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Related papers: Current-Driven Magnetic Excitations in Permalloy-B…

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We have measured the statistical properties of magnetic reversal in nanomagnets driven by a spin-polarized current. Like reversal induced by a magnetic field, spin-transfer-driven reversal near room temperature exhibits the properties of…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 E. B. Myers , F. J. Albert , J. C. Saneky , E. Bonet , R. A. Buhrman , D. C. Ralph

We compare magnetoresistances (MR) and switching currents (I_s) at room temperature (295K) and 4.2K for Permalloy/N/Permalloy nanopillars undergoing current-induced magnetization switching (CIMS), with non-magnetic metals N = Cu, Ag, and…

Materials Science · Physics 2009-11-10 H. Kurt , R. Loloee , W. P. Pratt , J. Bass

From both theory and experiment, scattering of minority electrons is expected to be weaker than scattering of majority electrons in both dilute Fe(Cr) alloys and at Fe(Cr)/Cr interfaces. We show that Fe(Cr)/Cr/Fe(Cr) trilayer nanopillars…

Materials Science · Physics 2009-11-10 M. AlHajDarwish , A. Fert , W. P. Pratt , J. Bass

Current-induced magnetic excitations in Co/Cu/Co bilayer nanopillars ($\sim$50 nm in diameter) have been studied experimentally at low temperatures for large applied fields perpendicular to the layers. At sufficiently high current densities…

Mesoscale and Nanoscale Physics · Physics 2016-08-16 B. Özyilmaz , A. D. Kent , M. J. Rooks , J. Z. Sun

Two-level fluctuations of the magnetization state of pseudo spin-valve pillars Co(10 nm)/Cu(10 nm)/Co(30 nm) embedded in electrodeposited nanowires (~40 nm in diameter, 6000 nm in length) are triggered by spin-polarized currents of 10^7…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 A. Fabian , C. Terrier , S. Serrano Guisan , X. Hoffer , M. Dubey , L. Gravier , J. -Ph. Ansermet , J. -E. Wegrowe

Molecular beam epitaxy is used to fabricate magnetic single and double layer junctions which are deposited in prefabricated nanostencil masks. For all Co | Cu | Co double layer junctions we observe a stable intermediate resistance state…

Mesoscale and Nanoscale Physics · Physics 2021-03-25 N. Müsgens , E. Maynicke , M. Weidenbach , C. J. P. Smits , M. Bückins , J. Mayer , B. Beschoten , G. Güntherodt

The magnetic properties of trilayers consisting of a diluted magnetic alloy, CuMn (Cu0.99Mn0.01), a soft ferromagnet, Py(Ni0.8Fe0.2), and an antiferromagnet, alpha-Fe2O3, were investigated. The samples, grown by UHV magnetron sputtering,…

We demonstrate the magnetization reversal features in NiFe/IrMn/NiFe thin-film structures with 40% and 75% relative content of Ni in Permalloy in the temperature range from 80 K to 300 K. At the descending branches of the hysteresis loops,…

Mesoscale and Nanoscale Physics · Physics 2019-04-01 Ch. Gritsenko , I. Dzhun , M. Volochaev , M. Gorshenkov , G. Babaytsev , N. Chechenin , A. Sokolov , Oleg A. Tretiakov , V. Rodionova

Current-induced magnetic excitations in Cu/Co/Cu single layer nanopillars (~50 nm in diameter) have been studied experimentally as a function of Co layer thickness at low temperatures for large applied fields perpendicular to the layers.…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 B. Oezyilmaz , A. D. Kent , J. Z. Sun , M. J. Rooks , R. H. Koch

Using measurements of the spectra of microwave-frequency resistance oscillations, we determine the phase diagram of magnetic excitations caused by torques from DC spin-polarized currents in (thin permalloy)/copper/(thick permalloy)…

We show that dipole-field induced antiferromagnetic coupling, or RKKY ferromagnetic coupling, between Co layers can strongly affect the low magnetic field switching behavior of Co/Cu/Co nanopillars. Whereas current-assisted switching at low…

Materials Science · Physics 2007-05-23 S. Urazhdin , W. P. Pratt , J. Bass

We present a study of the pulsed current switching characteristics of spin-valve nanopillars with in-plane magnetized dilute permalloy and undiluted permalloy free layers in the ballistic regime at low temperature. The dilute permalloy free…

Magnetic phase diagrams of the metamagnetic shape memory alloys Ni50-xCoxMn31.5Ga18.5 (x = 9 and 9.7) were produced from high-field magnetization measurements up to 56 T. For both compounds, magnetic field induced martensitic…

We have measured the superconducting transition temperature T_c of F/S/F trilayers using Permalloy (Py=Ni_84 Fe_16) as a strongly polarized ferromagnetic material. For a parallel (P) or anti-parallel (AP) alignment of the magnetization…

Superconductivity · Physics 2012-08-27 Ion C. Moraru , W. P. Pratt, , Norman O. Birge

Measurements of magnetic hysteresis loops in single Co nanoparticles at dilution refrigerator temperatures are presented. The nanoparticles are in electric contact with bulk Al leads via tunnel junctions. The tunnel current versus magnetic…

Mesoscale and Nanoscale Physics · Physics 2012-07-10 F. Tijiwa Birk , W. Jiang , D. Davidović

We test whether current-induced magnetization switching due to spin-transfer-torque in ferromagnetic/non-magnetic/ferromagnetic (F/N/F) trilayers changes significantly when scattering within the N-metal layers is changed from ballistic to…

Materials Science · Physics 2009-11-13 N. Theodoropoulou , A. Sharma , W. P. Pratt , J. Bass , M. D. Stiles , J. Xiao

Slow magnetic relaxation and two level fluctuations measurements under high current injection is performed in single-contacted ferromagnetic nanostructures. The magnetic configurations of the samples are described by two metastable states…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 J. -E. Wegrowe

The results of large-scale simulations investigating the dynamics of magnetization reversal in arrays of single-domain nanomagnets after a rapid reversal of the applied field at nonzero temperature are presented. The numerical micromagnetic…

Materials Science · Physics 2009-10-31 Gregory Brown , M. A. Novotny , Per Arne Rikvold

Magnetic properties of a polycrystalline alloy Ni$_{2.19}$Mn$_{0.81}$Ga, which undergoes a first-order magnetostructural phase transition from cubic paramagnetic to tetragonal ferromagnetic phase, are studied. Hysteretic behavior of…

We report on the electric field control of magnetic phase transition temperatures in multiferroic Ni3V2O8 thin films. Using magnetization measurements, we find that the phase transition temperature to the canted antiferromagnetic state is…

Materials Science · Physics 2007-11-28 P. Kharel , C. Sudakar , A. B. Harris , R. Naik , G. Lawes