Observation of compact ferrimagnetic skyrmions in DyCo3 film.

Owing to the experimental discovery of magnetic skyrmions stabilized by the Dzyaloshinskii-Moriya and/or dipolar interactions in thin films, there is a recent upsurge of interest in magnetic skyrmions with antiferromagnetic spins in order to overcome the fundamental limitations inherent with skyrmions in ferromagnetic materials. Here, we report on the observation of compact ferrimagnetic skyrmions for the class of amorphous alloys consisting of 4f rare-earth and 3d transition-metal elements with perpendicular magnetic anisotropy, using a DyCo3 film, that are identified by combining X-ray magnetic scattering, scanning transmission X-ray microscopy, and Hall transport technique. These skyrmions, with antiparallel aligned Dy and Co magnetic moments and a characteristic core radius of about 40 nm, are formed during the nucleation and annihilation of the magnetic maze-like domain pattern exhibiting a topological Hall effect contribution. Our findings provide a promising route for fundamental research in the field of ferrimagnetic/antiferromagnetic spintronics towards practical applications.

Impact of Symmetry on Anisotropic Magnetoresistance in Textured Ferromagnetic Thin Films.

We report on the magnetoresistance of textured films consisting of 3d-ferromagnetic layers sandwiched by Pt. While the conventional cos^{2}φ behavior of the anisotropic magnetoresistance (AMR) is found when the magnetization M is varied in the film plane, cos^{2n}θ contributions (2n≤6) exist for rotating M in the plane perpendicular to the current. This finding is explained by the symmetry-adapted modeling of AMR of textured films demonstrating that the cos^{2}θ behavior cannot be used as a fingerprint for the presence of spin Hall magnetoresistance (SMR). Further, the interfacial MR contributions for Pt/Ni/Pt contradict the SMR behavior confirming the dominant role of AMR in all-metallic systems.

Endstation for ultrafast magnetic scattering experiments at the free-electron laser in Hamburg.

An endstation for pump-probe small-angle X-ray scattering (SAXS) experiments at the free-electron laser in Hamburg (FLASH) is presented. The endstation houses a solid-state absorber, optical incoupling for pump-probe experiments, time zero measurement, sample chamber, and detection unit. It can be used at all FLASH beamlines in the whole photon energy range offered by FLASH. The capabilities of the setup are demonstrated by showing the results of resonant magnetic SAXS measurements on cobalt-platinum multilayer samples grown on freestanding Si(3)N(4) membranes and pump-laser-induced grid structures in multilayer samples.

Breakdown of the x-ray resonant magnetic scattering signal during intense pulses of extreme ultraviolet free-electron-laser radiation.

We present results of single-shot resonant magnetic scattering experiments of Co/Pt multilayer systems using 100 fs long ultraintense pulses from an extreme ultraviolet (XUV) free-electron laser. An x-ray-induced breakdown of the resonant magnetic scattering channel during the pulse duration is observed at fluences of 5 J/cm(2). Simultaneously, the speckle contrast of the high-fluence scattering pattern is significantly reduced. We performed simulations of the nonequilibrium evolution of the Co/Pt multilayer system during the XUV pulse duration. We find that the electronic state of the sample is strongly perturbed during the first few femtoseconds of exposure leading to an ultrafast quenching of the resonant magnetic scattering mechanism.

Ultrafast optical demagnetization manipulates nanoscale spin structure in domain walls.

During ultrafast demagnetization of a magnetically ordered solid, angular momentum has to be transferred between the spins, electrons, and phonons in the system on femto- and picosecond timescales. Although the intrinsic spin-transfer mechanisms are intensely debated, additional extrinsic mechanisms arising due to nanoscale heterogeneity have only recently entered the discussion. Here we use femtosecond X-ray pulses from a free-electron laser to study thin film samples with magnetic domain patterns. We observe an infrared-pump-induced change of the spin structure within the domain walls on the sub-picosecond timescale. This domain-topography-dependent contribution connects the intrinsic demagnetization process in each domain with spin-transport processes across the domain walls, demonstrating the importance of spin-dependent electron transport between differently magnetized regions as an ultrafast demagnetization channel. This pathway exists independent from structural inhomogeneities such as chemical interfaces, and gives rise to an ultrafast spatially varying response to optical pump pulses.

