A5037934239- Magnetic properties of thin films
- Magnetic Properties and Applications
- Advanced Memory and Neural Computing
- Magneto-Optical Properties and Applications
- Quantum and electron transport phenomena
- Physics of Superconductivity and Magnetism
- Semiconductor materials and devices
- Ferroelectric and Negative Capacitance Devices
- Phase-change materials and chalcogenides
- ZnO doping and properties
- Magnetic and transport properties of perovskites and related materials
- Theoretical and Computational Physics
- Characterization and Applications of Magnetic Nanoparticles
- Advanced Data Storage Technologies
- Magnetic Properties of Alloys
- Neural Networks and Reservoir Computing
- Magnetic Field Sensors Techniques
- Copper Interconnects and Reliability
- Semiconductor Quantum Structures and Devices
- Advancements in Semiconductor Devices and Circuit Design
- Integrated Circuits and Semiconductor Failure Analysis
- Metal and Thin Film Mechanics
- Orbital Angular Momentum in Optics
- Non-Destructive Testing Techniques
- Advanced Electron Microscopy Techniques and Applications
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2016-2025
CEA Grenoble
2016-2025
Spintronique et Technologie des Composants
2016-2025
Universidade Estadual do Maranhão
2025
Centro Universitário UNINOVAFAPI
2025
Universidade Estadual do Piau
2025
Universidade de São Paulo
2025
Universidade Federal do Maranhão
2025
Université Grenoble Alpes
2015-2024
Centre National de la Recherche Scientifique
2015-2024
Ever since the first observation of all-optical switching magnetization in ferrimagnetic alloy GdFeCo using femtosecond laser pulses, there has been significant interest exploiting this process for data-recording applications. In particular, ultrafast speed magnetic reversal can enable writing speeds associated with memory devices to be potentially pushed towards THz frequencies. This work reports development perpendicular tunnel junctions incorporating a stack Tb/Co nanolayers whose...
Magnetic random access memories (MRAMs) are a new non-volatile memory technology trying establish itself as mainstream technology. MRAM cell operation using thermally assisted writing scheme (TA-MRAM) is described in this review well its main design challenges. This approach compared to conventional MRAM, highlighting the improvements write selectivity, power consumption and thermal stability. The TA-MRAM was tested validated dynamic regime down 500 ps pulses. heating process investigated...
Spin tunnel junctions with tunneling magnetoresistance of 36.5%±0.5%, resistance-area product 35±6 kΩ×μm2, and junction area between 6 75 μm2 were fabricated. The barrier height is 2.5±0.3 eV the thickness 7.7±0.3 Å. Large (TMR) values are obtained by vacuum anneal (at temperatures from 100 to 240 °C for over 5 h) prepared as-deposited TMR 21%±1.7%, an 25±6 kΩ×μm2. Two regimes occur during anneal. first one occurs anneals up 200 where resistance increase, but parameters unaltered. second...
An asymmetry in the interfacial anisotropies of Pt/Co and Co/Pt interfaces was observed Pt/Co/Pt sputtered trilayers, anisotropy arising from bottom interface being significantly higher than that top one. Interdiffusion at is believed to be main factor for this asymmetry. It dramatically decreases stack when cobalt layer thinner 1 nm. By introducing ultrathin layers materials immiscible with Co acting as a diffusion barrier interface, effective can doubled low thickness range. This great...
This paper is focused on thermally assisted magnetic random access memories (TA-MRAMs). It explains how the heating produced by Joule dissipation around tunnel barrier of junctions (MTJs) can be used advantageously to assist writing in MRAMs. The main idea apply a pulse junction simultaneously with field (field-induced (TA) switching). Since current also provides spin-transfer torque (current-induced TA switching), lines removed increase storage density TA-MRAMs. Ultimately, induced...
A new approach to increase the downsize scalability of perpendicular STT-MRAM is presented.
We report on the experimental evidence of magnetic helicoidal dichroism, observed in interaction an extreme ultraviolet vortex beam carrying orbital angular momentum with a vortex. Numerical simulations based classical electromagnetic theory show that this dichroism is interference light modes different momenta, which are populated after between and topology. This observation gives insight into interplay magnetism sets framework for development new analytical tools to investigate ultrafast...
Magnetic skyrmions are topological spin textures which envisioned as nanometer scale information carriers in magnetic memory and logic devices. The recent demonstrations of room temperature their current induced manipulation ultrathin films were first steps toward the realization such However, important challenges remain regarding electrical detection low-power nucleation skyrmions, required for read write operations. Here, we demonstrate, using operando microscopy experiments, a single...
We evidence multiple coherent precessional magnetization reversal in microscopic spin valves. Stable, reversible, and highly efficient switching is triggered by transverse field pulses as short 140 ps with energies down to 15 pJ. At high fields a phase found revealing periodic transitions from nonswitching under variation of pulse parameters. the low limit existence relaxation dominated regime established allowing amplitudes below quasistatic threshold.
