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Fiber-reinforced polymers are increasingly being used, especially in lightweight structures. Here, the effective adaptation of mechanical or physical properties to the necessary application or manufacturing requirements plays an important role. In this context, the alignment of reinforcing fibers is often hindered by manufacturing aspects. To achieve graded or locally adjusted alignment of different fiber lengths, common manufacturing technologies such as injection molding or compression molding need to be supported by the external non-mechanical process. Magnetic or electrostatic fields seem to be particularly suitable for this purpose. The present work shows a first simulation study of the alignment of magnetic particles in polymer matrices as a function of different parameters. The parameters studied are the viscosity of the surrounding polymer as a function of the focused processing methods, the fiber length, the thickness and permeability of the magnetic fiber coatings, and the magnetic flux density. The novelty of the presented works is in the development of an advanced simulation model that allows the simulative representation and reveal of the fluid–structure interaction, the influences of these parameters on the inducible magnetic torque and fiber alignment of a single fiber. Accordingly, the greatest influence on fiber alignment is caused by the magnetic flux density and the coating material.

Die numerische Berechnung entstehender Kraftwirkungen auf Körper aufgrund magnetischer Wechselwirkungen zwischen diesen, ist in Bezug auf die mechanische Deformation dieser Körper ein noch nicht vollständig gelöstes Problem. In dieser Arbeit wird ein Vergleich vorhandener Kraftberechnungsmethoden hinsichtlich der totalen Kraft anhand eines analytisch berechenbaren Beispiels vorgestellt, sowie Unterschiede der lokalen Kraftdichten dieser Methoden in Anwendung auf die magnetische Beschichtung eines magnetischen Rasterkraftmikroskops aufgezeigt. Due to magnetic interactions between magnetic field inducing bodies, force effects occur on the materials. The numerical computation of those occuring forces with respect to a subsequent structural analysis of a deformable material is still a topic of interest in research. In this paper a comparison between several existent force calculation methods regarding the total force is given for an example with two magnetic cubes. Furthermore, differences are shown concerning the local force densities on the magnetic coating of a magnetic force microscope.

In this paper we investigate a hybrid quantum system comprising a mechanical oscillator coupled via magnetic induced electromotive force to an $LC$ resonator. We derive the Lagrangian and Hamiltonian for this system and find that the interaction can be described by a charge-momentum coupling with a strength that has a strong geometric dependence. We focus our study on a mechanical resonator with a thin-film magnetic coating which interacts with a nano-fabricated planar coil. We determine that the coupling rate between these two systems can enter the strong, ultra-strong, and even deep-strong coupling regimes with experimentally feasible parameters. This magnetomechanical configuration allows for a range of applications including electro-mechanical state transfer and weak-force sensing., 16 pages, 5 figures

We investigate the importance of using nanotips on a point contact spin-transfer torque (STT) experiment. A systematic analysis comparing the STT in a magnetic thin film in current-perpendicular-to-plane (CPP) geometry sample for magnetic coated and uncoated tungsten nanotips is shown. The STT effect presents a reverse resistance to current behavior when using a magnetic coating layer on the nanotips. We demonstrate that the magnetic layer on the tip may assume the role of a polarizer layer. This effect opens up the possibility of exploiting simpler architectures in STT-based devices, such as STT-random access memory (STT-RAM).

In order to improve the spatial resolution achieved by magnetic force microscopy (MFM) technique and its derivatives, we employ here advanced MFM tips fabricated by means of focused ion beam (FIB) milling. The magnetic coating applied on these tips is a CoCr film of 10 nm thickness. The MFM measurements on hard disk test samples reveal the achieved high resolution, and the measurement on a garnet film demonstrates the low invasiveness. High-frequency MFM (HF-MFM) is a development of the MFM technique to observe the HF stray fields emerging from magnetic recording writer poles at their operating conditions. By means of HF-MFM, magnetic recording writer poles are characterized in the frequency range 100–1,000 MHz. Up to now, all HF-MFM experiments conducted were using standard MFM cantilevers. From the HF-MFM images obtained using the advanced MFM cantilevers, it is clearly seen that the spatial resolution is considerably improved over the images obtained using standard MFM tips. However, the 10 nm thick magnetic coating of the cantilevers is found to work properly only at frequencies of up to about 500 MHz. SCANNING 30: 27–34, 2008. © 2008 Wiley Periodicals, Inc.

