Compared to nerve stimulation or classic paraesthesia techniques, ultrasound (US)-guided popliteal sciatic block requires a smaller volume of local anaesthetic. The up-and-down method was used determine the minimum effective anaesthetic 0.5% ropivacaine necessary for US-guided achieve successful surgical anaesthesia foot and ankle surgery. study included 32 patients receiving an bock. starting dose set at 30 ml, which decreased by 3 ml if succeeded increased failed. After injection...

Tunneling magnetoresistance was found to be suppressed with decreasing temperature for magnetic tunnel junctions (MTJs) oxidized under high plasma power. A strong dependence of the junction resistance observed, along zero-bias anomalies dynamic at low temperatures. Resistance shows a logarithmic on temperature, and versus exhibits scaling behavior. Our experimental data can explained in consistent way by Kondo effect MTJs ${T}_{K}=20--30\text{ }\text{ }\mathrm{K}$.

The temperature dependence of tunneling magnetoresistance (TMR) is studied for spin valve type double-barrier tunnel junctions. Normalized TMR values junctions (DBTJs) and single-barrier (SBTJs) are plotted as functions it found that the DBTJ shows stronger than SBTJ. strong explained in terms polarization middle magnetic layer decrease coherence length with increasing temperature.

We study the effect of ferromagnetic (FM) contacts on spin accumulation in lateral spin-valve system for collinear magnetization configurations. When an additional FM electrode is introduced all-metallic system, we find that transresistance can be fractionally suppressed or very weakly influenced depending position electrode, and relative magnitudes contact resistance bulk defined over spin-diffusion length. Nonlocal signals such as nonlocal voltage drop leakage currents are independent...

Tunneling magnetoresistance (TMR) dependence on the Al2O3 barrier thickness was investigated for CoFe/Al2O3/CoFe magnetic tunnel junctions (MTJs). MTJs with very thin layers were grown by inserting an amorphous FeZr buffer layer whose role is only to reduce roughness of bottom electrode. The TMR decreased as reduced. results are analyzed spin-filtering effect thickness. It found that a simple model separating sp- and d-like electrons does not work, it may suggest tunneling in rather hybridized state.

Transmission of longitudinal optical (LO) phonons in double heterostructures with uniaxial anisotropy is investigated within a dielectric continuum model. When LO-like are generated the left semi-infinite layer, their transmission probability through barrier to right layer calculated. ${\mathrm{In}}_{x}{\mathrm{Ga}}_{1\ensuremath{-}x}\mathrm{N}/\mathrm{GaN}/{\mathrm{In}}_{x}{\mathrm{Ga}}_{1\ensuremath{-}x}\mathrm{N}$ and...

We calculate the interlayer exchange coupling in (111) $\mathrm{Co}/\mathrm{Cu}/\mathrm{Co}$ trilayers with tight-binding band structures two independent ways: a full-band calculation and an approximate terms of reflection amplitudes. An analytic Green's function method is used for calculation. The involves solving analytically each fixed in-plane wave vector $({\mathbf{k}}_{\ensuremath{\Vert}})$ accurate integration over ${\mathbf{k}}_{\ensuremath{\Vert}}$ nonuniform sampling. In method, we...

Abstract The transport properties of ferromagnet/Al 2 O 3 /semiconductor tunnel junctions were investigated. Si and GaAs substrates used, CoFe NiFe taken for ferromagnets. Diode characteristics observed in current‐voltage curves. dependences on the Al thickness temperature also studied. It is found that layer plays a crucial role preventing inter‐diffusion at interface. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Abstract Magnetic multilayers with the CoFe/FeZr ( t nm)/CoFe structure were investigated, where FeZr layer was a paramagnetic amorphous metallic alloy. Separate magnetization reversal observed for two CoFe layers when ≥ 2.0 nm, while they not magnetically separable < 2 nm. For all thicknesses, neither GMR effect, nor interlayer exchange coupling through observed, but negative AMR of 0.25% observed. The wave vector mismatch at interface is suggested main reason. (© 2004 WILEY‐VCH Verlag...

Abstract We investigated the physical origin of magnetic moment enhancements ordered Fe 50 Co alloys with B 2 and L 1 0 structures by using all‐electron total‐energy full‐potential linearized augmented plane wave (FLAPW) method within generalized gradient approximation. Pure Wigner‐Seitz radii taken from are also calculated for comparsion. It is confirmed that moments in enhanced significantly, while those remain almost unchanged. The enhancement alloy originates “ spin–flipping ” t g...

Magnetic tunnel junction (MTJ) structures were investigated by x-ray photoelectron spectroscopy. The Al layer was overoxidized and the samples treated rapid thermal annealing. It found that Mn atoms in exchange-bias diffused into magnetic layer, but did not reach oxide barrier. Although slightly higher oxygen concentration observed at interface between barrier, strong evidence of oxidized magnetic-layer found. Our result is consistent with high tunneling magnetoresistance MTJs room temperature.

We calculated the work functions (WFs) for high-index copper surfaces, (112), (321), and (413), as well low-index (111), (100), (110), using full-potential linearized augmented plane wave (FLAPW) method within both local density approximation (LDA) generalized gradient (GGA). It is found that GGA lowers rigidly WFs about 0.46–0.49 eV from values obtained by LDA, all experimental surfaces are in between LDA GGA. also WF does not decrease further, with higher indices than (112). This result...

Spin accumulation in magnetic tunnel junctions and lateral all-ferromagnetic spin valves is theoretically investigated by using a spin-dependent diffusive transport model. When electric current tunnels through barrier, occurs the ferromagnetic layer can be detected with nonlocal valve measurements. Depending on relative orientation of magnetization, signal has three different values determine bulk polarization material.

Abstract We have studied the spin polarization of HgCdTe by measuring Shubnikov‐de Haas oscillations. The magnetic field been applied in parallel and perpendicular to current. Relatively long relaxation time was observed since only conserved transition is allowed selection rules. electronic completely polarized when larger than 0.5 Tesla, which can be easily generated micromagnets deposited on surface specimen. Thus, spin‐manipulation such as up/down junction realized with this...

The spin Hall torque induced by DC current was studied experimentally. A Pt/Co/Pt structure with perpendicular magnetic anisotropy grown, and magnetization reversal due to the effect observed. An extra field sample applied in addition a constant bias field. It found that switching shifted proportion additional angle estimated from this relation, small can be measured accurately based on effect.

Nano-size magnetic tunnel junctions (MTJs) were fabricated by using e-beam lithography and oxidizing the top ferromagnetic (free) layer with inductively coupled plasma while junction area was covered PR. A significant improvement in physical properties of MTJ has been observed compared to those patterned conventional methods. The tunnelling magnetoresistance (TMR) 31% for 140 × nm2 at room temperature. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Two kinds of mechanisms for magnetic field sensors are discussed, namely, intrinsic and geometric magnetoresistance (IMR GeMR). extreme cases experimentally obtained in InAs HgCdTe, respectively, the results good agreement with numerical analysis by finite difference method (FDM). By adjusting aspect ratio rectangular samples, we show that (MR) can be enhanced several times. It is also found MR becomes almost independent factors strong IMR case. These applied to optimize semiconductor sensor...