By adding Fe 3 O 4 nanoparticles into the PVDF barrier, we found that the ferroelectric properties of the OMFTJ are considerably improved compared to those with a pure PVDF barrier. We fabricate ferroelectric tunnel junctions with a La 0.7 Sr 0.3 MnO 3 bottom electrode and BaTiO 3 ferroelectric barrier. One of the technologies for such applications is ferroelectric random access memories, where information is stored as ferroelectric polarization. tel-01382194 Un memristor est une nanorésistance variable non-volatile dont la valeur dépend de la quantité de charges qui l'a traversée. Ferroelectric and multiferroic tunnel junctions - Volume 37 Issue 2 - E.Y. The thickness of the ferroelectric layer is small enough to allow tunneling of electrons. Ferroelectric tunnel junctions : from electronics to spintronics. Ferroelectric Tunnel Junctions for Linear Computation Large memristor-based neural networks in hardware require low current operation while maintaining computational linearity. Buchal Prof. Dr. M. Braden Tag der mündlichn Prüfung: 10. Such ferroelectric memristors can be used as artificial synapses in neuromorphic architectures. 10.3.1).By application of an electric field across the stack, polarization reversal occurs, and this leads to modulation of the barrier height in the ferroelectric layer. Materials Science [cond-mat.mtrl-sci]. Polar-ization switching of the ferroelectric barrier in a FTJ results in a change of the tunneling conductance, which is known as the tunnel electroresistance (TER) effect. This phenomenon has been observed in several systems, such as BaTiO 3 [6–8], Pb(Zr 0.2Ti 0.8)O 3 [9], PbTiO 3 [10], and BiFeO 3 [11,12]. Oxide-based resistive switching devices, including ferroelectric tunnel junctions and resistance random access memory, are promising candidates for the next-generation non-volatile memory technology. Ferroelectric tunnel junctions (FTJs) have been intensively studied in recent years due to the great potential in nonvolatile memory devices and two-dimensional (2D) FTJs have started to catch attention lately because of their atomic thickness and their significance in miniaturizing FTJ device sizes. Theoretical current-voltage characteristics of ferroelectric tunnel junctions H. Kohlstedt,1 N. A. Pertsev,1,2 J. Rodríguez Contreras,1 and R. Waser1,3 1Institut für Festkörperforschung and CNI, Forschungszentrum Jülich, D-52425 Jülich, Germany 2A. Ferroelectric tunnel junctions (FTJs), composed of two metal electrodes separated by an ultrathin ferroelectric barrier, have attracted much attention as promising candidates for non-volatile resistive memories. Computer memory that is non-volatile and therefore able to retain its information even when switched off enables computers that do not need to be booted up. In particular, the electric-field-induced polarization reversal creates the giant electroresistance (GER) effect. Durant ce travail de thèse, nous avons étudié deux concepts originaux de memristor fondés sur des effets purement électroniques. (E gap is the energy gap. conductance of ferroelectric tunnel junctions (FTJs) due to the polarization of the ferroelectric material. 3. A ferroelectric tunnel junction (FTJ) is a two-terminal, nonvolatile memory composed of a thin ferroelectric layer sandwiched between conductive metal electrodes (Fig. Ferroelectric tunnel junctions : memristors for neuromorphic computing. Ferroelectric tunnel junctions for electronics an spintronics. English. ties for ferroelectric tunnel junctions (FTJs) [2–5]. out-of plane H. Kohlstedt, N. A. Pertsev, and R. Waser, in J Rodríguez Contreras et al ,, , Ferroelectric Thin Films X, MRS Symposia Proceedings, 688, 161 (2002). Atelier spintronique. So far, almost all FTJs studied focus on adopting three dimensional (3D) ferroelectric materials as the tunnel barrier. NNT : 2016SACLS089 . Coupled to magnetic electrodes, the resulting multiferroic tunnel junctions enable a non-volatile control of magnetism at the ferroelectric/electrode interface and of the spin-polarized current associated. We use poling strategies to promote the generation and transport of oxygen vacancies at the metallic top electrode. Ferroelectric materials are characterized by spontaneous electric polarization that can be switched between (at least) two stable orientations by applying an external electric fi eld. Sören Boyn. However, the interfacial effect regarding the metallic electrodes on tunneling electroresistance (TER) has still remained unclear in traditional FTJs. Abstract: Ferroelectric memories have made big advancements in the last years due to the discovery of ferroelectricity in already widely used hafnium oxide. In this work, we propose a ferroionic tunnel junction to realize a giant electroresistance. Université Paris Saclay (COmUE), 2016. ferroelectric tunnel junctions (FTJ) Mohammad Abuwasib1*, Hyungwoo Lee2, Chang-Beom Eom2, Alexei Gruverman3, Jonathan Bird 1 and Uttam Singisetti 1 1Electrical Engineering, University at Buffalo (SUNY), Buffalo. Recent Work on Ferroelectric Tunnel Junctions Nanoscale polarization manipulation and conductance switching in ultrathin filmsof a ferroelectric copolymer Hongwei QuHongwei Qu,et al APLet al., APL 82 4322 (2003)4322 (2003). Theoretical and experimental works have revealed that the tunnelling resistance switching in FTJs originates mainly from a ferroelectric modulation on the barrier height. Here we investigate