 3d and O 2p-Lu 5d hybridizations. While the oxidation states has not changed, the spectra are sensitive to the changes in the local environments of the Fe3+ and Lu …
Engineering Interfacial Energy Profile By Changing The Substrate Terminating Plane In Perovskite Heterointerfaces, S. Roy, Alim Solmaz, John D. Burton, Mark Huijben, Guus Rijnders, Evgeny Y. Tsymbal, T. Banerjee
Engineering Interfacial Energy Profile By Changing The Substrate Terminating Plane In Perovskite Heterointerfaces, S. Roy, Alim Solmaz, John D. Burton, Mark Huijben, Guus Rijnders, Evgeny Y. Tsymbal, T. Banerjee
Evgeny Tsymbal Publications
Atomically engineered oxide heterointerfaces show a range of novel phenomena not present in their bulk form, thus providing an additional knob to tune the functional properties across such interfaces. Here we show that for an oxide Schottky interface between metallic SrRuO3 and semiconducting Nb doped SrTiO3 (Nb:STO) the terminating surface of the substrate plays a crucial role in determining the electronic transport across it. Interestingly this is achieved by engineering a monolayer of a charge-neutral SrO layer across the Schottky interface and not by the insertion of charged layers at the interface, as has been demonstrated earlier. These …
Modification Of The G-Phonon Mode Of Graphene By Nitrogen Doping, Pavel V. Lukashev, Liuyan Zhao, Tula R. Paudel, Theanne Schiros, Noah Hurley, Evgeny Y. Tsymbal, Aron Pinczuk, Abhay Pasupathy, Rui He
Modification Of The G-Phonon Mode Of Graphene By Nitrogen Doping, Pavel V. Lukashev, Liuyan Zhao, Tula R. Paudel, Theanne Schiros, Noah Hurley, Evgeny Y. Tsymbal, Aron Pinczuk, Abhay Pasupathy, Rui He
Evgeny Tsymbal Publications
The effect of nitrogen doping on the phonon spectra of graphene is analyzed. In particular, we employ first-principles calculations and scanning Raman analysis to investigate the dependence of phonon frequencies in graphene on the concentration of nitrogen dopants. We demonstrate that the G phonon frequency shows oscillatory behavior as a function of nitrogen concentration. We analyze different mechanisms which could potentially be responsible for this behavior, such as Friedel charge oscillations around the localized nitrogen impurity atom, the bond length change between nitrogen impurity and its nearest neighbor carbon atoms, and the long-range interactions of the nitrogen point defects. We …
Tunneling Anisotropic Magnetoresistance In A Magnetic Tunnel Junction With Half-Metallic Electrodes, John D. Burton, Evgeny Y. Tsymbal
Tunneling Anisotropic Magnetoresistance In A Magnetic Tunnel Junction With Half-Metallic Electrodes, John D. Burton, Evgeny Y. Tsymbal
Evgeny Tsymbal Publications
Tunneling anisotropic magnetoresistance (TAMR) is the difference in resistance of a magnetic tunnel junction due to a change in magnetization direction of one or both magnetic electrodes with respect to the flow of current. We present the results of first-principles density functional calculations of the TAMR effect in magnetic tunnel junctions with La0.7Sr0.3MnO3 (LSMO) electrodes and a SrTiO3 (STO) tunneling barrier. We find an ∼500% difference in resistance between magnetization in the plane and out of the plane. This large TAMR effect originates from the half-metallic nature of LSMO: When magnetization is out of …
Electronic Structure And Stability Of The Ch3Nh3Pbbr3 (001) Surface, Xin Huang, Tula R. Paudel, Peter A. Dowben, Shuai Dong, Evgeny Y. Tsymbal
Electronic Structure And Stability Of The Ch3Nh3Pbbr3 (001) Surface, Xin Huang, Tula R. Paudel, Peter A. Dowben, Shuai Dong, Evgeny Y. Tsymbal
Evgeny Tsymbal Publications
The energetics and the electronic structure of methylammonium lead bromine (CH3NH3PbBr3) perovskite (001) surfaces are studied based on density functional theory. By examining the surface grand potential, we predict that the CH3NH3Br-terminated (001) surface is energetically more favorable than the PbBr2-terminated (001) surface, under thermodynamic equilibrium conditions of bulk CH3NH3PbBr3. The electronic structure of each of these two different surface terminations retains some of the characteristics of the bulk, while new surface states are found near band edges which may affect the …
Band Structure And Spin Texture Of Bi2Se3 3D Ferromagnetic Metal Interface, Jia Zhang, Julian P. Velev, Xiaoqian Dang, Evgeny Y. Tsymbal
Band Structure And Spin Texture Of Bi2Se3 3D Ferromagnetic Metal Interface, Jia Zhang, Julian P. Velev, Xiaoqian Dang, Evgeny Y. Tsymbal
Evgeny Tsymbal Publications
The spin-helical surface states in a three-dimensional topological insulator (TI), such as Bi2Se3, are predicted to have superior efficiency in converting charge current into spin polarization. This property is said to be responsible for the giant spin-orbit torques observed in ferromagnetic metal/TI structures. In this work, using first-principles and model tight-binding calculations, we investigate the interface between the topological insulator Bi2Se3 and 3d-transition ferromagnetic metals Ni and Co. We find that the difference in the work functions of the topological insulator and the ferromagnetic metals shift the topological surface states down about 0.5 …
Enhanced Tunneling Electroresistance In Ferroelectric Tunnel Junctions Due To The Reversible Metallization Of The Barrier, Xiaohui Liu, J. D. Burton, Evgeny Y. Tsymbal
Enhanced Tunneling Electroresistance In Ferroelectric Tunnel Junctions Due To The Reversible Metallization Of The Barrier, Xiaohui Liu, J. D. Burton, Evgeny Y. Tsymbal
Evgeny Tsymbal Publications
Realizing a large tunneling electroresistance (TER) effect is crucial for device application of ferroelectric tunnel junctions (FTJs). FTJs are typically composed of a thin ferroelectric layer sandwiched by two metallic electrodes, where TER generally results from the dependence of the effective tunneling barrier height on the ferroelectric polarization. Since the resistance depends exponentially not only on barrier height but also on barrier width, TER is expected to be greatly enhanced when one of the electrodes is a semiconductor where the depletion region near the interface can be controlled via ferroelectric polarization. To explore this possibility, we perform studies of SrRuO …