In this chapter Magnetic Force Microscopy is treated in detail. The emphasis is on high resolution and the design and realisation of MFM tips.

The separation of magnesite fines from serpentine fines by magnetic carrier methods has been examined in this study. The zeta-potential of serpentine, magnesite and magnetite was measured with and without dodecylamine as surfactant. The interaction energies between the particles were then calculated. Without the surfactant, no magnetic coating was obtained despite the favourable predictions for narrow pH ranges. When surfactant is added in suspensions of separate minerals, the serpentine particles obtain a magnetic coating strongly attached to the surface in the range 6 9. The experimental results are in excellent agreement with the theoretically predicted results for serpentine and in fairly good agreement for magnesite. When artificial mixtures of serpentine and magnesite were used, the metallurgical results are slightly different from the results on separate minerals.

To experimentally investigate the acoustical behavior of different dual-mode nanosized contrast agents (NPCAs) for echographic medical imaging at low ultrasound (US) frequency.We synthesized three different nanosized structures: (1) Pure silica nanospheres (SiNSs); (2) FePt-iron oxide (FePt-IO)-coated SiNSs; and (3) IO-coated SiNSs, employing three different diameter of SiNS-core (160, 330 and 660 nm). Tissue mimicking phantoms made of agarose gel solution containing 5 mg of different NPCAs in 2 mL-Eppendorf tubes, were insonified by a commercial echographic system at three different low US pulse values (2.5, 3.5 and 4.5 MHz). The raw radiofrequency signal, backscattered from each considered NPCA containing sample, has been processed in order to calculate the US average backscatter intensity and compare the acoustic behavior of the different NPCA types.The highest US contrast was exhibited by pure SiNSs; FePt-IO-coated SiNSs acoustical behavior followed a similar trend of pure SiNSs with a slight difference in terms of brightness values. The acoustic response of the examined NPCAs resulted function of both SiNS diameter and US frequency. Specifically, higher US frequencies determined higher value of the backscatter for a given SiNS diameter. Frequency-dependent enhancement was marked for pure SiNSs and became less remarkable for FePt-IO-coated SiNSs, whereas IO-coated SiNSs resulted almost unaffected by such frequency variations. Pure and FePt-IO-coated SiNSs evidenced an image backscatter increasing with the diameter up to 330 nm. Conversely, among the types of NPCA tested, IO-coated SiNSs showed the lowest acoustical response for each synthesized diameter and employed US frequency, although a diameter-dependent raising trend was evidenced.The US characterization of magnetically covered SiNS shows that FePt-IO, rather than IO, was the best magnetic coating for realizing NPCAs suitable for dual mode imaging of deep organs, combining US and magnetic resonance imaging.

While the properties of conductive fibres and coatings on textiles can easily be measured and calculated, magnetic coatings of fibres, yarns and fabrics still lack descriptions of their physical properties. Since magnetic textiles can be used for a variety of applications, from magnetic filters to invisible water-marks to magnetic coils and sensors, simulations would be supportive to understand and utilize their properties. The article gives an overview of different coatings on textile fibres, varying the magnetic materials as well as the fibre composition, giving rise to the interactions between neighbouring coated fibres. In this way, it is possible to understand the strong shape anisotropy which must be taken into account when the magnetic properties of textiles are to be tailored. Additionally, the differences between several possible magnetic coating materials become visible. This study can help adjusting the magnetic properties of textile fabrics to a desired application.

The uppermost pigment particles of a magnetic coating are covered by a thin layer of organic material. Compared to the bulk of the binder formulation, this layer is highly inhomogeneous. At the phase boundaries to air and pigments, concentration gradients are observed which influence the mechanical behavior of the coating, especially when changes take place that are effected by time and climatic conditions. By applying ESCA and SIMS techniques, important information on this surface layer could be obtained concerning: (1) the thickness of this layer, its distribution, and its differences between magnetic and nonmagnetic particles; (2) the incompatibilities and varying distribution of the components of a given formulation; and (3) the mobility of low molecular additives (alteration during changes of climatic conditions or transfer of substances onto contacting bodies). >

This paper discusses the important innovations in disk file manufacturing at IBM over the past twenty-five years. Technology advances in the key components of disk files- the magnetic read/write head, its air bearing support, and the disk substrate and magnetic coating- have permitted almost four orders of magnitude increase in areal recording density since the first disk file, the IBM 350, was shipped in 1957. Manufacturing capability for these basic recording technology components has been the key to realizing the cost/performance promise of each new technology. The evolution of this manufacturing capability is discussed with an emphasis on important innovations in processes, materials, tools, and testing techniques.