ferroelectric tunnel junctions (FTJ) consisting of a ferroelectric hafnium zirconium oxide layer and a dielectric aluminum oxide layer. Ferroelectric tunnel junctions (FTJs), composed of two metal electrodes separated by an ultrathin ferroelectric barrier, have attracted much attention as promising candidates for non-volatile resistive memories. Ferroelectric tunnel junctions (FTJs) continue to draw tremendous interest due to their applications in non-volatile data storage devices. Usually a FTJ is composed of a few nanometer thick ferroelectric films sandwiched between two metal electrodes, where electronic transport is domi-nated by tunneling. Their energy-efficient hardware implementations will greatly benefit from nanodevices, called memristors, whose small size could enable the high synaptic connectivity degree observed in the brain.In this work, we concentrate on memristors based on ferroelectric tunnel junctions that are composed of an ultrathin ferroelectric film between two metallic electrodes. the performance of ferroelectric tunnel junctions A Dörfler1, 2, G Kolhatkar , U Wagner2 and A Ruediger 1 1 INRS-EMT, 1650 Blvd. Ferroelectric tunnel junctions (FTJs) have recently aroused significant interest due to their fascinating properties useful for applications in nanoelectronics, spintronics and data sto-rage [1–3]. This behavior is demonstrated to enable a robust spike-timing-dependent plasticity-type … a tunnel junction is known as a ferroelectric tunnel junction (FTJ) 20 and is schematically depicted in Figure 1b . Ferroelectric tunnel junctions (FTJs) composed by sandwiching a thin ferroelectric layer between two leads have attracted great interest for their potential applications in nonvolatile memories due to the tunnel electroresistance (TER) effect. of a tunnel junction with a ferroelectric barrier. par Vincent Garcia, Unité mixte THALES - CNRSVincent Garcia, Unité mixte THALES - CNRS A ferroelectric tunnel junction. Generated oxygen vacancies control the stability of the ferroelectric polarization and modify its coercive fields. We report on the fabrication of an organic multiferroic tunnel junction (OMFTJ) based on an organic barrier of the Poly(vinylidene fluoride) (PVDF):Fe 3 O 4 nanocomposite. Enhanced tunneling electroresistance in FTJ can be achieved by asymmetric electrodes or introducing metal-insulator transition interlayers. In multiferroic tunnel junctions (MFTJs), spin-dependent tunneling can be controlled by reversing the electric polarization and vice versa. Ferroelectric tunnel junction memristors, biased by trivial logarithmic amplifiers, provide a … The ability to change states using voltage in ferroelectric tunnel junctions (FTJs) offers a route for lowering the switching energy of memories. Recently, ferroelectric tunnel junctions (FTJs) have attracted considerable attention for potential applications in next‐generation memories, owing to attractive advantages such as high‐density of data storage, nondestructive readout, fast write/read access, and low energy consumption. A new compact model for HfO2-based ferroelectric tunnel junction (FTJ) memristors is constructed based on detailed physical modeling using calibrated TCAD simulations. E F is the Fermi energy, V is the applied voltage, V c is the coercive voltage, t is the barrier thickness, and δt is the thickness variation under an applied field. Computer memory based on ferroelectric polarization is a promising alternative to technologies based, for example, on magnetism. Ferroelectric Tunnel Junctions I n a u g u r a l – D i s s e r t a t i o n zur Erlangung des Doktorgrades der Mathematisch-Naturwissenschaftlichen Fakultät der Universität zu Köln vorgelegt von Julio Rodríguez Contreras aus Hürth Eigenverlag Forschungszentrum Jülich, Jülich, 2004 . Physics and Astronomy, University of Nebraska, Lincoln *mabuwasi@buffalo.edu. Theoretical and experimental works have revealed that the tunnelling resistance switching in FTJs originates mainly from a ferroelectric modulation on the barrier height. Berichterstatter: Prof. Dr. Ch. 2. Tsymbal, A. Gruverman, V. Garcia, M. Bibes, A. Barthélémy Another idea of recent interest is the ferroelectric tunnel junction (FTJ) in which a contact is made up by nanometer-thick ferroelectric film placed between metal electrodes. A typical FTJ consists of two metal electrodes separated by a nanometer-thick ferroelectric barrier layer, which allows electron tunneling through it. Owing to a reversible electric polarization, FTJs are expected to have current-voltage character-istics different from those of conventional tun-nel junctions. A multi-domain configuration of the ferroelectric material is demonstrated to produce quasi-continuous conductance of the FTJ. Ferroelectric tunnel junctions (FTJs) have recently aroused extensive attention for applications in information storage. Materials Science and Engineering, University of Wisconsin, Madison. Schematic diagram of a tunnel junction, which consists of two electrodes separated by a nanometer-thick ferroelectric barrier layer. Studies of ferroelectric tunnel junctions (FTJs) have risen due to the promise of applications as electronic devices [1–3]. Achieved by asymmetric electrodes or introducing metal-insulator transition interlayers by asymmetric electrodes or introducing metal-insulator transition interlayers to tunneling. 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