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Related papers: Superparamagnetic dwell times and tuning of switch…

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We report on room temperature magnetoresistance and low frequency noise in sub-100nm elliptic CoFeB/MgO/CoFeB magnetic tunnel junctions with ultrathin (0.9nm) barriers. For magnetic fields applied along the hard axis, we observe current…

Mesoscale and Nanoscale Physics · Physics 2013-05-28 J. P. Cascales , D. Herranz , J. L. Sambricio , U. Ebels , J. A. Katine , F. G. Aliev

The macroscopic magnetic moment of a superparamagnetic system has to overcome an energy barrier in order to switch its direction. This barrier is formed by magnetic anisotropies in the material and may be surmounted typically after 10^9 to…

Mesoscale and Nanoscale Physics · Physics 2017-09-14 Martin Stier , Alexander Neumann , Andre Kobs , Hans Peter Oepen , Michael Thorwart

We demonstrate a good agreement between mean dwell times measured in 50~nm diameter, perpendicularly magnetized superparamagnetic tunnel junctions (SMTJ), and theoretical predictions based on Langer's theory. Due to a large entropic…

We investigate the dependence of magnetic properties on the post-annealing temperature/time, the thickness of soft ferromagnetic electrode and Ta dusting layer in the pinned electrode as well as their correlation with the tunnel…

We study paramagnetic - ferromagnetic transition due to exchange interaction between classical localized magnetic moments and conduction electrons. We formulate the Dynamical Mean Field Approximation equations for arbitrary electron…

Statistical Mechanics · Physics 2009-11-07 Eugene Kogan , Mark Auslender

We study superconductivity in paramagnetic and ferromagnetically-ordered phases in a two-dimensional electron system with parabolic fermionic dispersion and short-range repulsive interaction. In the paramagnetic phase, we find that a weak…

Superconductivity · Physics 2025-07-11 Zachary M Raines , Andrey V Chubukov

Dwell time for a two state particle tunneling through a noisy thermal magnetic barrier has been calculated by studying the time evolution of the system. The effect of temperature has been included by averaging over the environmental…

Quantum Physics · Physics 2014-02-17 Samyadeb Bhattacharya

Recent results in electric-field control of magnetism have paved the way for the design of alternative magnetic and spintronic devices with enhanced functionalities and low power consumption. Among the diversity of reported magnetoelectric…

The intended use of a magnetic material, from information storage to power conversion, depends crucially on its domain structure, traditionally crafted during materials synthesis. By contrast, we show that an external magnetic field applied…

Materials Science · Physics 2016-09-08 D. M. Silevitch , G. Aeppli , T. F. Rosenbaum

The metamagnetic transition between the antiferromagnetic and paramagnetic state in UIrGe has been studied at various temperatures by magnetization, heat capacity and magnetocaloric-effect measurements on a single crystal in static and…

Creating temperature gradients in magnetic nanostructures has resulted in a new research direction, i.e., the combination of magneto- and thermoelectric effects. Here, we demonstrate the observation of one important effect of this class:…

When fabricating magnetic memories, one of the main challenges is to maintain the bit stability while downscaling. Indeed, for magnetic volumes of a few thousand nm3, the energy barrier between magnetic configurations becomes comparable to…

Materials Science · Physics 2016-05-24 A. Mizrahi , N. Locatelli , R. Lebrun , V. Cros , A. Fukushima , H. Kubota , S. Yuasa , D. Querlioz , J. Grollier

We analyze the effects of the environment on the spin tunneling process of paramagnetic and superparamagnetic particles and conclude that the non assisted macroscopic tunneling rate is hardly affected in such case, but other more effective…

Quantum Physics · Physics 2007-05-23 E. H. Martins Ferreira , M. C. Nemes , H. -D. Pfannes

In magnetic nanostructures one usually uses a magnetic field to commute between two resistance (R) states. A less common but technologically more interesting alternative to achieve R-switching is to use an electrical current, preferably of…

Materials Science · Physics 2009-11-11 J. Ventura , J. P. Araujo , J. B. Sousa , Y. Liu , Z. Zhang , P. P. Freitas

Recent studies have revealed magnetically controllable thermoelectric effects in superconductor/ferromagnet (S/F) structures. A tunable cryogenic thermoelectric generator needs not only a high conversion factor between electricity and heat,…

We have investigated magnetization(M), magnetocaloric effect(MCE) and magnetothermopower(MTEP) in polycrystalline Pr0.6Sr0.4MnO3, which shows a second-order paramagnetic to ferromagnetic transition near room temperature (TC = 305 K).…

Strongly Correlated Electrons · Physics 2012-10-19 D. V. Maheshwar Repaka , T. S. Tripathi , M. Aparnadevi , R. Mahendiran

Exponential and power law temperature dependences are widely used to fit experimental data of magnetic relaxation time in single molecular magnets. We derived a theory to show how these rules arise from the underling relaxation mechanisms…

Mesoscale and Nanoscale Physics · Physics 2020-09-16 Lei Gu , Ruqian Wu

Antiferromagnetic materials hold promising prospects in novel types of spintronics applications. Assessing the stability of antiferromagnetic nanostructures against thermal excitations is a crucial aspect of designing devices with a high…

Mesoscale and Nanoscale Physics · Physics 2019-08-28 Levente Rózsa , Severin Selzer , Tobias Birk , Unai Atxitia , Ulrich Nowak

Perpendicularly magnetized CoFeB layers with ultra-thin non-magnetic insertion layers are very widely used as the electrodes in magnetic tunnel junctions for spin transfer magnetic random access memory devices. Exchange interactions play a…

Mesoscale and Nanoscale Physics · Physics 2019-10-25 Jamileh Beik Mohammadi , Bartek Kardasz , Georg Wolf , Yizhang Chen , Mustafa Pinarbasi , Andrew D. Kent

We study the tunneling magneto thermo power (TMTP) in CoFeB/MgO/CoFeB magnetic tunnel junction nanopillars. Thermal gradients across the junctions are generated by a micropatterned electric heater line. Thermo power voltages up to a few…

Materials Science · Physics 2012-09-13 N. Liebing , S. Serrano-Guisan , K. Rott , G. Reiss , J. Langer , B. Ocker , H. W. Schumacher
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