Structural characterization and magnetic profile of annealed CoFeB/MgO multilayers (2009)
M. Vadalá, K. Zhernenkov, M. Wolff, B.P. Toperverg, K. Westerholt, ...
Journal article
MICROSYSTEM FOR BIOLOGICAL ANALYSIS BASED ON MAGNETORESISTIVE SENSING (2008)
J. Germano, M. S. Piedade, L. Sousa, T. M. Almeida, P. Lopes, F. A. Cardoso, ...
Abstract: This paper presents a microsystem for biomolecular recognition (DNA, enzymes) based on a biochip, which uses magnetic field arraying of magnetically tagged biomolecules and high sensitivity...
Ventura, J., Zhang, Z., Liu, Y., Sousa, J. B., Freitas, P. P.
Current Induced Resistance Switching (CIS) was recently observed in thin tunnel junctions (TJs) with ferromagnetic (FM) electrodes and attributed to electromigration of metallic atoms in...
Overcoming the Dipolar Disorder in Dense CoFe Nanoparticle Ensembles: Superferromagnetism (2007)
Bedanta, S., Eimüller, T., Kleemann, W., Rhensius, J., Stromberg, F., Amaladass, E., ...
Quasi ballistic magnetization reversal (2006)
Schumacher, H. W., Chappert, C., Sousa, R. C., Freitas, P. P., Miltat, J.
We demonstrate a quasi ballistic switching of the magnetization in a microscopic mag-neto resistive memory cell. By means of time resolved magneto transport we follow the large angle precession of...
Phase Coherent Precessional Magnetization Reversal in Micro-scopic Spin Valve Elements (2006)
Schumacher, H. W., Chappert, C., Crozat, P., Sousa, R. C., Freitas, P. P., Miltat, J., ...
We study the precessional switching of the magnetization in microscopic spin valve cells induced by ultra short in-plane hard axis magnetic field pulses. Stable and highly efficient switching is...
Ventura, J., Ferreira, R., Sousa, J. B., Freitas, P. P.
Magnetic tunnel junctions (MTJs) with partially oxidized 9 \AA AlO$_x$-barriers were recently shown to have the necessary characteristics to be used as magnetoresistive sensors in high-density...
Nanoscopic processes of Current Induced Switching in thin tunnel junctions (2006)
Ventura, J., Araujo, J. P., Sousa, J. B., Liu, Y., Zhang, Z., Freitas, P. P.
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...
Modulated magnetization depth profile in dipolarly coupled magnetic multilayers (2006)
Bedanta, S., Kentzinger, E., Petracic, O., Kleemann, W., Rücker, U., Brückel, T., ...
This version is available at the following Publisher URL: http://prb.aps.org
Collective states of interacting ferromagnetic nanoparticles (2005)
Petracic, O., Chen, X., Bedanta, S., Kleemann, W., Sahoo, S., Cardoso, S., ...
Discontinuous magnetic multilayers [CoFe/Al2O3] are studied by use of magnetometry, susceptometry and numeric simulations. Soft ferromagnetic Co80Fe20 nanoparticles are embedded in a diamagnetic...
Domain imaging, MOKE and magnetoresistance studies of CoFeB films for MRAM applications (2005)
Teixeira, J. M., Silva, R. F. A., Ventura, J., Pereira, A. M., Carpinteiro, F., Araujo, J. P., ...
We present a detailed study on domain imaging, Kerr effect magnetometry (MOKE) and magnetoresistance (MR), for a series of 20 nm Co$_{73.8}$Fe$_{16.2}$B$_{10}$ thin films, both as-deposited...
Anomalous magnetoresistance behavior of CoFe nano-oxide spin valves at low temperatures (2005)
Ventura, J., Sousa, J. B., Freitas, P. P., Veloso, A.
We report magnetoresistance curves of CoFe nano-oxide specular spin valves of MnIr/CoFe/nano-oxidized CoFe/CoFe/Cu/CoFe/nano-oxidized CoFe/Ta at different temperatures from 300 to 20 K. We extend the...
Ventura, J., Sousa, J. B., Liu, Y., Zhang, Z., Freitas, P. P.
Current Induced Resistance Switching (CIS) was recently observed in thin tunnel junctions with ferromagnetic (FM) electrodes \emph{i.e} FM/I/FM. This effect was attributed to electromigration of...
Tunnel Barrier Fabrication on Si and its impact on a spin transistor (2005)
Dennis, C L, Tiusan, C V, Ferreira, R A, Gregg, J F, Ensell, G J, Thompson, S M, ...
