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Problem statement: The electroplating technique is especially interesting due to its low cost, high throughput and high quality of deposit. Magnetic thin films are extensively used in various electronic devices including high density recording media and Micro Electro Mechanical (MEMS) devices. So we examined FePt films and give good magnetic properties. Approach: The Pt-rich FePt alloys were electrodeposited galvanostatically by various temperature baths. Results: The elemental percentage of Pt in the film was very high determined by X-ray spectroscopy. Surface characterization was carried out by using X-Ray Diffractometer (XRD) and Scanning Electron Microscope (SEM).The magnetic properties determined by Vibrating sample magnetometer. Hardness and adhesion of the films were also discussed. Conclusion/Recommendation: The films were soft magnetic character of lower temperature bath and become a hard magnetic character of higher temperature bath. Therefore this magnetic films could be an important material for incorporate in Micro electro mechanical devices. Key words: FePt, electrodeposition, magnetic film, magnetic properties, INTRODUCTION With the progress in the field of Micro Electro Mechanical System (MEMS) technologies (1), (2), (3), (4), (5) there has been growing interest in developing electroplated, nanostructured soft and [...]

The FePt:C films with different volume fractions of carbon were epitaxially grown on the CrRu(200) underlayer with Pt and MgO intermediate layers. The magnetic properties and microstructure of these FePt:C films were investigated. The FePt:C films grown on Pt intermediate layer consisted of a continuous layer of FePt, with overlying granular FePt grains. The FePt:C films grown on MgO intermediate layer consisted of a granular FePt:C layer with overlying granular grains. The formation of the overlying granular FePt grains was attributed to carbon diffusion to the surface, which resulted in the second nucleation of FePt. The different interface energy and surface energy of FePt on Pt and MgO intermediate layers caused the formation of initial continuous FePt layer on Pt intermediate layer and initial granular FePt layers on MgO intermediate layer. The out-of-plane coercivity measured at room temperature increased from 10.2 to 19 kOe when C concentrations increased from 0 to 15%. Further increasing the C contents to 20% and 25% caused the decrease of coercivity to 17.2 and 14.8 kOe, respectively. The coercivity of the exchange coupling assisted FePt:C perpendicular media was indeed substantially reduced. Index Terms--FePt, high coercivity, microstructure, perpendicular media.

Perfluoropolyether lubricant films on magnetic disks were observed by means of atomic force microscopy (AFM) with a fluoride-coated probe. The lubricant films could be observed directly because the adhesion force was decreased by the anti-wetting effect of the fluoride coating on the probes. We compared the molecular conformation of Z-dol (Mw: 2000, 3000, 6000, 8000) with that of Z-tetraol. Thus, we found that the film coverage of a lubricant with high molecular weight exhibited varying (i.e., higher and lower) step heights of the lubricant film boundary. The Z-tetraol film exhibited higher coverage and the higher step height as compared to Z-dol2000. To further study the step height measured by means of atomic force microscopy, we compared the step height with the shoulder height of the spreading profiles of the films. The step heights were almost equal to the shoulder height. We observed the lubricant film after shearing by using contact scanning mode atomic force microscopy. The coverage of the sheared lubricant film increased higher than the initial coverage before shearing. Subsequently, the lubricant molecular conformation was varied due to the shearing, and the coverage was increased. Index Terms--Atomic force microscope, lubricant, magnetic disk, perfluoropolyether.

Thermally assisted magnetic recording (TAMR) is one of the novel technologies that are employed for achieving magnetic recording densities higher than 1 Tb/[in.sup.2]. With regard to this novel technology, it has been suggested that there exists a critical head-disk interface (HDI) issue associated with the use of ultrathin liquid lubricant films on the disk surface. This problem is attributed to the fact that these films are heated to high temperatures by using laser beams in order to reduce magnetic coercivity. In this study, a fundamental research on the lubricant depletion caused due to laser heating in TAMR systems was conducted. That is, the effect of lubricant film materials on lubricant depletion was investigated. In this experimental study, four types of lubricant film materials--Zdol2000, Zdol4000, Ztetraol2000, and A20H2000--were used, and the differences in the characteristics of lubricant depletion for each tested lubricant film were investigated. The effect of the molecular weight as well as the end group of the lubricant on the lubricant depletion was discussed and clarified by analyzing the obtained experimental results. In addition, it was found that the depletion characteristics of ultrathin liquid lubricant films could be explained by using experimental results obtained from the thermogravimetric analysis for each bulk lubricant material. Index Terms--Hard disk drives, laser heating, lubricant depletion, perfluoropolyether lubricant film, thermally assisted magnetic recording systems, thermogravimetric analysis (TGA).

A linear magneto-impedance (MI) sensor integrated into a FePt thin film bias magnet which has in-plane isotropic magnetic property was investigated. The maximal bias field of 13.1 Oe was obtained after magnetizing a 1.3-[micro]m thick FePt film in longitudinal direction of the sensor element. The bias field changed with the magnetizing angle. By controlling the angle in the magnetizing direction of the bias magnet and sensing direction, it was shown to be able to adjust the effective bias field after fabrication of the sensor element. Index Terms--Bias field, magnetizing angle, magneto-impedance (MI), thin film magnet.

