• Journal of Magnetics
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• v.22 no.1
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• pp.49-54
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• 2017

The significant reduction of the image quality caused by the magnetic field of samples is a major problem affecting the application of SEM (scanning electron microscopy) in the analysis of electronic devices. The main reason for this is that the electron trajectory is deflected by the Lorentz force. The usual solution to this problem is degaussing the sample at high temperatures. However, due to the poor heat resistance of some electronic components, it is imperative to find a method that can reduce the impact of magnetic field on the image quality and is straightforward and easy to operate without destroying the sample. In this paper, the influence of different magnetic field directions on the imaging quality was discussed by combining the experiment and software simulation. The principle of the method was studied, and the best observation direction was obtained.

• Journal of the Korean Ceramic Society
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• v.43 no.11 s.294
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• pp.703-709
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• 2006

We report on the synthesis of highly uniform, single phase zinc and cobalt thin films prepared by the Liquid Phase Deposition (LPD) method. X-Ray diffraction, TGA and EDX measurements support the assumption that the as deposited films are constituted by a mixture of crystallized FeOOH and amorphous M(OH)$_2$ (M=Co, Zn) which is converted upon heat treatment in air at 600?C into the corresponding zinc ferrites. The films with adjustable chemical compositions are identified with a crystal structure as spinel-type and present a spherical or rod-like microstructure, depending on the both the nature and concentration of the divalent transition metal ions. Zinc ferrite thin films present a superparamagnetic behavior above blocking temperatures which decrease with increasing the Zn content and are ferromagnetic at 5 K with coercivities ranging between 797.8 and 948.5 Oe, whereas the cobalt ferrite films are ferromagnetic at room temperature with magnetic characteristics strongly dependent on the chemical composition.

• Proceedings of the Korean Magnestics Society Conference
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• 2000.09a
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• pp.337-345
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• 2000

The spontaneous Hall effect in amorphous Tb-Fe and Sm-Fe thin films, which possess excellent magnetic softness, is investigated in this work to seek a possibility of practical applications of these thin films as sensors. The resistivity of Tb-Fe thin films ranges from 180 to 250 Ωcm as the Tb content varies from 35 to 46 at. %. Tb-Fe thin films show negative Hall resistivity ranging from - 7.3 to - 5.0 Ωcm in the same composition range, giving the normalized resistivity ratio in the range of -4.1 to -2.0 %. On the other hand, the resistivity of Sm-Fe thin films ranges from 150 to 166 Ωcm as the Sm content varies from 22 to 31 at. %. Sm-Fe thin films show positive Hall resistivity which varies from 7.1 to 2.8 Ωcm in the same composition range, giving the normalized resistivity ratio in the range of 4.8 to 1.7 %. These values are significantly high compared with the values of other R-T alloys, Tb-Co alloys for example, where the highest reported value is 2.5 %. Between the two different sets of samples, Tb-Fe thin films with perpendicular anisotropy are considered to be more suitable for practical applications, since saturation is reached at a los magnetic field, approximately 2 kOe in a Tb$\sub$35.1/ Fe$\sub$64.9/ thin film, for example.

• Proceedings of the KIEE Conference
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• 1998.07d
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• pp.1279-1281
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• 1998

The Co-Cr thin films are one of the most suitable candidates for perpendicular magnetic recording media. The facing targets sputtering(FTS) method has a advantage of preparing films over a wide range of working gas pressure on plasma-free substrates. In this study, we investigated the possibility of employing FTS system for depositing Co-Cr films, Co-Cr thin films were deposited with continuously sputter gas pressure ($P_{Ar}$ = 0.1 mTorr) by FTS method at temperature of $40^{\circ}C$. We find that the change of thickness and deposition rate of sputtered Co-Cr thin films affect crystal orientation and magnetic properties. Crystallographic and magnetic properties were evaluated by x-ray diffractometry(XRD) and vibrating sample magnetometer(VSM) respectively. It has been confirmed that the FTS method is very useful for preparing Co-Cr thin film recording media.

