• Journal of Magnetics
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• v.10 no.1
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• pp.28-32
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• 2005

The magnetic properties and ordering behavior of Nb-doped FePt alloy films prepared by dc-magnetron sputtering were investigated. It was found that Nb addition retarded the ordering reaction from the disordered face-centered-cubic (fcc) Al phase to the ordered face-centered-tetragonal (fct) L1₀ phase. The tetragonality (c/a ratio) of the ordered fct L1₀ phase increased with the Nb concentration. Nb addition hampered c-axis contraction during ordering, probably because the larger Nb atoms occupy Pt sites. Consequently, the coercivity and magnetocrystalline anisotropic energy of Nb-doped FePt alloy films are lower than those of un-doped FePt film under equivalent annealing conditions.

• Journal of Magnetics
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• v.9 no.1
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• pp.9-12
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• 2004

We have investigated sintering effects on Fe/Mo ordering and magnetoresistance (MR) in double perovskite-reflection lines due to $Sr_2FeMoO_6$ (SFMO). Polycrystalline samples have been prepared by the conventional solid-state reaction by sintering in a stream of 5% $H_2/Ar$ gas. All samples are single phase and exhibit a series of superstructurecation ordering at Fe and Mo sites. As sintering temperature increases from 900 to $1300^{\circ}C$, the degree of Fe/Mo ordering increases from 82 to 92%, magnetization (15 K, 7 kOe) increases from 1.6 to 2.7 ${\mu}_B/f.u.,$ and Curie temperature increases at a rate of 4.3 K/% with the increase of Fe/Mo ordering ratio. The magnitude of MR measured at 5 K is 19% for sample prepared at $1000^{\circ}C$ with magnetic fields of 7 kOe. The observed MR is proportional to the square of magnetization indicating that the MR feature in SFMO is explained by the spin-polarized tunneling at grain boundaries.

• Journal of Magnetics
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• v.15 no.2
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• pp.56-60
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• 2010

In this study, we investigated the optical, magnetic, and electrical transport properties of $Si_{1-x}Mn_x$ (0.1 < x < 0.9) single crystals grown by the vertical Bridgman method. The alloys with a Mn concentration of up to 64% demonstrated weak ferromagnetic ordering around $T_C=30\;K$. The $Si_{0.25}Mn_{0.75}$ and $Si_{0.18}Mn_{0.82}$ alloys showed weak ferromagnetic ordering at 70 K and antiferromagnetic ordering at 104 K, as confirmed by magnetization, neutron diffraction, and transport studies.

• Journal of the Korean Magnetics Society
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• v.18 no.5
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• pp.190-194
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• 2008

Epitaxial $L1_0$ FePd (001) thin films were successfully manufactured by sputtering deposition method. The structure and magnetic properties of FePd thin films were characterized as a function of Fe compositions. It was found that the long-range ordering parameter had a maximum for the stoichiometric composition, whereas the magnetic anisotropy had a maximum as the Fe content is decreased to slightly above the stoichiometric composition. This indicates that the stoichiometry is directly contributed to the chemical ordering and the magnetic anisotropy. These results imply that nonstoichiometric FePd compositions, with a slight excess of Pd, may in fact be preferred for applications that require high magnetic anisotropy.

• Proceedings of the KOSOMBE Conference
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• v.1990 no.11
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• pp.15-18
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• 1990

In abdominal NMR imaging the respiratory ordering techniques have been successfully used to remove the ghosting artifacts arising from the respiratory motion. In the existing respiratory ordering schemes, however, it is generally accepted that blurring of the moving parts still remains as in the signal averaging technique. A new optimal respiratory ordering scheme which can correct the blurring as well as the ghosting artifacts is theoretically derived through the analysis of the phase encoding directional motion effects in Fourier imaging. The performance of the optimal respiratory ordering scheme is experimentally confirmed together with a suboptimal ordering scheme which is suggested as a compromise for the practicality.

• Journal of Magnetics
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• v.16 no.2
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• pp.101-103
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• 2011

Solid solutions between $BaTiO_3$ and $LaFeO_3$ have been prepared through a solid state reaction method. The X-ray diffraction results reveal that $Ba_{1-x}La_xTi_{1-x}Fe_xO_3$ ($0.1\;{\leq}\;x\;{\leq}\;0.7$) compounds have a cubic structure, whereas the parent material $BaTiO_3$ has a tetragonal structure. The magnetization measurements indicate that the materials have a magnetic ordering at room temperature and the magnetic properties of the solid solutions depending on the doping amount of $LaFeO_3$. The origin of magnetic behaviors is believed to be from $Fe^{3+}$ ions.

• Journal of Powder Materials
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• v.13 no.2 s.55
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• pp.112-118
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• 2006

[ $R_{1/3}Sr_{2/3}FeO_{3}$ ](R=Pr, Nd, and Sm) was synthesized and their magnetic properties and charge ordering(CO) transition related with lattice dynamics and oxygen vacancy were systematically investigated. The charge disproportion ation(CD) in $R_{1/3}Sr_{2/3}FeO_{3}$(R=Pr,Nd) was in which two kins of iron with valence state $Fe^{3+}$ and $Fe^{5+}$ were found with ratio of 2:1. In this charge ordering state a sequence of $Fe^{3+}Fe^{3+}Fe^{5+}Fe^{3+}Fe^{3+}Fe^{5+}$ exists aligned along the [111] direction of the pseudocubic perovskite structure. The charge ordering exist in distorted structure involving $t_{pd}$ hybridization. The disordering phases coexist in distorted structure as temprature in creases that is controlled amount of oxygen vacancy. The magnetic hyperfine fields indicate charge tranfering temperature as it dissapeared drastically.

• Journal of the Korean Magnetic Resonance Society
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• v.2 no.1
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• pp.24-32
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• 1998

Drawn polyethylene was studied by 13C cross polarization magic angle spinning techniques. Solid-solid phase transition from orthorhombic to monoclinic crystalline phase by drawing was observed. In addition, using a synchronized magic angle spinning 2 dimension technique, we confirmed that macroscopic ordering of the polyethylene was produced by drawing.

• Progress in Superconductivity
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• v.6 no.1
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• pp.37-40
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• 2004

We investigated the effects of impurity doping on the electrical transport and magnetic properties of TEX>$(Ru, Sn)(Sr, La)<_2$$EuCeCu_2$$O_{z}$ samples. We found that Sn substitution fur Ru causes a significant decrease of the volume fraction of ferromagnetic phase, as well as a decrease of the temperature where the ferromagnetic component is observed. La substitution for Sr leads to an increase of the magnetic ordering temperature with a moderate change of ferromagnetic component. The experimental results are discussed in conjunction with the structural data, transport properties and a possible change of oxygen content.

• Journal of the Korean Magnetics Society
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• v.10 no.1
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• pp.7-10
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• 2000

The soft magnetic properties of Co-based amorphous alloy have been studied as a function of cooling condition after annealing. The F&W treatment (furnace cooling to 25$0^{\circ}C$ then water quenching) could increase 60~10$0^{\circ}C$ more the initial permeability than those of furnace cooled or water quenched alloys. These results are investigated in terms of thermal stress and ordering of magnetic ion pairs.