To guarantee a successful fabrication of magnetic micro devices, attaining the desired properties of magnetic thin- films is a precondition. This is particularly true for anisotropic magnetic films. This paper presents the development and fabrication of a micro hysteresis sensor chip consisting of two independent sensors oriented perpendicular to each other. Such an approach allows measuring the properties of anisotropic magnetic thin-films along the two desired axes. The paper describes design, fabrication, and evaluation of the micro hysteresis sensor. Index Terms--BH-loop, magnetic MEMS, micro hysteresis sensor, thin-film technology.

Magnetic thin films have been obtained by radio-frequency (RF) sputtering on [Si.sub.3][N.sub.4] substrates from a [Fe.sub.78][B.sub.13][Si.sub.9] target. The samples, with thickness t varying from 25 to 300 nm, are amorphous; crystalline fraction develops only for t [greater than or equal to] 300 nm. Static hysteresis loops have been measured at room temperature by means of an alternating gradient magnetometer. Samples-having t > 80 nm display a two-slope hysteresis loops: first steep magnetization jump followed by a linear behavior between remanence and saturation revealing the occurrence of a spin-reorientation transition (SRT). The magnetic field [H.sub.K] at which the saturation is reached is connected with the perpendicular anisotropy. Magnetic force microscopy has been performed on all samples, indicating that for t [less than or equal to] 80 nm the magnetization lies in the film plane, while for larger thickness, it is oriented perpendicularly to the film plane. In this work, SRT has been studied as a function of sample thickness and perpendicular anisotropy. In particular, the effect of furnace annealing on the transition from in-plane to out-of-plane configuration will be studied in details. Index Terms--Magnetic films, magnetic force microscopy, magnetization processes.

The magnetization reversal process of Fe thin film wire is analyzed based on two-dimensional micromagnetic simulation. The anisotropic dependence of wall energy in the direction of the external field is used for describing the behaviors of the thin films.

In order to achieve a magnetic recording density of 1 Tb/[in.sup.2], the spacing is expected to be less than 2-3 nm. However, a critical issue in achieving such an ultralow spacing is the dynamic instability of the head disk interface (HDI). That is, the experimentally observed hysteresis of fly sliders. The phenomenon of slider hysteresis has two features: slider touchdown and slider takeoff The goal of this research is to experimentally clarify the effects of the lubricant bonded ratio as well as the lubricant film thickness on slider hysteresis behavior in detail. It also aims to determine the contributing factors. In this study, the difference in the touchdown and takeoff velocities was monitored by varying the lubricant bonded ratio and lubricant film thickness of the disks. Furthermore, the correlation between the observed phenomenon and the variation in the experimental parameters was investigated. The results showed that the touchdown velocities were almost independent of the lubricant bonded ratio, while the takeoff velocities were greater for a lubricant with a higher bonded ratio. These results were obtained for a constant lubricant film thickness of around one monolayer. Therefore, the slider hysteresis was greater for a lubricant with a higher bonded ratio. With regard to the effect of lubricant film thickness, it was observed that the touchdown and takeoff velocities were greater for thinner lubricants. These results for the effect of lubricant film thickness are very similar to those obtained by Ambekar, Gupta, and Bogy (2005, ASME J. Tribol., 127(3), pp. 530-536). However, the slider hysteresis was greater for thicker lubricants. Considering these experimental results as well as the experimental data for the effect of the surface roughness of a disk on the slider hysteresis obtained by (Tani et al. (2006, J. Appl. Phys., 99(8), pp. 08N104-1-08N104-3), it was suggested that the variation in the touchdown velocity is due to a variation in the intermolecular forces. Furthermore, it was suggested that the variation in the takeoff velocity is caused by a variation in the friction forces between the slider and disk surface. This occurs because the takeoff velocity was greater for a lubricant with a higher bonded ratio or a thinner lubricant, which only has a small fraction of free mobile lubricant. The results predicted by the simulations are consistent with those observed experimentally. In addition, a design guideline for next-generation HDI, with small touchdown and takeoff velocities, resulting in small slider hysteresis, is discussed in detail in this paper. [DOI: 10.1115/1.2736448] Keywords: hard disk drives, head-disk interface, slider hysteresis, molecularly thin liquid lubricant films

The micromagnetic simulations and analytical studies of the nonhomogeneous magnetization states of ultrathin films with perpendicular and in-plane anisotropy is reported. The topological frustrations observation from mapped phase diagram of magnetization states (ground and metastable) of ultrathin films could be applied to enhance the design of high density magnetic recording media.

Ferromagnetic resonance (FMR) is used for examining the effect of thickness and substrate on the magnetic properties of Co/Si(100) and Co/glass thin films. The linewidth analysis has shown that the surface region is magnetically more homogeneous than the interfacial region and the spin wave resonance modes are associated to dynamic pinning.

