Jean-Philippe Ansermet

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The aim of the present work is to investigate the nature of spin dependent processes in an organic light emitting diode based on a ITO/α-NPD/Alq3 structure. The electroluminescence time response of the sample is monitored while the OLED is exposed to a high power resonant microwave pulse. Measurements are carried out at room temperature. The time scale of the induced transition is found to be independent of the bias voltage. It is shown, by way of a simulation, that this behavior appears inconsistent with m

The damping of spin waves transmitted through a two-port magnonic device implemented on a yttrium iron garnet thin film is shown to be proportional to the temperature gradient imposed on the device. The sign of the damping depends on the relative orientati ...

The purpose of this introduction to spintronics is to provide some elementary description of its conceptual building blocks. Thus, it is intended for a newcomer to the field. After recalling rudimentary descriptions of spin precession and spin relaxation, spin-dependent transport is treated within the Boltzmann formalism. This suffices to introduce key notions such as the spin asymmetry of the conductivities in the two-current model, the spin diffusion length, and spin accumulation. Two basic mechanisms of

A saddle coil manufactured by electric discharge machining (EDM) from a solid piece of copper has recently been realized at EPFL for Dynamic Nuclear Polarization enhanced Nuclear Magnetic Resonance experiments (DNP-NMR) at 9.4 T. The corresponding electrom ...

A quasi one-dimensional model of spin transport in heterogeneous media based on the Boltzmann equation is presented in order to define the basic properties characterizing perpendicular spin transport in nanostructures. Experimental results are reviewed, first on the giant magnetoresistance of magnetic multilayers: spin dependent scattering in bulk and at interfaces, spin-diffusion length in the ferromagnetic layers and in the non-magnetic spacers. The observations of magnetoresistance associated with spin-s

Spin-dependent transport in granular metallic nanostructures has been investigated by means of a thermoelectric measurement. Cobalt clusters of well-defined size ( = 15 and 600), embedded in copper and silver matrices, show magnetic field responses of u ...

We investigate the ferromagnetic resonance of Co/Cu/Co trilayers by use of AC-spin-transfer torque excitations. Magnetic structures are grown in a 6-mu m-thick commercial nanoporous polycarbonate membranes by use of electrodeposition in a cobalt/copper single bath. We show that microwave magnetic excitations corresponding to the uniform mode of the two cobalt layers are electrically detected as a change of the DC voltage of the system. (C) 2009 Elsevier B.V. All rights reserved.

We present a detailed study of Ta/Ru-based buffers and their influence on features crucial from the point of view of applications of Magnetic Tunnel Junctions (MTJs) such as critical switching current and thermal stability. We study buffer/FeCoB/MgO/Ta/Ru ...

Using pulsed electroluminescence detected magnetic resonance (PELDMR), we study the dynamics of spin processes in Alq(3) based light-emitting diodes. The transitions induced by magnetic resonance are found to be much faster than the space charge reaction t ...

We report on NMR evidence about a novel effect in La1-xCa xMnO3+δ systems with cation deficience. We show that in the low-Ca-doping regime, these systems exhibit a very strong hyperfine field at certain La nuclear sites, which is not present in the stoichiometric compounds. Comparison of our NMR results with recent X-ray absorption data at the Mn K-edge, suggests the formation of a spin-polarized hole arrangement on the 2p oxygen orbitals as the origin of this effect.

The spin transfer torque model applied in the context of a Fokker-Planck analysis (Li and Zhang 2004 Phys. Rev. B 69 134416) is shown to account for a complete set of statistical data for switching times obtained with pseudo spin-valves (Fabian et al 2003 ...

We present magnetodielectric measurements in single crystals of the cubic spin-1/2 compound Cu2OSeO3. A magnetic-field-induced electric polarization (P) and a finite magnetocapacitance (MC) is observed at the onset of the magnetically ordered state (T-c = ...

The template method was used for preparing Zn1-xCoxO nanowires with x ranging from 0.01 to 0.05. Thus, electrochemical deposition was employed for filling up the pores of polycarbonate ion track nanoporous membranes with the desired material. The method al ...

A microwave-compatible lithography-free process is shown to allow the electrical contact of a single nanometric spin valve grown by template synthesis. The complex spin dynamics of a single nanomagnet is revealed by resonant microwave current excitations, ...

CoNiCu/Cu superlattice nanowires have been grown by electrodeposition in nuclear tracketched nanoporous membranes. Transmission electron microscopy (TEM) images show a good layer structure and allow an estimate of the current efficiency. Current perpendicular to plane (CPP) giant magnetoresistance of up to 22%, at ambient temperature, has been measured but appears to be limited by defects, giving rise to ferromagnetic interlayer coupling, at low nonmagnetic layer thicknesses. Magnetic properties of the supe

Yttrium iron garnet (YIG) has been widely used in spin wave studies thanks to its low Gilbert damping constant. However, most high-quality YIG films are grown on gadolinium gallium garnet (GGG) substrate, which makes it difficult to integrate with existing ...

Predicted by the theory, ferromagnetism is expected in Co-doped ZnO. Recently, ferromagnetism above room temperature was reported in thin films as well as in bulk samples made of cobalt-doped zinc oxide. In this study, we report the preparation of ZnO dope ...

We studied the influence of doping HfTe5 with 5% Ti on electric (resistivity and the Hall effect) and thermoelectric transport properties (the Seebeck coefficient, magneto-thermoelectric power, and Nernst effect). The properties of 5% Ti-doped HfTe5 do not ...

Coherent coupling in magnon-based hybrid systems has many potential applications in quantum information processing. Magnons can propagate in magnetically ordered materials without any motion of electrons, offering a unique method to build low-power-consump ...

This paper applies nonequilibrium thermodynamics in the linear regime to describe spin diffusion and magnetoresistance effects and to examine the effect of spin mixing on transport through collinear magnetic layers. To demonstrate the method, it treats ana ...

Jean-Philippe Ansermet

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Pulsed magnetic resonance of Alq3 OLED detected by electroluminescence

Thermal spin torques in magnetic insulators

Spintronics: Conceptual Building Blocks

THz-waves channeling in a monolithic saddle-coil for Dynamic Nuclear Polarization enhanced NMR

Perpendicular Transport of Spin-Polarized Electrons Through Magnetic Nanostructures

Spin-dependent transport in cluster-assembled nanostructures: influence of cluster size and matrix material

Current-driven, electrically detected ferromagnetic resonance in electrodeposited spin valves

Buffer influence on magnetic dead layer, critical current, and thermal stability in magnetic tunnel junctions with perpendicular magnetic anisotropy

Time-resolved spin processes in Alq(3) light-emitting diodes

Spin-polarized oxygen hole states in cation-deficient La 1-xCaxMnO3+δ

Current-induced magnetization switching in pseudo spin-valves

Magnetoelectric effects in single crystals of the cubic ferrimagnetic helimagnet Cu2OSeO3

Preparation and Properties of Cobalt Doped ZnO Nanowires

Microwave spin-torque excitation in a template-synthesized nanomagnet

Superlattice Nanowires

Short-Wavelength Spin Waves in Yttrium Iron Garnet Micro-Channels on Silicon

Ferromagnetism at Room Temperature on Electrodeposited Co2+-Doped ZnO Thin Film

Doping effect on the thermoelectric transport properties of HfTe5

Hybridized Propagation of Spin Waves and Surface Acoustic Waves in a Multiferroic-Ferromagnetic Heterostructure

Thermodynamic description of spin mixing in spin-dependent transport