Experience with helical-scan videotape recorders has shown that the mechanical forces involved in handling the tape are sometimes sufficient to cause significant reductions in signal level due to stress demagnetization. A tape-loop recorder was used in an investigation of stress demagnetization in videotapes. Results are presented illustrating the magnitude of stress demagnetization and its dependence on the type of tape and the number of applications of stress. The bending stress resulting from the wrap of the tape around guides was studied in considerable detail. It is found that bending stress can greatly exceed other stresses involved in the normal handling of tape. Results are presented to show how bending-stress demagnetization depends on the depth of recording in the magnetic coating and on the radius of the guide. It is found that there is also a strong dependence on wrap angle around the guide. A new analysis is presented to explain the wrap-angle dependence and to permit calculation of bending-stress demagnetization.

Calendering of magnetic tape is applied to achieve a smooth magnetic coating. The purpose of this study is to gain a better understanding of the calendering process. The investigation is focussed on the roughness and elastoplastic deformation of the uncalendered coating, the substrate and the compliant roll material. It is found that these properties do determine the calendering efficiency to a great extent. Model calculations that are performed using the actual elasto-plastic deformation properties of coating and substrate, confirm the experimental results. A small-scale calender is developed with which coatings are calendered by means of a rolling ball. In this way small samples can be used and a large flexibility is obtained. Surface roughness and modulation noise are measured in order to characterize the calendering efficiency. The elasto plastic deformation properties are determined by means of ultra-microindentation measurements. Implementation of the results of this study resulted in an average surface roughness of 4 nm on lab-scale and of 6 nm on semi-production scale.

In this paper the advantages of connecting a tensile tester to a microcomputer are described. The advantage of this combination compared with the combination of tensile tester and conventional available data analyzer is a much better accuracy of the measurements of viscoelastic materials e.g. magnetic tapes. Using this hardware combination the spread on the measurements is reduced substantially. With this increased accuracy it is now possible to determine the Young's modulus of an actual magnetic coating by measuring the tape and subtracting the basefilm contribution. The justification for this procedure is given and followed by measurements of samples of different origins.

OF THE DISCLOSURE A process for producing a magnetic recording member comprising a non-magnetic support and a magnetic layer com-prising at least two layers on the non-magnetic support which comprises the steps of: (a) providing the lower magnetic layer on the non-magnetic support; (b) bringing the lower magnetic layer into contact with an organic solvent incapable of dissolving the lower magnetic layer; and (c) providing the upper magnetic layer on the lower magnetic layer by coating thereon a magnetic coating com-position, preferably containing the above organic solvent or a binder soluble in the above organic solvent.

A magnetic coating material for magnetic recording media is produced by dispersing a magnetic coating material containing from 0.1 to 2.0% of an abrasive and from 0.05 to 1.0% of a betaine type ampholytic antistatic agent, both on the basis of the amount of a magnetic powder, in a dispersion mill using steel balls. The abrasive has a hardness of not lower than 6 on Mohs' scale.

A magnetic recording medium which comprises a base and a magnetic layer of a magnetic coating composition comprising magnetic particles and a binder provided on said base, characterized in that the magnetic coating composition further comprises a dialkylsulfosuccinate.

A method for manufacturing a magnetic recording medium including the steps of applying a magnetic coating containing magnetic particles therein to a support, subjecting said support having the magnetic coating thereon to magnetic orientation treatment while the magnetic coating is still in fluid condition and thereafter drying the magnetic coating, characterized in that said magnetic orientation is effected by passing said support having the magnetic coating thereon through a magnetic orientation field generated from magnetic field generating means which comprises one or more permanent or DC magnets and an array of a plurality of parallel elongated members of a soft magnetic material arranged substantially in a plane close and parallel to said support and adapted to be magnetized by said magnet or magnets.