The effect of electron bombardment on the structural, morphological, coloration and luminescent properties of pulsed dc magnetron sputtered W[O.sub.3] thin films is examined. The changes in the physical properties are attributed to the extraction of oxygen atoms from the sample and the structural modifications induced by electron bombardment.

Study presents a complete study of the dispersion formula and dynamic magnetization for magnetostatic waves (MSSWs), in addition to the observation of the mode-conversion enhancement of guided optical waves (GOWs). The results show that the mode-conversion efficiency of the GOWs can be highly improved by optimizing the direction of the bias magnetic field in the plane of the film.

The multilevel fast multipole algorithm (MLFMA) is an established way to accelerate the solution of the integral equations governing scattering of electromagnetic waves. Another way is to use high-order methods, of which the locally corrected Nystrom (LCN) method is, perhaps, the best; it has been applied to metallic scatterers up to order 10. In this paper, the technique (MLFMA + LCN) is extended to handle mixed conducting/dielectric bodies. Results for coated circular and square cylinders, using orders up to 8, demonstrate the efficiency of the method. Index Terms--Boundary element methods, dielectric films, electromagnetic scattering, multilevel systems.

Multilayers of 200-nm thick Co-free or Co-doped Nd-Fe-B with 10-nm thick Ta were prepared by sputtering on heated glass substrates and investigated into the microstructure, texture and hard magnet properties. The perpendicularly textured [Nd.sub.2][Fe.sub.14]B grains evolved in the multilayers with sizes neatly controlled by the thickness of the unit layer. Co was found to dissolve in the [Nd.sub.2][Fe.sub.14]B grains, resulting in the enhanced c-axis texture possibly due to the modulated surface energy of the [Nd.sub.2][Fe.sub.14]B phase. It was also found that Co boosts the crystallization and grain growth of the [Nd.sub.2][Fe.sub.14]B phase, rapidly leading to the relatively stable multilayered structure where the dimension of the [Nd.sub.2][Fe.sub.14]B grains is exactly defined by the thickness of the unit layer. Such effect of Co suppresses the local variation of the microstructure and minimizes the deterioration of the permanent magnet properties of the multilayer with an increased thickness of 10-[micro]m. Index Terms--Permanent magnets, perpendicular magnetic anisotropy, sputtering, thin films.

A study is conducted on the influence of surface roughness on the magnetization dynamics of soft magnetic nanocrystalline Fe-Zr-N thin films deposited onto a Si oxide, a thin polymer layer, and a thin Cu layer. Details of the demagnetizing factors caused by the sample roughness that were calculated on the basis of the atomic force microscopy (AFM) analysis of the surface topography are discussed.

The strain effects on the structural and magnetotransport properties of Pr0.67Sr0.33MnO3 (PSMO) thin films are studied. The results show that the peak temperature (Tp) of the PSMO films is suppressed and the MR effects enhanced by strain-induced lattice distortions and the thickness dependence of Tp and high-field magnetoresistance (HFMR) show evidence for the Jahn-Teller (J-T) effect in strained films.

The magnetic properties and microstructure of CrRu/FePt bilayer and CrRufFePt/CrRu trilayer deposited by dc magnetron sputtering on preheated natural-oxidized Si (100) wafer substrates were studied. It is found that both the in-plane coercivity ([Hc.sub.//]) and grain size of the FePt film increase with increasing the thickness of CrRu underlayer. The [Hc.sub.//] value of the FePt film is further increased but the grain size is decreased as adding a CrRu capped layer on the FePt film. The granular L[1.sub.0] FePt nanoparticles with in-plane coercivity of 2300 Oe and isolated uniform size of 6.61 nm are achieved from the CrRu(15 nm)/FePt(25 nm)/CrRu(4 nm) film deposited at a low substrate temperature of 350[degrees]C. Index Terms--CrRu/FePt bilayer, CrRu/FePt/CrRu trilayer, in-plane coercivity, magnetron sputtering.

We report the synthesis of zinc-blende CrTe (zb-CrTe) as highly oriented crystalline grains in films of 100-nm thickness. The structural properties of the film were characterized using high-resolution transmission electron microscopy (HRTEM) and selective-area electron diffraction (SAED). Temperature-dependent magnetization measurements show that the Curie temperature of the film is ~327 K. Angular M-H measurements indicate that the CrTe films have an in-plane easy axis of magnetization along the [0[bar.1]1] direction of GaAs. Index Terms--CrTe, ferromagnetic, molecular-beam epitaxy, zinc-blende.

