Spin pumping is a mechanism that generates spin currents from ferromagnetic resonance over macroscopic interfacial areas, thereby enabling sensitive detection of the inverse Hall effect transforms into charge in nonmagnetic conductors. Here we study spin-pumping-induced voltages due to permalloy/normal metal bilayers integrated coplanar waveguides for different normal metals and as function angle applied magnetic field direction, well microwave frequency power. We find good agreement between...

The structural properties of ${\mathrm{La}}_{1\ensuremath{-}x}{\mathrm{Sr}}_{x}\mathrm{Mn}{\mathrm{O}}_{3+\ensuremath{\delta}}$ have been studied using neutron powder diffraction as a function both Sr doping ($0<~x<~0.225$) and oxygen partial pressure during synthesis [2.1\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}4}$ atm\ensuremath{\le}P(${\mathrm{O}}_{2}$)\ensuremath{\le}1 atm]. A phase diagram constructed these parameters has rhombohedral ($R\overline{3}c$), an...

Magnetic wedges of Fe on Cu(100) are explored magneto-optically. In the region 6--11 monolayers (ML) fcc grown at room temperature, in addition to a surface ferromagnetic layer with Curie temperature \ensuremath{\sim}250 K, bulk is antiferromagnetic N\'eel \ensuremath{\sim}200 K. This phase stable only above growth order below which spin-reorientation transition occurs \ensuremath{\sim}6 ML. The boundaries delineated by cusps coercivity along wedge.

The superconducting critical temperature (T(c)) of ferromagnet-superconductor-ferromagnet systems has been predicted to exhibit a dependence on the magnetization orientation ferromagnetic layers such that T(AP)(c)>T(P)(c) for parallel (P) and antiparallel (AP) configurations two layers. We have grown CuNi/Nb/CuNi films via magnetron sputtering confirmed theoretical prediction by measuring resistance system as function magnetic field. find an approximately 25% drop occurs near T(c) in...

We report a high-resolution experimental detection of the resonant behavior magnetic vortices confined in small disk-shaped ferromagnetic dots. The samples are magnetically soft Fe-Ni disks diameter 1.1 and $2.2\phantom{\rule{0.3em}{0ex}}\ensuremath{\mu}\mathrm{m}$ thickness 20 40 nm, patterned via electron-beam lithography onto microwave coplanar waveguides. vortex excitation spectra were probed by vector network analyzer operating reflection mode, which records derivative real imaginary...

We report direct imaging by means of x-ray photoemission electron microscopy the dynamics magnetic vortices confined in micron-sized circular permalloy dots that are 30 nm thick. The vortex core positions oscillate on a 10 ns time scale self-induced magnetostatic potential well after in-plane field is turned off. measured oscillation frequencies as function aspect ratio agreement with theoretical calculations presented for same geometry.

We experimentally demonstrate a biomagnetic sensor scheme based on Brownian relaxation of magnetic nanoparticles suspended in liquids. The characteristic time scale the can be determined directly by ac susceptibility measurements as function frequency. peak imaginary part shifts to lower frequencies upon binding target molecules nanoparticles. frequency shift is consistent with an increase hydrodynamic radius corresponding size molecule.

Superlattices of $({\mathrm{LaMnO}}_{3}{)}_{2n}/({\mathrm{SrMnO}}_{3}{)}_{n}$ ($1\ensuremath{\le}n\ensuremath{\le}5$), composed the gapped insulators ${\mathrm{LaMnO}}_{3}$ and ${\mathrm{SrMnO}}_{3}$, undergo a metal-insulator transition as function $n$, being metallic for $n\ensuremath{\le}2$ insulating $n\ensuremath{\ge}3$. Measurements transport, magnetization, polarized neutron reflectivity reveal that ferromagnetism is relatively uniform in state, strongly modulated high suppressed...

The spin diffusion length of Pt at room temperature and 8 K is experimentally determined via pumping Hall effect in permalloy/Pt bilayers. Voltages generated during excitation ferromagnetic resonance from the inverse anisotropic magnetoresistance were investigated with a broadband approach. Varying layer thickness gives rise to an evolution voltage line shape due superposition above two effects. By studying ratio components thickness, can be directly extracted. We obtain ∼1.2 nm ∼1.6 K.

