• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 한국전기전자재료학회 2000년도 추계학술대회 논문집
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• pp.459-462
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• 2000

A new method for the fabrication of poly-Si films is reported using by alternating magnetic flux crystallization (AMFC) of LPCVD a-Si films. In this work we have studied the crystallization of LPCVD a-Si films by alternating magnetic flux. A-Si films were 1200$\AA$-thick deposited at 48$0^{\circ}C$ at a total pressure of 0.25Torr using Si$_2$H$_{6}$/H$_2$. After this step, these a-Si films were thermally annealed by Alternating Magnetic Flux at 43$0^{\circ}C$ for 1hours. The annealed films were characterized using X-ray diffraction (XRD), Raman Spectra, Atomic Force Microscopy(AFM). Both alternating magnetic flux crystallization and solid phase crystallization were investigated to compare enhanced crystallization a-Si. We have found that the low temperature crystallization method at 43$0^{\circ}C$ by alternating magnetic flux.x.

• Journal of Magnetics
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• 제7권2호
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• pp.45-50
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• 2002

A magnetic field annealing is firstly used for nanostructured Sm-Co/Co films, prepared by magnetron sputtering method. The effects of magnetic field annealing on single-layered Sm-Co films are different from those on multi-layered Sm-Co/Co films. A detailed analysis of microstructures and magnetic properties is made by means of HRTEM, Auger electron spectroscopy, XRD and Physical Property Measurement System (PPMS). From magnetic properties and microstructure analysis, it was confirmed that these differences originate from the effects of magnetic field annealing on crystallization behavior of the films. The relationship between magnetic properties and microstructures explains a different demagnetization process of single-layered and multilayered films. For the single-layered Sm-Co films, magnetic-field-annealing makes the main phases change from $CaCu_5/ to Zn_2Th_{17}$ structure, resulting in a decrease of coercivity. The results show that the magnetic-field-annealing is useful to improve the properties of nanostructured Sm-Co(30 nm)/Co(10 nm) films, which ascribe to improving the pinning effectiveness in coercivity mechanism and decreasing the magnetostatic interaction of films. A very high coercivity about 0.7 T was obtained from nanoscaled multi-layered Sm-Co(30 nm)-/Co(10 nm) films.

• Applied Science and Convergence Technology
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• 제27권1호
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• pp.1-4
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• 2018

A sputtering-assisted magnetic field system was successfully developed for depositing crystalline Cu thin films at room temperature. This system employs a plasma source and an ion-beam gun with two magnetic field generators, which is covered with sputtering target and the ion-beam gun, simultaneously serving as sputtering plasma and a magnetic field generator. The formation of crystalline Cu thin films at room temperature was dominated by magnetic fields, which was revealed by preliminary experiments. This system can be employed for producing crystalline metal thin films at room temperature.

• Journal of the Korean institute of surface engineering
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• 제26권2호
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• pp.45-54
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• 1993

In this study, magnetic properties of anodized Al film deposited with ferro-magnetic metals in the capacity of perpendicular magnetic recording media were measured and evaluated to find out the role of structure and morphology of the oxide films on magnetic characteristics. The object of this work was to present the conditions of magnetic thin film formation with more superior magnetic property. Anodizing was carried out under various conditions, and then the anodized film were electro-deposited with Co, Ni, Fe and their alloys. Coercive force and residual magnetization in perpendicular direction increased as the pore length of anodized film increased. It was attributed to the increase of the amount of depoisted metals and the ratio of length/diameter of pores. Morphology of anodized films in phosperic acid was not similar to that of sulfuric acid, and thin films in the former solution had perpendcular magnetic anisostropy because of large diameter, irregular length and distribution of the pores. It was found that magnetic properties of the thin films, which had doubled layer of two metals, were dominated by the metal electrodeposited on the surface of the anodized oxide films.

• Journal of Magnetics
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• 제6권1호
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• pp.9-12
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• 2001

The dependence of the magnetoimpedance effect (MI) on magnetic properties has been investigated in mumetal thin films prepared by rf magnetron sputtering. Coercivity of thin films prepared at 400 W was about 0.4 Oe, and the magnetic anisotropy field of films deposited under a uniaxial magnetic field decreased with increasing film thickness. The saturation magnetization of mumetal films increased with rising input power and thickness and was smaller than that of permalloy films. Transverse incremental Permeability (TPR) of films of 1$\mu m$ thick increased with increasing effective permeability. The magneto impedance ratio (MIR) was proportional to TPR in films 1$\mu m$ thick but in spite of lower effective permeability at higher thicknesses, MIR increased due to skin effect. The height of the double peaks in the MIR curves decreased with decreasing anisotropy and thickness. The maximum MIR value for a 4$\mu m$ thick 75% at 36.5 MHz.