Ru thickness ([d.sub.Ru]) dependence of flopping field ([H.sub.f]) was investigated in subnano-crystalline [([Co.sub.100-x[Fe.sub.x]).sub.88][B.sub.12]/Ru/ [([Co.sub.100-x[Fe.sub.x]).sub.88][B.sub.12] films with various Fe content, x. The [H.sub.f] with [d.sub.Ru] showed oscillatory behavior with the period of 1.5 nm of [d.sub.Ru], which was independent of the Fe content. The first peak of [H.sub.f] takes the maximum value at x = 65 at.%, and the second peak was degenerated with increasing the Fe content. These results are analyzed in terms of interlayer coupling effect including the bilinear ([J.sub.1]) and biquadratic ([J.sub.2]) coupling energy. As the [d.sub.Ru] decreases, the [J.sub.1] oscillates and [J.sub.2] monotonously increases. Although the [J.sub.2] effect appeared at thinner [d.sub.Ru], i.e., [d.sub.Ru] < 0.7 nm, the [J.sub.1] effect was rather stronger than the [J.sub.2] one. The magnitude of the first peak of [J.sub.1] was greatly enhanced with increasing Fe content, and took the maximum at x = 65 at. %. Therefore, a smooth interface was established in subnano-crystalline FeCoB, and the intrinsic strong [J.sub.1] was realized in FeCoB/Ru/FeCoB system even in ultrathin [d.sub.Ru] of 0.3 nm. Index Terms--Interlayer coupling, perpendicular recording medium, soft magnetic underlayer, subnano-crystalline FeCoB.

We prepared Ti/CoCrPt/Ti pseudo-sandwich granular films by radio-frequency and dc magnetron sputtering onto glass substrates and subsequent in situ annealing. We investigated the microstructure and magnetic properties of the films as a function of Ti overlayer thickness (x). X-ray diffraction profiles show that the CoCrPt magnetic layers are formed as the hexagonal close-packed (HCP) structure. Vibrating sample magnetometer measurements indicate that the out-of-plane coercivity reaches the maximum 1675.5 Oe when x = 5 nm. Atomic force microscopy images show the minimum average grain size D = 7.2 nm and the average roughness [R.sub.a] = 1.0 nm. Magnetic force microscopy images show that the minimum average magnetic cluster size is about 6.4 nm at x = 5 nm. Index Terms--Coercivity, magnetic granular films, overlayer, perpendicular recording media.

Magnetic domain nucleation site distributions within a perpendicular magnetic film were measured by magnetically confining nucleated domains within small regions in the film. The confinement was achieved by placing a high coercivity layer adjacent to the layer under test and using the stray fields from domains recorded in this layer to magnetostatically halt domain wall motion in the test layer. Experimental results confirm the functionality of this method, and are shown for two samples with different magnetic properties. Index Terms--Coercivity, magnetic domains, magnetization processes, magnetooptic films, measurement, nucleation.

A magnetic material based on cobalt-nickel-rhenium-tungsten-phosphorus (Co-Ni-Re-W-P) composition has been developed by electrochemical deposition. With proper control of process conditions, hard magnetic films with high out-of-plane remanent magnetization (Mr) of 3.11 kG and coercivity (Hc) of 2.33 kOe are achieved. Fabrication of Co-Ni-Re-W-P in the form of microcylindrical arrays of ~50 [micro]m diameter and 90 [micro]m height enhances the vertical anisotropy to a vertical Mr of 5.15 kG and Hc of 2.02 kOe. The materials and fabrication technique of microstructures as reported could be applied for the fabrication of magnetic microelectromechanical systems. Index Terms--Cobalt alloys, cylindrical arrays, electrochemical processes, magnetic films, perpendicular magnetic anisotropy.

We have realized perpendicular hard/soft bilayers with exchange-spring behavior, based on FePt-[L1.sub.0] and Fe. Studying the magnetization process as a function of the soft-layer thickness, two different coupling regimes have been identified, i.e., the rigid-magnet and exchange-spring regimes. High values of the maximum energy product (12.4 MGOe) and remanent magnetization (750 emu/[cm.sup.3]) have been found in the exchange-coupled bilayers. Index Terms--Iron alloys, permanent magnets, perpendicular magnetic anisotropy, thin films.

To explore the possibility of FePt-based soft/hard nanocomposite magnets, granular films were prepared by annealing Pt/Fe, FePt/Fe, and FePt/[Fe.sub.3] Pt multilayers. Although a high coercivity of 12 kOe was obtained by annealing the [Fe.sub.3]Pt/FePt multilayers, only a small remanence was obtained due to random orientation of L[1.sub.0]FePt grains. By introducing oxygen during the film deposition, a few nanometer oxide particles were observed within the FePt grains and [H.sub.c] increased at the expense of [M.sub.r]. A possible way to achieve a higher value of [(BH).sub.max] is discussed based on the relationship between the microstructure and magnetic properties. Index Terms--Coercivity, energy product, exchange coupling, multilayer, nanocomposite magnets.