The realization of many future spintronic devices requires efficient spin injection into semiconductor structures. Critical considerations include interfacial intermixing of the metallic components...
Tunnel Barrier Fabrication on Si and its impact on a spin transistor (2005)
Dennis, C L, Tiusan, C V, Ferreira, R A, Gregg, J F, Ensell, G J, Thompson, S M, ...
The realization of many future spintronic devices requires efficient spin injection into semiconductor structures. Critical considerations include interfacial intermixing of the metallic components...
Tunnel Barrier Fabrication on Si and its impact on a spin transistor (2005)
Dennis, C L, Tiusan, C V, Ferreira, R A, Gregg, J F, Ensell, G J, Thompson, S M, ...
The realization of many future spintronic devices requires efficient spin injection into semiconductor structures. Critical considerations include interfacial intermixing of the metallic components...
Tunnel Barrier Fabrication on Si and its impact on a spin transistor (2005)
Dennis, C L, Tiusan, C V, Ferreira, R A, Gregg, J F, Ensell, G J, Thompson, S M, ...
The realization of many future spintronic devices requires efficient spin injection into semiconductor structures. Critical considerations include interfacial intermixing of the metallic components...
Superferromagnetic domain state of a discontinuous metal insulator multilayer (2005)
Bedanta, S., Petracic, O., Kentzinger, E., Kleemann, W., Rücker, U., Paul, A., ...
This version is available at the following Publisher URL: http://prb.aps.org
Tunnel Barrier Fabrication on Si and its impact on a spin transistor (2005)
Dennis, C L, Tiusan, C V, Ferreira, R A, Gregg, J F, Ensell, G J, Thompson, S M, ...
The realization of many future spintronic devices requires efficient spin injection into semiconductor structures. Critical considerations include interfacial intermixing of the metallic components...
Tunnel Barrier Fabrication on Si and its impact on a spin transistor (2005)
Dennis, C L, Tiusan, C V, Ferreira, R A, Gregg, J F, Ensell, G J, Thompson, S M, ...
The realization of many future spintronic devices requires efficient spin injection into semiconductor structures. Critical considerations include interfacial intermixing of the metallic components...
Ferromagnetic coupling field reduction in CoFeB tunnel junctions deposited by ion beam (2004)
Cardoso, S., Ferreira, R., Freitas, P.P., MacKenzie, M., Chapman, J.N., Ventura, J.O., ...
In this paper, junctions with reduced H-f coupling were fabricated by ion beam deposition and oxidation, using CoFeB electrodes. The CoFeB layer has a strong (111) texture that can be the origin of...
Cole-Cole Analysis of the Superspin Glass System Co80Fe20/Al2O3 (2003)
Petracic, O., Sahoo, S., Binek, Christian, Kleemann, W., Sousa, J.B., Cardoso, S., ...
Ac susceptibility measurements were performed on discontinuous magnetic multi-layers [Co80Fe20 (t)/Al2O3 (3 nm)] 10, t = 0.9 and 1.0 nm, by Superconducting Quantum Interference Device (SQUID)...
Magnetic relaxation phenomena in the superspin-glass system [Co80Fe20/Al2O3]10 (2002)
Sahoo, S., Petracic, O., Binek, Christian, Kleemann, W., Sousa, J. B., Cardoso, S., ...
Relaxation and temperature cycles of thermoremanent magnetization, MTRM, in the superspin-glass phase of [Co80Fe20 (0.9 nm)/Al2O3 (3 nm)] 10 have been investigated. The relaxation of MTRM exhibits...
Chen, X., Sichelschmidt, O., Kleeman, W., Binek, Christian, Sousa, J.B., Cardoso, S., ...
The ac susceptibility of a superferromagnetic discontinuous multilayer [Co80Fe20(1.4 nm)/ Al2O3(3 nm)]10 is measured as a function of temperature, frequency, and field amplitude and...
Quasi ballistic magnetization reversal (2002)
Schumacher, H. W., Chappert, C., Sousa, R. C., Freitas, P. P., Miltat, J.
We demonstrate a quasi ballistic switching of the magnetization in a microscopic mag-neto resistive memory cell. By means of time resolved magneto transport we follow the large angle precession of...
Phase Coherent Precessional Magnetization Reversal in Micro-scopic Spin Valve Elements (2002)
Schumacher, H. W., Chappert, C., Crozat, P., Sousa, R. C., Freitas, P. P., Miltat, J., ...
