Modelling and design tools were developed in the frame of HYMAGINE to cover both the fundamental and design aspects of the project. Concerning the fundamental aspects, we developed a code allowing to calculate both the transport properties and the magnetization dynamics in systems of complex geometry wherein the current can be expected to be non-uniform […]

Olivier Fruchart,-, Bernard Diény We calculate the magnetostatic energy of synthetic ferrimagnet (SyF) elements, consisting of two thin ferromagnetic layers coupled antiferromagnetically, e.g. through RKKY coupling. Uniform magnetization is assumed in each layer. Exact formulas as well as approximate yet accurate ones are provided. These may be used to evaluate various quantities of SyF such […]

B Dieny In 2010, the International Technology Roadmap for Semiconductors (ITRS) published an assessment of the potential and maturity of selected emerging research on memory technologies. Eight different technologies of non-volatile memories were compared (ferroelectric gate field- effect transistor, nano-electro-mechanical switch, spin-transfer torque random access memories (STTRAM), various types of resistive RAM, in particular redox […]

Yue Zhang , Weisheng Zhao , Guillaume Prenat , Thibaut Devolder , Jacques-Olivier Klein , Claude Chappert , Bernard Dieny , and Dafiné Ravelosona Magnetic tunnel junctions (MTJ) are considered as one of the most promising candidates for the next generation of nonvolatile memories and programmable logic chips. Spin transfer torque (STT) in CoFeB/MgO/CoFeB MTJs […]

S. Leulmi, H. Joisten, T. Dietsch, C. Iss, M. Morcrette, S. Auffret, P. Sabon, and B. Dieny Magnetic nanoparticles are receiving an increasing interest for various biotechnological applications due to the capability that they offer to exert actuation on biological species via external magnetic fields. In this study, two types of magnetic particles recently proposed […]

We propose a model that describes current-in-plane tunneling transport in double barrier magnetic tunnel junctions in diffusive regime. Our study shows that specific features appear in double junctions that are described by introducing two typical length scales. The model may be used to measure the magnetoresistance and the resistance area product of both barriers in […]

1 Introduction 2 Magnetic Tunnel Junctions: A Route for CMOS/Magnetism Integration 3 Spin-Transfer Phenomenon 4 Magnetic Random Access Memories (MRAM) 4.1 Stoner-Wolfarth MRAM (SW-MRAM) 4.2 Toggle MRAM 4.3 Spin-Transfer Torque MRAM (STT-MRAM) 4.4 Thermally Assisted MRAM (TA-MRAM) 5 Racetrack Memories

I.L. Prejbeanu, R.C. Sousa, B. Dieny, J.-P. Nozieres, S. Bandiera, K. Mackay On paper, MRAMs combine non volatility, high speed, moderate power consumption, infinite endurance and radiation hardness, all at low cost and easy to embed. Since its inception in the late 90’s, however, and despite numerous promising announcements from laboratories, large corporations and start-ups, […]

A. Mejdoubi, G. Prenat, and B. Dieny Magnetic Tunnel Junction (MTJ) devices are CMOS compatible with high stability, high reliability and non-volatility. A macro-model of MTJ with precessional switching is presented in this paper. This model is based on Spin-Transfer Torque (STT) writing approach. The current-induced magnetic switching and excitations was studied in structures comprising […]

Spinelectronics is a very rapidly expanding area of R&D which merges magnetism and electronics (Nobel Prize 2007). Since the discovery of giant magneto-resistance (GMR) in 1988, several breakthroughs have further boosted this field [spin-valves 1990, tunnel magneto-resistance (TMR) 1995, spin-transfer 1996, voltage controlled magnetic properties 2004]. The phenomenon of spin-transfer is particularly attractive both from […]