Magnetic properties of [Fe.sub.49-x][Co.sub.x][Pt.sub.51] (x = 0.0, 0.7, 1.3. and 2.2) thin films are investigated. Cobalt is found to enhance the magnetization and energy product of the films. A maximum energy product of 18.4 MGOe is obtained at x = 1.3. This value is 87% larger than that of a binary FePt film. High-saturation magnetization of [M.sub.s] = 1180 emu/[cm.sup.3] and remanent magnetization of [M.sub.r] = 862 emu/cm3 are obtained as the sample with x = 1.3 was annealed at 500 [degrees]C. The addition of cobalt increases the ordering temperature of the film, which retains more disordered phase in the film and thus produces higher magnetization than the binary sample. Exchange coupling is found to exist between ordered and disordered FePt phases. The intensive intergranular exchange coupling also makes the switching of magnetic moments in the thin film more cooperative. We consider that both the magnetization enhancement and the cooperated switching behavior in the thin film are responsible for the increased energy product. Index Terms--Coercive squareness ratio, energy product, exchange coupling, Fe-Pt-Co, permanent magnets, thin films.

Single-layer polyerystalline [Fe.sub.52][Pt.sub.48] alloy thin films were deposited on preheated natural-oxidized (100) silicon wafer b y conventional sputtering method at room temperature. The as-deposited films are soft fee FePt phase. After suitable temperature annealing and furnace cooling, the as-deposited films are transformed from disordered soft fcc FePt phase into ordered fct L[1.sub.0] FePt phase. The ordering temperature of L[1.sub.0] FePt phase could be reduced to about 350[degrees]C by preheating substrate to 300[degrees]C followed by furnace cooling treatment. The grain size of FePt was found to decrease as the ordering temperature of L[1.sub.0] FePt phase was reduced. After annealing at 350[degrees]C for 1 h, the in-plane coercivity ([H.sub.c']) of the 100-nm [Fe.sub.52][Pt.sub.48] alloy thin film is about 6 k0e, and the average grain size is about 6 nm. Index Terms--Grain size, order-disorder transformations, sputtering.

When demagnetized [La.sub.1-x] [Sr.sub.x]Mn[O.sub.3] (LSMO) thin films are magnetized by a local magnetic field from a scanning magnetic tip without an external magnetic field, a magnetic ripple pattern appears on the LSMO surface. The magnetic ripple pattern, consisting of magnetic ripples with varying magnetic periods, is different from the conventional pattern magnetized by an external field. The magnetic ripples with longer magnetic periods have a larger magnitude of magnetic moment. However, the magnitude of the remanent magnetization induced by the magnetic force microscopy (MFM) tip is close to that induced by the external field. Since the MFM images of the magnetic ripples with varying periods can be converted to inverse images and spectra by a fast Fourier transformation (FFT), the inverse FFT images and spectra are also used to probe the magnitude of magnetic moment of the periodic magnetic ripples. Index Terms--Fast Fourier transformation (FFT), [La.sub.1-x][Sr.sub.x]Mn[O.sub.3] (LSMO), magnetic force microscopy (MFM), magnetic ripple.

The interfacial mixing phenomenon for Fe-Al magnetic thin-film system was quantitatively investigated using molecular dynamics simulation. The Fe-Al system has shown different characteristics such as layer coverage function and mixing length, compared with other ferromagnetic/nonferromagnetic metallic bilayer systems. The different intermixing behavior could be successfully explained in terms of cohesive energy and local acceleration effect. In addition, it can be clearly seen that intermixing was rather insensitive to changes in the adatom kinetic energy but dependent on the substrate temperature. Index Terms--Fe-Al bilayer system, interfacial intermixing, molecular dynamics simulation, thin films.

Magnetoimpedanee (MI) in RF sputtered magnetic/metallic multilayers of composition NiFe/Au/NiFe has been investigated with the purpose of clarifying the effect of in-plane size. The film width was varied between 20 [micro]m and 200 [micro]m, the length was 2 or 5 mm and the layer thickness was 0.5 [micro]m. The films of 50 [micro]m wide demonstrated the highest MI ratio of more than 140% for frequencies of 200-400 MHz. We believe this is one of the best obtained results regarding the film dimensions and sensitivity. However, when the width is further decreased, the MI ratio drops considerably due to flux leakage through the inner conductor. This effect was analyzed within a 2-D model of a three-layer symmetrical film system, having magnetically open-loop structure, giving a reasonable agreement with the experimental results in 50 and 20 [micro]m wide films. Index Terms--Flux leakage, head efficiency, magnetoimpedance sensors, thin films, transverse anisotropy.

Magnetoelastic thin films are applied in remote interrogatable high-frequency devices. Integrated LC circuits operating at a frequency of 350 MHz are demonstrated. Due to the incorporation of the magnetic thin films, their inductance is sensitive to the applied external stress. A demonstrator was built, allowing a visualization of the effect of tensile and compressive strain on the device response. A comparison of the demonstrator measurement with high-frequency properties and the domain structure of the magnetoelastic layer proves an efficient integration of the magnetic material. The differences between predicted and measured device performance are related to an additional local stress distribution inside the magnetic device thus leading to an inhomogeneous stress and a locally varying magnetic anisotropy distribution. The investigations are essential for future applications of the devices as strain gauges or torque sensors. Index Terms--Domains, ferromagnetism, high frequency, permeability.

