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Studies the magnetic characteristics of 0.2x0.4x0.02 microm3 cobalt islands with the use of magnetic force microscopy (MFM) in the presence of an applied field. Synthesis and structure of the cobalt nanoparticles; Dispersion of easy axes; Macroscopic hysteresis loop.

Studies the magnetization distributions of an array of NiFe elements using Lorentz transmission electron microscopy and magnetic force microscopy. Experimental procedure; Aspect ratio and domain configuration; Domain wall imaging results.

Studies the magnetization reversal process in an array micron sized nickel-iron (NiFe) patterns using magnetic force microscopy in the presence of external fields. Characterizing the magnetic evolution of small magnetic elements; Results of the study.

Provides information on a technique for calibrating the force gradients and probe magnetic moment in phase-contrast magnetic force microscopy (MFM). Advantages of MFM in understanding surface magnetism; Method used to get an effective magnetic moment of the probe; Workability of this calibration method.

Abstract: Realization of pulsed-current selectable domain configurations of small permalloy islands is reported. In the islands with 65–100nm thickness and micron-sized lateral dimensions, the magnetic domain pattern can be uniquely set into either a four or seven closure domain configuration by applying either a positive or negative 10ns current pulse at the density of 107 A/cm2. The transition is completely reversible. This phenomenon appears to belong to a family of current-induced magnetization reordering, whose main mechanism appears to be domain wall motion due to s-d exchange force directed along the electron flow, and partially influenced by the Amperian field produced at the contact regions. This paper presents two cases, namely, bi-stable and tri-stable configurations, and discusses the mechanism as well as power requirements in using this approach for memory device applications. [Copyright &y& Elsevier]

We have investigated the role of aluminum oxide films as barriers to thermal oxidation of Co, Ni, Fe, Ni80Fe20, Mn, Ta, Cu and Cr in air. The oxidation of the film is monitored by measuring the electrical resistance following a brief anneal in air. We find that 0.3 and 1 nm Al protect the underlying metal film against thermal oxidation in air at temperatures of a few hundred degrees above the temperature at which the unprotected metal oxidizes. These results suggest that magnetic tunnel junction samples could be annealed in air after the oxidation of Al. The expected benefits of the annealing in air would include the oxidation of any remaining metallic Al, a more uniform Al2O3 thickness, and a sharper metal/Al2O3 interface. [Copyright &y& Elsevier]

Introduces a novel experiment technique of magnetic biasing for the magnetic force microscopy imaging. Linearity of the imaging system; Interpretation of images of magnetization patterns; Dipole response function.

Investigates the magnetic fields on recorded magnetic disk using a modified scanning tunneling microscope. Interaction between the local magnetic field and a thin film magnetic probe; Dependence of resolution and image contrast on the spatial orientation of the probe; Discussion on the method to control batch fabrication of probe tips.

Thin film oxides have attracted attention in implementations of gas sensors, notably NO 2 , owing to their unique physical, optical, and chemical properties. While the properties are presumed to be strongly dependent on the surface conditions of the thin films, it is not yet clear how surface properties of the thin film gas sensor affect its analyte sensing response. Here, we report the influence of surface carbon contamination and roughness on the NO 2 sensing properties of TiO 2 thin film sensors. The TiO 2 thin films were prepared by rf-sputtering. The surface of the films were intentionally contaminated and damaged with organic polymers (photolithography resist) and microwave plasma, respectively. The surface chemistry of the films was assessed by high resolution X-ray photoelectron spectroscopy, and atomic force microscopy was exploited to obtain the morphology of the fabricated sensors. The work aims to improve the long-term efficacy of gas sensors by studying the reasons for degradation in performance. Our results indicate that the carbon residue and surface roughness of the TiO 2 based sensor prolong the NO 2 response time by roughly threefold and fivefold, respectively. The recovery rate of the sensor is deteriorated by the poor surface conditions as well. [ABSTRACT FROM AUTHOR]

The dependence on nickel oxide thickness in unidirectional and isotropic exchange-coupled NiO/NiFe bilayer films was investigated by magnetic force microscopy to better understand exchange biasing at microscopic length scales. As the NiO thickness increased, the domain structure of unidirectional biased films formed smaller and more complex in-plane domains. By contrast, for the isotropically coupled films, large domains generally formed with increasing NiO thickness including a new cross type domain with out-of-plane magnetization orientation. The density of the cross domain is proportional to exchange biasing field, and the fact that the domain mainly originated from the strongest exchange coupled region was confirmed by imaging in an applied external field during a magnetization cycle. [Copyright &y& Elsevier]

The effect of annealing treatments (at T=250 °C) on both the structural and magnetic properties of sputtered (Co(dCo)/Au(22 A˚))×30 multilayers with dCo=6, 9 and 12 A˚ was studied. X-ray reflectivity and high angle diffraction measurements allowed us to estimate bilayer thickness and interface quality of the multilayers. Magnetic characterization, performed by alternating gradient force magnetometry, magnetic force microscopy and Brillouin light scattering from spin waves, indicates that all the as-prepared samples display perpendicular anisotropy. Upon annealing the perpendicular anisotropy for dCo=9 and 12 A˚ multilayers is enhanced while it is weakened for dCo=6 A˚. [Copyright &y& Elsevier]

Presents information on a study that observed the reversal of single domain permalloy particles with different particle interactions using magnetic force microscopy, and compared the theory of Jacobs-Bean chain of spheres model in the extreme case of maximally coupled magnetic elements. How the magnitude of the stray field can be estimated; Mechanism of magnetization reversal.