Anisotropic interface magnetoresistance in Pt/Co/Pt sandwiches.

We report on an effect of reduced dimensionality on the magnetotransport in cobalt layers sandwiched by platinum. In a current in-plane geometry it is found that the resistivity depends on the magnetization orientation within the plane perpendicular to the current direction. The resistivity shows a symmetry adapted cos(2) dependence on the angle to the surface normal, with the maximum along the surface normal. The Co thickness dependence of the effect in Pt/Co/Pt sandwiches clearly points out that the mechanism behind this effect originates at the Co/Pt interfaces and is disparate to the texture induced geometrical size effect.

Imaging the in-plane magnetization in a Co microstructure by Fourier transform holography.

We report on experiments using Fourier transform holography to image the in-plane magnetization of a magnetic microstructure. Magnetic sensitivity is achieved via the x-ray magnetic circular dichroism effect by recording holograms in transmission at off-normal incidence. The reference beam is defined by a narrow hole milled at an inclined angle into the opaque mask. We present magnetic domain images of an in-plane magnetized cobalt element with a size of 2 µm × 2 µm× 20 nm. The domain pattern shows a multi-vortex state that deviates from the simple Landau ground state.

Nursing leaders predict top trends for 2000.

Nursing Management's Editorial Advisory Board predicts the top 10 trends that will impact nurse leaders in 2000. Use them to lead in the new millennium.

The joint commission. The future of the nurse executive: a standards focus.

A retrospective of joint Commission changes from it's early days to the present is provided in this column. How the Joint Commission on the Accreditation of Healthcare Organizations evolved from the American College of Surgeons initiative to standardize hospital systems and equipment is discussed. Structural standards developed into important functions that crossed departments within an organization. Discussion of the current initiatives and future challenges to improve care to the public is included.

Does the "C" in JCAHO stand for change?

A retrospective of joint Commission changes from its early days to the present is provided in this column. How the Joint Commission on the Accreditation of Health care Organizations evolved from the American College of Surgeons initiative to standardize hospital systems and equipment is discussed. Structural standards developed into important functions that crossed departments within an organization. Discussion of the current initiatives and future challenges to improve care to the public is included.

"Closet" incidents.

Learn what constitutes a sentinel event and how to identify possible system failures.

Question & Answer from the JCAHO. A'sourcebook' for leaders.

With nurse managers' role constantly changing, where can they turn for a leadership model? The Leadership function of the Comprehensive Accreditation Manual for Hospitals, 1998.

NR.1: What's the status?

After input from the field, JCAHO decided not to change NR.1 and, in fact, adopted (language that strengthens and clarifies the intent of the standard.

Counting, checking, and locking.

Medication Use (TX.3) stimulates many questions: Is the JCAHO driving your actions; is it a sacred cow; is it "we've always done it this way"; do the state, local, or federal laws and rules mandate that you do these things? The JCAHO requirements differ from other agency mandates-counting ensures an adequate supply of drugs and prevents diversion; checking maintains readiness; and locking controls and secures drugs.

Questions & answers from the JCAHO. What's new for 1999? Part 1.

Nurse managers can save time by reading this overview of the JCAHO's changes for 1999. Changes include a new performance improvement chapter and new nurse executive standards.

Questions & Answers from the JCAHO. What's new for 1999? Part II.

Part II of this series focuses on the JCAHO's changes in restraint use and implications for nurse managers.

Managing the environment of care.

The JCAHO chapter on Management of the Environment is ripe for nursing input. The issue of competence and orientation of staff, fire safety and smoking are all areas in which nurse managers could offer valuable insights.