• Journal of Magnetics
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• v.17 no.2
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• pp.78-82
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• 2012

CoNiFe(CNF)/$BaTiO_3(BTO)$/CoNiFe(CNF) multilayered thin films were deposited on Pt/Ti/$SiO_2$/Si substrates by using pulsed laser deposition (PLD) system. We fabricated three different thin films of BTO, BTO/CNF and CNF/BTO/CNF for magneto-capacitor and studied their crystalline structure, surface and interface morphology, and magnetic and electrical properties. When three different structures of multilayered thin film were compared, magnetization of CNF/BTO/CNF thin films was decreased by magnetic and dielectric interaction. Also we confirmed that capacitance of CNF/BTO/CNF multilayered thin film was enhanced as being near tetragonal structure with increasing of c/a ratio because of atomic bonding at interface between BTO dielectric and CNF magnetic materials. Finally, we studied the change of the capacitance of CNF/BTO/CNF multilayered thin film with magnetic field for emergence of magnetocapacitance and suggested a possibility of enhanced capacitance.

• Journal of the Korean Ceramic Society
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• v.32 no.3
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• pp.313-320
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• 1995

We investigated the preferred orientation, electrical and magnetic properties of the Mn-Zn ferrite thin films deposited on SiO2/Si(100) by ion beam sputtering. The Cu-added Mn-Zn ferrite thin films had a preferred orientation of (111) with a weak orientation, (311). While the Zn-added one had a strong (111) preferred orientation. The saturation magnetization of the Cu- or Zn-doped Mn-Zn ferrite films increased with increasing substrate temperature (Ts) due to the increase of grain size and the enhancement of crystallinity. For the same reason the coercivity of Cu- or Zn-doped Mn-Zn ferrite films deposited at low Ts increased with increasing Ts, but those of the films deposited at high Ts slightly decreased not only because the defect density of the films decreases but because more grains have multi-domains with increasing Ts. The resistivity of Cu- or Zn-added Mn-Zn ferrite thin fims measured by complex impedance method decreased with increasing Ts due to the ehhancement of crystallinity as well as due to the increase of grain size.

• Proceedings of the KIEE Conference
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• 1997.07d
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• pp.1379-1382
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• 1997

Diamond-like carbon(DLC) thin films are produced by using a filtered cathodic vacuum arc(FCVA) deposition system. Different magnetic components, namely steering, focusing, and filtering plasma-optic systems, are used to achieve a stable arc plasma and to prevent the macroparticles from incorporating into the deposited films. Effects of magnetic fields on plasma behavior and film deposition are examined. The carbon ion energy is found to be varied by applying a negative (accelerating) substrate bias voltage. The deposition rate of DLC films is dependent upon magnetic field as well as substrate bias voltage and at a nominal deposition condition is about $2{\AA}/s$. The structural properties of DLC films, such as internal stress, relative fraction of tetrahedral($sp^3$) bonds, and surface roughness have also been characterized as a function of substrate bias voltages and partial gas($N_2$) pressures.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1994.11a
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• pp.190-191
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• 1994

In this paper, We study on the fabrication of amorphous this film of zeromagnetostriction material and the magnetic properties. This films are fabricated by using sputtering method with input power of 400∼607[W], Ar gas pressure of 3∼ 9[mTorr] and target composition of Fe$\sub$4.7/ Co$\sub$74.3/Si$_2$B$\sub$19/. Sample this films with diameter of 14[mm ] and thickness of 27-30[$\mu\textrm{m}$] were obtained through experiments. When we analyzed the magnetic properties before and after annealing with sample thin films, we confirmed that magnetic domain wall amorphous thin films consisted for Neel magnetic domain wall with the width of about 1[$\mu\textrm{m}$].

• Korean Journal of Metals and Materials
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• v.50 no.3
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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.

• Journal of Magnetics
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• v.17 no.4
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• pp.233-241
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• 2012

In this work, Monte Carlo simulation was used to investigate the magnetization properties of thin ferromagnetic films under a perturbation from a supplied heat pulse on one surface of the films. The finite difference method was used to extract the local temperature of each layer of the films as a function of time for various heat source power and heating period. Then, with the variation of the films temperature, Metropolis method was used to update the magnetic moment in magnetic grain, under the Ising framework and using the FePt parameters. With the extracted magnetization profiles, the relationship between magnetization relaxation in accordance with relevant heat parameters and films thickness was reported and discussed, with a purpose to form a database for future use.