We develop a method for universally resolving the important issue of separating spin pumping from rectification signals in bilayer spintronics devices. This is based on characteristic distinction and rectification, as revealed their different angular field symmetries. It applies generally analyzing charge voltages bilayers induced by ferromagnetic resonance (FMR), independent FMR line shape. Hence, it solves outstanding problem that device-specific microwave properties restrict universal...

Voltages generated from inverse spin Hall and anisotropic magneto-resistance effects via pumping in ferromagnetic (F)/non-magnetic (N) bilayers are investigated by means of a broadband resonance approach. Varying the non-magnetic layer thickness enables determination diffusion length Pd 5.5 +/- 0.5 nm. We also observe systematic change voltage lineshape when reversing stacking order F/N bilayer, which is qualitatively consistent with expectations effects. However, even after independent...

We report experimental and theoretical studies of the magnetization curves Fe/Cr(211) superlattices with antiferromagnetic interlayer coupling uniaxial in-plane anisotropy. There are substantial differences between structures an even odd number Fe layers, when magnetic field is applied along easy axis. For layered superlattices, inequivalence terminal layers gives rise to a surface spin-flop transition that evolves into bulk arrangement increasing field, as originally envisioned by Keffer...

A epitaxial orientation of Fe/Cr superlattices---Fe/Cr(211) on MgO(110)---is grown by magnetron sputtering. Its structural and magnetic characterizations are presented compared to those for Fe/Cr(100) superlattices simultaneously onto MgO(100) substrates. The the Fe/Cr(211) is Fe/Cr[01\ifmmode\bar\else\textasciimacron\fi{}1]\ensuremath{\parallel}MgO[001] Fe/Cr[1\ifmmode\bar\else\textasciimacron\fi{}11]\ensuremath{\parallel}MgO[11\ifmmode\bar\else\textasciimacron\fi{}0], while that...

A cylindrical-phase diblock copolymer ultrathin film is modified with vacuum UV light to selectively remove one of the surface domain components. The corrugated then serves as a template for self-organization colloidal magnetic nanoparticles (see Figure). This hierarchical methodology general route nanoscale assembly functional materials. work has ramifications potential future bit-patterned magnetic-storage media.

Co/Cu/Co sandwiches were grown by molecular beam epitaxy onto a Cu(100) crystal with the intervening Cu layer fabricated to be wedge shaped. Electron diffraction was used monitor layer-by-layer growth. Films 8, 14, and 20 monolayer- (ML) thick Co layers investigated in situ means of magneto-optic Kerr effect. Characteristic hysteresis loops along wedges, as function thickness, unambiguously identify oscillatory behavior sign exchange coupling between two films. The oscillation periodicity...

We use resonant soft-x-ray scattering (RSXS) to study the electronic reconstruction at interface between Mott insulator LaMnO3 and band SrMnO3. Superlattices of these two insulators were shown previously have both ferromagnetism metallic tendencies [Koida, Phys. Rev. B 66, 144418 (2002)10.1103/PhysRevB.66.144418]. By studying a judiciously chosen superlattice reflection, we show that density states exhibits pronounced peak Fermi level, similar predicted in related titanate superlattices by...

We demonstrate the injection of spin-polarized electrons into paramagnetic Au nanowires by driving an electric current from a ferromagnetic permalloy (Py) electrode. The nonequilibrium spin accumulation in results difference between chemical potentials for spin-up and spin-down that is detected as field-dependent voltage signal using second Py magnitude contrast (>10%) its coincidence with magnetic switching electrodes attest to spin-sensitive origin signals. By increasing separation...

The surface magneto-optic Kerr effect (SMOKE) is used to explore the magnetism of ultra thin Fe films extending into monolayer regime. Both bcc α-Fe and fcc γ-Fe single-crystalline, multilayer are prepared on bulk-terminated (1×1) structures Au(100) Cu(100), respectively. characterizations epitaxy growth mode performed using low-energy electron diffraction Auger spectroscopy. Monolayer range Fe/Au(100) ferromagnetic with a lower Curie temperature than bulk α-Fe. controversial γ-Fe/Cu(100)...

Nanomagnetism encompasses naturally occurring magnetic molecules and clusters as well artificially structured low-dimensional materials. Basic research areas include the pursuit of novel interfacial coupling spin-transport phenomena creating new electronic architectures. In addition to study fundamental phenomena, nanomagnets may in future form basis emerging technologies, such ultra-high density data storage media, ultra-strong permanent magnets, biological chemical sensing. Herein we...