We demonstrate a quasiballistic switching of the magnetization in microscopic magnetoresistive memory cell. By means time resolved magnetotransport, we follow large angle precession free layer spin valve cell upon application transverse magnetic field pulses. Stopping pulse after $180\ifmmode^\circ\else\textdegree\fi{}$ rotation leads to reversal with times as short 165 ps. This mode represents fundamental ultrafast limit induced reversal.
A thermally assisted writing procedure is proposed in a tunnel junction based magnetic random access memory cell. The layers of the are both exchange-biased with antiferromagnetic layers, reference layer having much higher blocking temperature than storage layer. In operating mode, current pulse sent through generates enough heat to raise above its temperature, without affecting pinning concept demonstrated here for an isolated using homogeneous external field.
We demonstrate that the effective magnetic anisotropy of sputtered (Co/Pt) multilayers can be doubled by limiting interdiffusion occurring at Co/Pt interfaces. present a way to decrease inserting an ultra-thin Cu layer or near When such material is on Co prior Pt deposition, perpendicular anisotropy, as well thermal stability, enhanced for thicknesses smaller than 1 nm. This great interest out-of-plane magnetized spintronic devices which require high down-size scalability reasons together...
This letter presents a study of perpendicular anisotropy in Co/Ni multilayers, which could constitute thick polarizer spin torque oscillators or magnetic electrode tunnel junctions (MTJ) with anisotropy. Perfectly square loops are observed for as-deposited multilayers various sublayer thicknesses and bilayer repetition numbers using Pt buffer layer. An energy 1.0 × 106 erg·cm−3 is obtained 9 nm multilayers. For deposited on MgO, no magnetization component the state, but it develops (even 2.1...
Abstract Hard-axis magnetoresistance loops were measured on perpendicular magnetic tunnel junction pillars of diameter ranging from 50 to 150 nm. By fitting these an analytical model, the effective anisotropy fields in both free and reference layers derived their variations temperature range between 340 K 5 determined. It is found that a second-order term form −K 2 cos 4 θ must be added conventional uniaxial –K 1 explain experimental data. This higher order contribution exists layers. At T =...
In magnetic tunnel junctions (MTJ), synthetic antiferromagnets (SAF) are usually used as reference layer to minimize dipolar interactions induced between this and the free (FL). We show here that use of SAF allows us reduce asymmetry FL reversal due stray fields in nanosized MTJs with perpendicular anisotropy.
Spin-electronics is a very rapidly expanding area of R&D which merges magnetism and electronics (Nobel Prize 2007). Since the discovery giant magnetoresistance in 1988, several breakthroughs have further boosted this field (spin-valves 1990, tunnel 1995, spin transfer 1996, voltage controlled magnetic properties 2004). The phenomenon spin-transfer particularly attractive both from fundamental applied view points. It provides new way to manipulate magnetisation nanostructures by...
Abstract We report here the development of Pt and Pd-free perpendicular magnetic tunnel junctions (p-MTJ) for STT-MRAM applications. start by studying a p-MTJ consisting bottom synthetic Co/Pt reference layer FeCoB/Ru/FeCoB storage covered with an MgO layer. first investigate evolution RKKY coupling Ru spacer thickness in such The becomes antiferromagnetic above 0.5 nm its strength decreases monotonously increasing thickness. This contrasts behavior Co-based systems which maximum interlayer...
This work reports the development of perpendicular magnetic tunnel junctions, based on a multilayered stack [Tb/Co] nanolayers, in which magnetization can be reliably toggled using single optical pulse. The helicity-independent single-shot switching Tb/Co was achieved either 60 fs-long or 5 ps laser pulses with incident fluences down to 4.7 mJ/cm2. for Co-rich composition window multilayer corresponding layer thickness ratios tCo/tTb between 1.3-1.5. confirmed alone as well coupled aCoFeB...
O estudo se concentrou na síntese e caracterização de nanopartículas ouro (AuNPs) estabilizadas no extrato Curcuma longa L., uma planta reconhecida por suas propriedades medicinais, como efeitos anti-inflamatórios antibacterianos. A foi realizada utilizando métodos físico-químicos, incluindo aquecimento em chapa agitação magnética, enquanto a das espectrofotometria UV/VIS, confirmando formação partículas com picos absorção entre 530 560 nm, indicativos tamanhos nanométricos 3 30 nm. Essas...
O objetivo deste artigo é discutir sobre as políticas de segurança pública no Brasil e refletir a reforma do sistema segurança, considerando o contexto histórico em que se deu, implicações para atual Política Nacional Segurança Pública. Trata-se uma revisão integrativa, abordagem qualitativa, exploratório, com fundamento conceito Biopolítica, Foucault. Os dados foram produzidos por meio buscas, conveniência, nas bases SciELO, Scopus Google Scholar, esquematizados da estratégia PICO. Foram...