An InSb thin-film linear micro-Hall sensor array of eight sensors, each with a sensitivity of 10 nT/[Hz.sup.1/2] was developed for biomedical applications. The individual Hall sensors had an active area of 5 [micro]m x 5 [micro]m and were separated by a distance of 5 [micro]m. A combination of these Hall devices and a magnetization system incorporating both dc and ac bias magnetic fields, enabled the simultaneous detection of multiple 2.8 [micro]m diameter superparamagnetic beads. Index Terms--Hall effect devices, magnetic particles, magnetic sensors, nanostructure materials.

In order to fabricate the thick ferrite films, electrophoretic deposition (EPD) of Ni-Zn ferrite fine particles in water dispersion mixtures was carried out at room temperature. It is shown that densely packed ferrite films with a thickness of 12 [micro]m can be deposited via EPD at high deposition rate of 400 nm/min from fine particles with a size of 10-30 nm onto an ITO glass substrate. The particulate film exhibited soft magnetic properties almost the same as raw particles. Index Terms--Electrophoretic deposition (EPD), Ni-Zn ferrite, particulate film, ultra fine particle.

In-plane and out-of-plane ferromagnetic resonance measurements were performed on arrays of Permalloy rectangles, prepared by interference lithography. In the absence of crystalline anisotropy, the shape anisotropy dominates the angular dependence of the resonance and the linewidth. The 60-70-mT in-plane anisotropy follows the increase of the aspect ratio. The uniaxial out-of-plane anisotropy fields are on the order of 500 mT. The linewidth has a strong angular dependence, both in the in- and out-of-plane rotation, ranging from about 17 to 23 mT along the easy and hard axes and decreasing with increasing shape anisotropy. Two distinct resonance modes observed in the perpendicular orientation are associated with the main volume mode and shape mode of magnetostatic origin. Index Terms--Magnetic anisotropy, magnetic resonance, patterned thin films, Permalloy.

Vortex nucleation and vortex motion are the main mechanisms of magnetization reversal in micrometer-sized magnetic elements. The critical field required to nucleate a vortex depends on the temperature. We propose a method that combines standard Landau-Lifshitz-Gilbert (LLG) micromagnetics and an elastic band method to simulate nonzero temperature hysteresis curves of magnetic thin film elements. Whereas the LLG simulations gives the equilibriums states before and after a vortex enters the element, the elastic band method gives the height of the energy barrier between these two states. Thus temperature-dependent nucleation fields can be computed without the need to perform stochastic LLG simulations. Index Terms--Energy barrier, magnetization reversal, micromagnetics.

We have proposed a method for identifying a wide-band equivalent circuit model for ferromagnetic radio frequency (RF) integrated inductors. The equivalent circuit parameters have been extracted from measured S-parameters by using a multiobjective simplex method, which sequentially switches three different cost functions, given by the average of error in Y-parameters, Z-parameters, and S-parameters. With this method, the optimization converged to the global minimum without being trapped at a local minimum. Calculated Y-parameters, Z-parameters, and S-parameters were in good agreement with the measured results in the range of de to 20 GHz. Index Terms--Circuit optimization, equivalent circuits, ferromagnetic materials, scattering parameters, thin-film inductors.

We have investigated the microwave properties of a set of Co-Fe-Al-O films with different thicknesses. The films show a well-defined in-plane anisotropy due to the bias field applied during deposition. The resonance frequency is determined through the scattering parameters measured with a vector network analyzer and a probing station connected to a coplanar waveguide. The results show that the resonance peak features depend on the direction of the applied/RF field and on the applied field history. Index Terms--Anisotropy, FeCo films, ferromagnetic resonance, magnetic thin films, microwave properties, nanogranular films.

This paper investigates the switching behavior of magnetostrictive micro-dot arrays by mechanical strain. These amorphous FeCoBSi micro-dot arrays with diameters of 1-5 [micro]m and a thickness of 20 nm have been prepared on MEMS fabricated membrane structures. Magnetic force microscopy (MFM) has been used to obtain a spatially resolved switching behavior of these dots at different level of mechanical strain. For 20-nm-thick FeCoBSi dots, we have observed a strain induced switching starting at a level of about 0.04% of strain. In addition, finite-element simulations have been performed in order to correlate the MFM results with the local strain distribution of the membrane structure. Index Terms--Magnetostriction, micro-fabrication, strain sensors, thin films.