• Journal of Magnetics
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• 제16권4호
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• pp.403-407
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• 2011

Metal-insulator type, nano-granular soft magnetic films have been reviewed from the viewpoint of high frequency magnetic materials. The formation of nano-granular structure is related to the magnitude of heat of formation of intergranule materials. Variation of the ratio of granule phase to intergranule phase in the film is found to produce various characteristics in the magnetic properties of the film. The HRTEM observation reveals that neighboring granules in the film with above 60 at.% Co, contact at considerable points and the films show soft magnetic properties which are explainable in terms of the random anisotropy model for nano-crystalline materials. Addition of Ni group elements in Co-O based films enhances their anisotropy field up to 400 Oe and they exhibit excellent frequency response of permeability. Also, large electromagnetic noise suppression effect is demonstrated as one of their potential applications.

• Journal of Magnetics
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• 제6권2호
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• pp.73-76
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• 2001

A double rectangular spiral type inductor has been fabricated by using FeTaN films. The inductor is composed of internal coils sandwiched by magnetic layers. Characteristics of inductor performance are investigated with an emphasis on planarization of magnetic films. In the absence of the planarization process, the grating topology of the upper magnetic films over the coil arrays degrades the soft magnetic properties and the inductor performance. It also induces a longitudinal magnetic anisotropy with the easy axis aligned to the magnetic flux direction. This alignment prevents the upper magnetic films from contributing to the total induction. Glass bonding is a viable method for achieving a completely planar inductor structure. The planar inductor with glass bonding shows excellent performance: inductance of 1.1 $\mu H$, Q factor of 7 (at 5 MHz), and the current capability up to 100 mA.

• Korean Journal of Metals and Materials
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• 제50권3호
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• pp.248-255
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• 2012

AlN thin films containing various amounts of Co, AlN-Co, and Al-Co alloy particles were prepared using a two-facing-target type dc reactive sputtering (TFTS) system. The as-deposited films exhibited the variable nature expected from an AlN-rich phase, and an amorphous-like phase, depending on the Co content in the films. Specific favorable microstructures were prepared by optimizing annealing conditions. Those microstructures and their magnetic properties and resistivity were investigated. As-deposited films showed very small saturation magnetization and an amorphous-like structure. However, when annealed, the as-deposited amorphous-like phase decomposes into phases of AlN, Co and Al-Co. These annealing induced changes in the microstructure improve the magnetization and resistivity of the films. Further improvement of soft magnetic properties could lead to the material being used for high density magnetic recording head material.

• Korean Journal of Materials Research
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• 제4권5호
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• pp.581-589
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• 1994

Magnetic properties and microstructures of the $Co_{83}Cr_{17}$ films growing under the applied magnetic field were studied. In comparison, those of the films growing without magnetic field were also studied. Magnetic field does not affect saturation magnetization and in-plane coercivity of the films. On the contrary perpendicular coercivity and effective perpendicular anisotropy field decreased. Grain size and the thickness of the so-called transition layer were not affected and the C-axis alignment of the films was slightly deteriorated due to magnetic field. Also, microstructures of the sputtered films showed larger grain sizes of strong (002) preferred orientation for thicker film specimens independent of applied magnetic field.

• Journal of Magnetics
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• 제13권2호
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• pp.57-60
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• 2008

This study examined the effect of various types of epitaxial strain on the magnetic properties of $SrRuO_3$ thin films. Epitaxial $SrTiO_3$ (001), $SrTiO_3$ (110), and $SrTiO_3$ (111) substrates were used to apply different crystal symmetries to the grown films. The films were grown using pulsed laser deposition. The X-ray diffraction patterns of the films grown under optimum conditions showed very clear peaks for the $SrRuO_3$ film and $SrTiO_3$ substrates. The saturated magnetic moment at 5 K after 7 Tesla field cooling was $1.2-1.4\;{\mu}_B$/Ru. The magnetic easy axis for all three types of films was along the surface normal. The magnetic transition temperature for the $SrRuO_3$ film with lower symmetry was slightly larger than the $SrRuO_3$ film with higher symmetry.