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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of the Korean Magnetics Society
Journal Basic Information
Journal DOI :
The Korean Magnetics Society
Editor in Chief :
Volume & Issues
Volume 4, Issue 4 - Dec 1994
Volume 4, Issue 3 - Sep 1994
Volume 4, Issue 2 - Apr 1994
Volume 4, Issue 1 - Mar 1994
Selecting the target year
Measurement of the Magnetostrictive Properties of Giant Magnetostrictive Alloy
Journal of the Korean Magnetics Society, volume 4, issue 4, 1994, Pages 303~306
Fundamental characteristics of giant magnetostrictive alloy
are rreasured and discussed on the application for actuators. The magnetostriction is measured by laser displacement rreasuring system and the applied compressive stress is measured by load cell. Magnetostrictions increased as the applied compressive stresses increased. When the stress is 7 MPa, the magnetostriction is 1000 ppm at 1500 Oe. As the stresses iocreased from 0 to 14 MPa, the magnetic fields for saturating the magnetostriction also increased. The temperature increased during the experiment is
, so the thermal expansion is negligible in these experirrents. The feedback or temperature control function should be added for the precise position control actuator.
Analysis for the magneto-optical Kerr effect of metal multilayers by optical multiple reflection
Journal of the Korean Magnetics Society, volume 4, issue 4, 1994, Pages 307~312
The magneto-optical Kerr effect due to the (Fe,Co)/(Pd,Pt,Cu,Ag) multilayer film is calculated considering of multiple reflection effect, and the calculated Kerr spectrum is compared to the reported experimental value. In case of Co/Pd, the reliance of composition and the variable tendency of magneto-optical Kerr rotation angle for Co thickness fully coresponds to experimantal and theoretical value. The theoretical Kerr spectrum of Fe/Cu and Fe/Ag multilayer films show the peaks near the Cu and Ag optical ansorption band in accordance with the experiment. But in case of Co/Pt, the increase tendency of Kerr rofation with decreasing wavelength reported by experiments could not be explained by the optical multiple interference. This difference of theoretical and experimental Kerr spectrum of Co/Pt film might be related with the change of electronic structure of Co and/or Pt from their bulk state.
Dependence of Magnetic and Magneto-Optic Properties on Deposition Angle in E-Beam EVaporated Co/Pt Multilayer Films
Journal of the Korean Magnetics Society, volume 4, issue 4, 1994, Pages 313~318
We have investigated the effects of deposition angle on magnetic and magneto-optic properties in Co/Pt multilayer thin films. which were prepared bye-beam evaporation on tilted substrates. with varying tilt angle from
. The structure of the specimens was examined by x-ray diffractometer and scanning electron microscope. and the magnetic and magneto-optical properties were measured by VSM, torque magnetometer, and Kerr loop tracer. X-ray diffractometry revealed that all of the specimens had multilayer structure and growth orientation of column followed the tangent rule but the crystallograpic orientation, <111>, was slightly deviated from the substrate normal even though the deposition angle was increased up to
. A decrement of the magnetization and Kerr angle with the deposition angle was related with that of the film density due to increasing porosity. The perpendicular mag¬netic anisotropy was also decreased with increasing the deposition angle.
Influence of Target Manufacturing Condition on the Coercive Force and Effective Permeability of Permalloy
Journal of the Korean Magnetics Society, volume 4, issue 4, 1994, Pages 319~325
Permalloy films were deposited by an RF magnetron sputtering method using several different targets which had been cold-rolled and annealed at various temperatures to give different microstructure and texture. The grain refinement occurs at high temperature annealing due to recrystallization and subsequently the initial (110) target texture transforms to the random texture. The coercive forces of thin films fabricated using targets which are not recrystallized are below 0.2 Oe in the AI pressure range of 1~5 mTorr and the lowest coercive force achieved is 0.07 Oe. The low value of coercive force, 0.25 Oe, is only obtained at the sputtering conditions of 400 W and 1 mTorr, and 300 W and 5 mTorr when recrystallized targets are used. The internal stress changes from compressive to tensile as the Ar pressure increases, the stress-free being at 5 mTorr. The changes of coercive force and permeability can be well interpreted by the differences from the composition and the internal stress.