We study the precessional switching of the magnetization in microscopic spin valve cells induced by ultra short in-plane hard axis magnetic field pulses. Stable and highly efficient switching is...
Cole-Cole analysis of the superspin glass system Co80Fe20/Al2O3 (2002)
Petracic, O., Sahoo, S., Binek, Ch., Kleemann, W., Sousa, J. B., Cardoso, S., ...
Ac susceptibility measurements were performed on discontinuous magnetic multilayers [Co80Fe20(t)/Al2O3(3nm)]x10, t = 0.9 and 1.0nm, by Superconducting Quantum Interference Device (SQUID)...
Superspin-glass nature of discontinuous Co80Fe20/Al2O3 multilayers (2002)
Sahoo, S., Petracic, O., Binek, Christian, Kleeman, W., Sousa, J.B., Cardoso, S., ...
Ferromagnetic single domain particles of CoFe in discontinuous magnetic multilayers [Co80Fe20 (0.9 nm)/ Al2O3(3 nm)] 10 reveal spin-glass ordering below Tg=43.6 K as evidenced by the criticality of...
Characterization of nano-oxide layers fabricated by ion beam oxidation (2002)
Cardoso, Susana, Zongzhi Zhang, Haohua Li, Ferreira, R., Freitas, P. P., Peng Wei, ...
In this paper, a remote O2 ion source is used for the formation of nano-oxide layers. The oxidation efficiency was measured in CoFe-oxide films, and a decrease of the oxide layer with the pan angle...
Magnetic states of granular layered CoFe-Al2O3 (2001)
Sousa, J.B., Kakazei, G.N., Pogorelov, Y.G., Santos, J.A.M., Petracic, O., Kleeman, W.W., ...
The granular layered magnetic system Co80Fe20(t)/Al2 O3 (3 nm), where the Co80Fe20 layers of nominal thickness t form separate, almost spherical magnetic granules of typical diameter 2-3 nm between...
Exchange enhancement and thermal anneal in Mn/sub 76/Ir/sub 24/ bottom-pinned spin valves (2001)
Haohua, L., Freitas, P.P., Zhenjun, W., Sousa, J.B., Gogol, P., Chapman, J.N.
Exchange enhancement through thermal anneal in bottom-pinned Mn/sub 76/Ir/sub 24/ spin valves is investigated. Samples were fabricated by ion beam deposition (IBD), post-annealed in vacuum (10/sup...
Kleeman, W., Petracic, O., Binek, Christian, Kakazei, G.N., Pogorelov, Yu. G., Sousa, J.B., ...
Dipolar superferromagnetism with reentrant low-temperature superspin glass behavior is observed on a randomly distributed ferromagnetic nanoparticle systems in discontinuous metal-insulator...
Exchange enhancement and thermal anneal in Mn/sub 76/Ir/sub 24/ bottom-pinned spin valves
Haohua, Li, Freitas, P.P., Zhenjun, Wang, Sousa, J.B., Gogol, P., Chapman, J.
Exchange enhancement through thermal anneal in bottom-pinned Mn/sub 76/Ir/sub 24/ spin valves is investigated. Samples were fabricated by ion beam deposition (IBD), post-annealed in vacuum (10/sup...
Ferromagnetic coupling field reduction in CoFeB tunnel junctions deposited by ion beam
Cardoso, S., Ferreira, R., Freitas, P.P., MacKenzie, M., Chapman, J., Ventura, J.O., ...
In this paper, junctions with reduced H-f coupling were fabricated by ion beam deposition and oxidation, using CoFeB electrodes. The CoFeB layer has a strong (111) texture that can be the origin of...
Exchange enhancement and thermal anneal in Mn/sub 76/Ir/sub 24/ bottom-pinned spin valves
Haohua, Li, Freitas, P.P., Zhenjun, Wang, Sousa, J.B., Gogol, P., Chapman, J.
Exchange enhancement through thermal anneal in bottom-pinned Mn/sub 76/Ir/sub 24/ spin valves is investigated. Samples were fabricated by ion beam deposition (IBD), post-annealed in vacuum (10/sup...
Ferromagnetic coupling field reduction in CoFeB tunnel junctions deposited by ion beam
Cardoso, S., Ferreira, R., Freitas, P.P., MacKenzie, M., Chapman, J., Ventura, J.O., ...
In this paper, junctions with reduced H-f coupling were fabricated by ion beam deposition and oxidation, using CoFeB electrodes. The CoFeB layer has a strong (111) texture that can be the origin of...