We previously revealed that spin sprayed Ni-Zn ferrite films had a weak in-plane uniaxial magnetic anisotropy induced parallel to the liquid flow direction during the spin spraying. Adding a small amount of Co to the films, we made the uniaxial magnetic anisotropy definitely strong. The imaginary part of the complex permeability ([mu] = [mu] - j[mu]') of the Co-containing films measured in the remanence state exhibited a dual step-like dispersion. In order to reveal the influence of magnetic anisotropy of the films on the magnetic resonance, we deposited, in this study, films #1 ([Ni.sub.0.17][Zn.sub.0.22][Fe.sub.2.61][O.sub.4]) and #2 ([Ni.sub.0.19][Zn.sub.0.20][Co.sub.0.03][Fe.sub.2.58][O.sub.4]) by spin spray ferrite plating at 90[degrees]C. The imaginary permeability in the remanence state of the film #1 (which exhibited no definite in-plane magnetic anisotropy) had a maximum at about 450 MHz, which increased with increasing external dc magnetic field, [H.sub.dc] in the range of 1-3 GHz to give a similar spectrum to that of the film #2. The resonance field, [H.sub.R] of the film #2 under [H.sub.dc] of 1-2 kOe, which was strong enough to saturate the magnetization, exhibited a prominent in-plane angular dependence, while [H.sub.R] of the film #1 exhibited a very weak angular dependence. The difference between the maximum and the minimum values of [H.sub.R] for the film #2 was about 60 Oe. This means that the film #2 consists of two regions, one with a crystalline anisotropy field having an in-plane isotropic distribution due to the cubic spinel structure, and the other with an induced uniaxial anisotropy field, [H.sub.k] of about 60 Oe. Assigning [H.sub.k] of 60 Oe, we calculated the natural resonance frequency, [f.sub.r] as 1.6 GHz. This value approximately coincided with that of the higher frequency step of [mu]' for the film #2 in the remanence state. This suggests that the magnetic loss in the remanence state for the films like #2 (which exhibit prominent uniaxial anisotropy induced in film plane) is ascribed to the two regions described above. Index Terms--Complex permeability, ferrite plating, ferromagnetic resonance (FMR), Ni-Zn(-Co) ferrite film.

xFe/(100-x)(NiZnCu)[Fe.sub.2][O.sub.4] (x: wt%) composite films were prepared by the aerosol deposition (AD) method. The as-deposited x = 80 film exhibited the maximum relative permeability of [[mu]'.sub.r max] = 18 at around 450 MHz. The AD film also showed [[mu]'.sub.r] = 9 at 3 GHz, which were comparable to the values obtained with a heat-treated NiZnCu ferrite AD film. The result of transmission and reflection measurements revealed that these composite films have high potential for noise suppressors in the gigahertz range. In particular, the maximum of pure power loss ([DELTA] [P.sub.loss]/[P.sub.in]) of 0.68 have been obtained in the x = 4 film. Index Terms--Aerosol deposition method, composite film, ferrite, noise suppression, permeability.

A new type of oxide composite film was proposed as perpendicular magnetic recording medium. The storage layer is composed of Co-Pt and Ti-oxide. By transmission electron microscopy (TEM) observation, the film exhibited a well isolated fine granular structure with small and uniform Co-Pt grains surrounded by Ti[O.sub.2]. More sufficient segregation by Ti[O.sub.2] was realized from the beginning of the layer growth compared with other oxide addition film, resulting in a magnetically weak coupled structure. This film has a relatively large magnetic anisotropy constant ([K.sub.u]) and saturation nmgnetization ([M.sub.s]) of more than 5 x [10.sup.6] erg/[cm.sup.3] and about 800 emu/[cm.sup.3], respectively. The structure was brought about by a high sputtering gas pressure of Co-Pt-Ti[O.sub.2] film deposition. Index Terms--Film microstructure, perpendicular anisotropy, perpendicular magnetic recording medium, sputtered thin film.

[Ni.sub.2]MnGe alloy films were fabricated by flash-evaporation. A wide substrate temperature range (from 150 to 730 K) was chosen to prepare the alloy films with significantly different atomic orders. Various physical properties, including the magnetic, the optical, and the magnetooptical properties, were investigated. It was shown that the [Ni.sub.2]MnGe alloy film with an [L2.sub.1]-type structural order has been successfully fabricated. The ordered films exhibit the physical properties close to the corresponding bulk alloy. Unexpectedly, the disordered alloy films are not ferromagnetically ordered. These results were further analyzed in connection with the electronic structures of the alloy. Index Terms--Heusler alloy films, magnetic properties, Ni-Mn-Ge, optical properties.

Using molecular dynamics simulation, the morphology of Ni thin film growth on Ni(111) substrate according to the incident energy of adatoms was investigated. Ni atoms apparently favored the island growth mode at low incident energy. The growth mode of Ni film was, however, changed to follow layer-by-layer growth mode for the incident energy of 6 eV. The steering effect due to atomic attraction, which results in rougher surface, was significantly observed at low incident energy. The local acceleration for the corresponding steering effect was quantitatively calculated. Index Terms--Growth morphology, molecular dynamics simulation, Ni/Ni(111), steering effect.

Nanogranular films of composition [Ag.sub.100-x][Fe.sub.x] (x: 10, 14, 20, 26, 30 at %) were prepared by dc plasma sputtering deposition. All films exhibit a negative magnetoresistance whose intensity decreases monotonically with temperature, with no apparent saturation up to 50 kOe. A magnetic correlation range [R.sub.m] is obtained from analysis of the GMR versus M/[M.sub.S] curves. The role of interparticle correlation is investigated as a function of both Fe concentration and temperature. Index Terms--Correlations, magnetoresistance, thin films.