A Study on the Fabrication of Oil Seal Appartus by use of the Magnetite Magnetic Fluid
Journal of the Korean Magnetics Society, volume 4, issue 4, 1994, Pages 326~334
This paper describes the fabrication of the hydrophilic magnetic fluid with high viscosity and its application to oil seal apparatus used with the Nd-permanent magnet. The results are as follows. 1) The ultrafine magnetite particles under the size of
are first coated by the oleic acid ion and again adsorbed by the hydrophilic D. B. S. ion, and there by hydrophilic magnetic fluid with high viscosity could be made by dispersing them into the ethylene glycol. 2) In development of the oil seal apparatus using magnetic fluid and Nd-permanent magnet, the viscosity and magnetic susceptibility show high when the
content is over 50%(g/cc) in the fluid, so that such properties could improve highly the capability of oil seal. 3) The maximum of the resisting pressure of the oil seal using the ethylene glycol base magnetic fluid and the Nd-permanent magnet, is about
, under the condition of this experiment. Therefore the oil seal may not be suitable for the ship engine and the driving part of the automobile, and thus it needs a lot further complementary reserch. However, it is quite favourable for such an oil seal apparatus as speed reducer under the condition of atmospheric pressure.
The Crystallograpic and Magnetic Properties of EuFeO3 Doped with in ions
Journal of the Korean Magnetics Society, volume 4, issue 4, 1994, Pages 335~339
The crystallograpic and magnetic properties of
(x=0, 0.03과 0.05) have been studied by the methods of X-ray diffraction,
spectroscopy, and magnetic hysteresis measurement at room temperature. The X-ray results show that the samples have a crystal structure of orthorhombic and unit cell volume of the crystal with the exception of the sample of x=0 increases as increasing the In concentration. In the analysis assuming two sets of six-line of
spectra, it is found that the magnetic hyperfine field in each of sets decreases increasing x. The linewidth of the absorption lines for the samples increased as increasing x. This implies that the data involve a sum of several hyperfine patterns which have intensity being proportional to
, the probability of an environment with z such Fe neighbors. The magnetic hysteresis curves show decrease of
and increase of
of the samples with increasing x.
Giant Magnetoresistance Phenomenon under the Double Magnetic Fields
Journal of the Korean Magnetics Society, volume 4, issue 4, 1994, Pages 340~346
Change in the electrical resistance of artificial superlattice under two magnetic fields-the main and the secondary magnetic field-has been studied with respect to each magnetic field strength in (200) textured Co/Cu artificial superlattice. When the two magnetic fields were applied in the same direction, lateral shift of the magnetoresistance curve occurred, while splitting phenomenon of the maximum resistance appeared when the two magnetic fields were applied at the right angle. When the angle between the two magnetic fields became
shifting as well as splitting occurred in the magnetoresistance curve. This magnetoresistance behavior with double magnetic fields in the artificial superlattices could be explained with the macroscopic spin alignment model newly suggested in this work.
New Magnetic Phases of Fe-N and Mn-Al Alloys Produced by Mechanochemical Milling
Kyu-Jin Kim ; Tae-Hwan Noh ; Kenji Suzuki ;
Journal of the Korean Magnetics Society, volume 4, issue 4, 1994, Pages 347~354
The structural change and magnetic properties of mechanically milled Fe-N and Mn-Al alloy powders have been investigated by XRD, TEM, VSM,
spectroscopy and inelastic neutron scattering measurements. During milling of
powders, and fcc
phase is transformed to a bct
phase by stress-induced martensitic transformation, being accompanied by an initial increase in saturation magnetization. During annealing the bct
nanocrystalline phase which is obtained by mechanical grinding for a long time, an
phase partially appears as an intermediate phase at 673~773 K, causing an increase in saturation magnetization. During milling of Mn-45, 70 and 85 at.% Al mixed powders, Al atoms are partially solubilized into an
phase. The Al supersaturated
phases change from paramagnetic to ferromagnetic : the saturation magnetization is 11 emu/g for the as-milled Mn-70 at.% Al powders. Moreover, by removing almost all Al atoms from the as-milled Mn-85 at.% Al powders using chemical leaching, the saturation magnetization increases up to 36 emu/g. The above bct
type alloys are the magnetic materials found for the first time, by using the present mechanochemical process.