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We suggest a type of "goggle" cell shape and discuss its switching mechanism in comparison with conventional shapes such as rectangular and elliptical shapes. For the goggle shapes, the dependence of the switching characteristics on the saturation magnetization, the free layer thickness, and the aspect ratio was studied. We found that the "L"-like astroid curve with an enlarged writing margin could be obtained from a goggle shape, especially when the aspect ratio is smaller than 2. This seems to be closely related with the kink formation. We also found that the writing margin could be improved further as the saturation magnetization and thickness of the free layer was optimized. [ABSTRACT FROM AUTHOR]

In this work, magnetic properties and thermal stability of antiferromagnetically coupled AFC medium with a CrMo spacer layer instead of the conventional Ru spacer layer were studied. It was found that a reduction of M[SUBr]/M[SUBs] could also be obtained in the AFC medium with a CrMo spacer layer due to the antiferromagnetic coupling, similar to the conventional AFC medium with a Ru spacer layer. Thermal stability ratio, K[SUBU]V/k[SUBB]T for the proposed medium was slightly smaller than that of the conventional AFC medium with a Ru spacer layer, but larger than that of a single magnetic layer medium. By a comparison of the switching field distribution and ΔM of the AFC medium with those of the conventional AFC medium, it is conjectured that the intergranular exchange coupling decreases when a CrMo is used as a spacer layer. [ABSTRACT FROM AUTHOR]

This paper presents results of finite element analysis of induction heating problems considering temperature dependence of material characteristics. In this analysis, we have used the three dimensional finite element method in order to correctly express the induction heating coil's shapes and to make clear its effects on temperature distributions. The heat conducting problem and the eddy current problem are coupled and solved by using step-by-step calculations. [ABSTRACT FROM AUTHOR]

The effect of the postannealing conditions of TiO2 thin films deposited using a radio frequency (rf) magnetron sputtering system on their electrical resistive switching characteristics was evaluated in the Pt/TiO2 /Pt structure, and the compositional change of the TiO2 thin films after resistive switching failure was investigated. The Pt/TiO2 /Pt structure with polycrystalline TiO2 showed a relatively more stable set/reset voltage dispersion and resistance difference between the high resistance state (HRS) and low resistance state (LRS) than those with amorphous TiO2. In the energy dispersive X-ray spectroscopy analysis of the TiO2 thin film in Pt/TiO2 /Pt with reset-stuck failure, in which the resistive switching from the HRS to the LRS failed after repeated resistive switching, the peak intensity of oxygen was significantly decreased compared with that before resistive switching and the decrease of the oxygen content was more noticeable near the top electrode than near the bottom electrode. Consequently, it is considered that the depletion of oxygen in the TiO2 thin film after multiple resistive switching cycles by successive voltage sweeping could be one of the main causes of the resistive switching failure phenomenon. [ABSTRACT FROM AUTHOR]

The main research focus of Web services is to achieve the interoperability between distributed and heterogeneous applications. Therefore, flexible composition of Web services to fulfill the given challenging requirements is one of the most important objectives in this research field. However, until now, service composition has been largely an error-prone and tedious process. Furthermore, as the number of available web services increases, finding the right Web services to satisfy the given goal becomes intractable. In this paper, toward these issues, we propose an AI planning-based framework that enables the automatic composition of Web services, and explore the following issues. First, we formulate the Web-service composition problem in terms of AI planning and network optimization problems to investigate its complexity in detail. Second, we analyze publicly available Web service sets using network analysis techniques. Third, we develop a novel Web-service benchmark tool called WSBen. Fourth, we develop a novel AI planning-based heuristic Web-service composition algorithm named WSPR. Finally, we conduct extensive experiments to verify WSPR against state-of-the-art AI planners. It is our hope that both WSPR and WSBen will provide useful insights for researchers to develop Web-service discovery and composition algorithms, and software. [ABSTRACT FROM PUBLISHER]

This work focuses on magnetic tunnel junctions with a MgO barrier layer made by RF-sputtering and radical oxidation. In case of RF-sputtered MgO, its crystal orientation, MR and RA values very sensitively depend on the chamber atmosphere. The MR ratio of 97% in radical oxidized MgO is obtained at 0.4 V, which is slightly higher than RF-sputtered MgO. Also, its RA is smaller than that of RF-sputtered MgO. These improved MgO properties are originated from the improvement of the crystal orientation of MgO(200) and the decrease of OH component within the MgO barrier. In addition, the breakdown voltage in radical oxidized MgO is higher than that of RF-sputtered MgO at the same MgO thickness. [ABSTRACT FROM AUTHOR]

Toggle switching mode MRAM is tested and characterized with respect to the free- and pinned-layer material and thickness. With magnetization curves, we were able to find the optimum thickness combinations of free-layer and spacer materials. For CoFeB where the intrinsic anisotropy field (Hi) is about 20-30 Oe, one needs to have a reasonably high exchange coupling field (Hex) to ensure large switching margin. In case of an NiFe/Ru/NiFe free-layer, Hi is usually much smaller than Hex, so that further decrease of Hex between two magnetic layers is needed. The pinned-layer roughness and thickness are other factors to be optimized to reduce the toggle switching field. High cell aspect ratio ≥3.0 helps to minimize the switching distribution and enhance the switching stability. [ABSTRACT FROM AUTHOR]

The dependence of the switching field distribution of magnetic random access memory cells on film roughness, saturation magnetization, film thickness, and cell aspect ratio is discussed. We found that a flat interface between the tunnel oxide and the magnetic film is very important in suppressing switching field variation For free-layer materials, NiFe, CoNiFe, CoFeB, and lamellar structures are examined. By trying various compositions of these materials, we have improved switching characteristics with small saturation magnetization and small thickness. Good results with laniellar structures suggest that the suppression of the grain growth in the ferromagnetic layer is another effective way to get enhanced switching characteristics. [ABSTRACT FROM AUTHOR]

Dependence of magnetic tunnel junction (MTJ) properties on seed layer, surface treatment and magnetic materials was investigated to improve TMR ratio. Roughness of tunnel oxide layer generated from seed layer roughness reduces TMR ratio as well as PA product owing to locally reduced oxide layer thickness. Crystallinity of seed layer is found to be important to enhance TMR ratio. Surface treatment with ion beam etching on a pinned layer Improves tunnel oxide uniformity providing higher TMR ratio. Also, highly polarized magnetic material increases TMR ratio but the effect of surface treatment is quite different depending on pinned layer material. [ABSTRACT FROM AUTHOR]

It was found that a reduction in M[SUBr]t can be obtained in the new antiferromagnetically coupled (AFC) medium with a CrMo spacer layer due to antiferromagnetic (AF) coupling, which is similar to the conventional AFC medium with a Ru spacer layer. From the results of ΔM and magnetic force microscopy (MFM), it was found that the intergranular exchange coupling decreases when CrMo is used as a spacer layer. Micromagnetic simulations of ΔM and MFM analyses gave consistent results with experiment, i.e., 1) AFC media with higher intergranular exchange coupling constant have larger magnetic cluster and higher ΔM peak and 2) the media with higher AF coupling constant have smaller magnetic cluster and smaller ΔM. In this paper, we propose that the media noise of the AFC media with a CrMo spacer layer may be improved by a reduction in the magnetic cluster size, due to the decrease of the intergranular exchange coupling between magnetic grains. [ABSTRACT FROM AUTHOR]