Ag submicrometer pyramidal islands with a (100) truncated top and four (111) sidewalls were successfully fabricated on Si(100) substrates at a deposition temperature of 500 [degrees]C. The magnetization reversal of 30 nm thick Fe films grown on Ag pyramidal islands was studied by magnetic force microscopy. The magnetization reversal of Fe films was first started at the sidewalls of pyramidal islands. Then, the formation and propagation of wall-like structures were observed under a higher external magnetic field, namely 95 Oe. The magnetic domain images indicated that the Fe films grown on the sidewalls of pyramidal islands and the strength of external field played important roles on the magnetization reversal of Fe films. Index Terms--Iron films, magnetization reversal, silver pyramidal islands.

The microstructure, magnetic, and electrical properties of as-sputtered annealed nanostructured [Fe.sub.50][Ni.sub.50] films have been studied. The magnetic and electrical properties were used to assess the degree of magnetic ordering. Long-time low-temperature anneals cause both phase separation and ordering in this alloy. However, a fully L[1.sub.o]-ordered structure could not be obtained even after annealing at 280 [degrees]C for 1 week. Index Terms--[Fe.sub.50][Ni.sub.50], magnetic ordering, nanostructured films, thermal annealing.

Epitaxial thin films of AB[O.sub.3] (A = Ca, Sr; B = 3d, 4d transition metal) were fabricated on a (100)-SrTi[O.sub.3] substrate by spin coating an organic metal and subjecting it to successive heal treatments. Results of X-ray diffraction and transmission electron microscopy indicate that the growth is pseudomorphic and the [001] axis of the AB[O.sub.3] film is perpendicular to the (100) plane of the SrTi[O.sub.3] substrate and that its pseudocubic axes align parallel to the cubic axes of the SrTi[O.sub.3] crystal. Epitaxial AB[O.sub.3] thin films have similar transport and magnetic properties to those of bulk materials. Index Terms--Coatings, epitaxial growth, sol-gel, transition metal oxides.

Magnetic reversal behaviors of Au (60 nm)-FePt (x nm) thin films with various x values are investigated. A high temperature heat treatment at 800[degrees]C was applied to obtain an isolated microstructure with L[1.sub.0] FePt particles embedded in a face-centered cubic gold matrix through interracial diffusion. The coercivity of the thin films was increased from 13.6 kOe to a maximum value of 30.0 kOe as the thickness of the FePt layer was decreased from 200 to 10 nm. From the dc demagnetization and isothermal remanence magnetization measurements, we found that the bilayer sample with x = 10 exhibits larger reversible magnetization. The coercive mechanism was found to be controlled by the magnetization rotation of the isolated FePt particles. As x is increased, the reversal behavior is changed into a domain-wall motion mode gradually. The magnetic force microscopy investigations further confirm the change of mechanism. The domain-wall motion appears to result from the formation of large multidomain grains. Considering the relation of reversal behavior and the coercivity, we thus conclude that the removal of domain walls is beneficial for hard magnetic performance. Index Terms--Bilayer thin films, coercivity enhancement, domain structure, domain-wall motion, FePt, magnetic reversal behavior, magnetization rotation.

The face-centered-tetragonal granular L[1.sub.0] FePt nanoparticles with large in-plane coercivity ([H.sub.//]) of about 3923 Oe can be achieved by an Ag-capped layer of 5-nm thickness deposited onto the FePt magnetic layer, with thickness of 20 nm, after annealing at 400[degrees]C for 30 min. The perpendicular coercivity ([Hc.sub.[perpendicular to]]) of the films is increased by increasing the annealing temperature ([T.sub.s]), and the [Hc.sub.[perpendicular to]] value is about equal to the [H.sub.//] value when the annealing temperature is increased to 600[degrees]C. TEM-energy disperse spectrum analysis reveals that the Ag mainly distributed at the grain boundary of FePt and results in the isolation of the FePt grains as well as the increase of the grain boundary energy, which will enhance coercivity and change the preferred orientation of the FePt film. Index Terms--Ag-capped layer, coercivity, FePt-Ag multilayer films, magnetron sputtering.

L[1.sub.0] phase FePt thin films deposited on amorphous Corning glasses and single crystal MgO (100) substrates were investigated. Epitaxial growth of the FePt (001) films was observed on MgO substrate at a deposition temperature of 400[degrees]C. With ultrathin Ag intermediate layers deposited between FePt layers, the film structure changed from interconnection network to isolated-island character. The perpendicular coercivity of the FePt film increased to about 32 kOe with intermediate layers inserted. The improvement of the magnetic properties may be attributed to the formation of island structures by the additive Ag layers in the FePt films. Index Terms--Ag, epitaxial growth, FePt, high coercivity, intermediate layer, MgO, perpendicular magnetic recording.