• 제목/요약/키워드: Dipolar

검색결과 183건 처리시간 0.025초

전기도금법으로 제작한 CoPt 자성막의 자기상호작용과 자기적 성질 (Magnetic Interaction and Magnetic Properties of Electrodeposited CoPt Magnetic Films with Different Thickness)

  • 김현수;이종덕;정순영;이창형;서수정
    • 한국자기학회지
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    • 제21권5호
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    • pp.151-156
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    • 2011
  • 전기도금법으로 제작한 CoPt 자성막의 두께가 자기상호작용과 자기적 성질에 미치는 영향을 잔류자기화 곡선과 자기이력 곡선을 측정 분석하여 규명하였다. CoPt 자성막의 두께가 증가함에 따라 수직 보자력과 포화자화가 증가하였으나 각형비는 급격히 감소하였다. 잔류자화 곡선의 분석결과로부터 모든 시료의 주된 자기상호작용 기구는 쌍극자 상호작용이며, 시료의 두께가 증가함에 따라 상호작용의 세기가 증가함을 알 수 있었다.

Calculation of the NMR Cheimical Shift for a 4d$^1$ System in a Strong Crystal Field Environment of Trigonal Symmetry with a Threefold Axis of Quantization

  • Ahn, Sang-Woon;Oh, Se-Woung;Ro, Seung-Woo
    • Bulletin of the Korean Chemical Society
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    • 제7권3호
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    • pp.170-178
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    • 1986
  • The NMR chemical shift arising from 4d electron angular momentum and 4d electron angular momentum and 4d electron spin dipolar-nuclear spin angular momentum interactions for a $4d^1$ system in a strong crystal field environment of trigonal symmetry, when the threefold axis is chosen to be the axis of quantization axis, has been examined. A general expression using the nonmultipole expansion method (exact method) is derived for the NMR chemical shift. From this expression all the multipolar terms are determined. We observe that along the (100), (010), (110), and (111) axes the NMR chemical shifts are positive while along the (001) axis, it is negative. We observe that the dipolar term (1/R3) is the dominant contribution to the NMR chemical shift except for along the (111) axis. A comparison of the multipolar terms with the exact values shows also that the multipolar results are exactly in agreement with the exact values around $R{\geqslant}0.2$ nm. The temperature dependence analysis on the NMR chemical shifts may imply that along the (111) axis the contribution to the NMR chemical shift is dominantly pseudo contact interaction. Separation of the contributions of the Fermi and the pseudo contact interactions would correctly imply that the dipolar interaction is the dominant contribution to the NMR chemical shifts along the (100), (010), (001), and (110) axes, but along the (111) axis the Fermi contact interaction is incorrectly the dominant contribution to the NMR chemical shift.

UV/Ozone 조사에 의한 Poly(phenylene sulfide) 필름의 표면처리와 염색성 (Surface Treatment and Dyeability of Poly(phenylene sulfide) Films by UV/O3 Irradiation)

  • 장용준;장진호
    • 한국염색가공학회지
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    • 제23권4호
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    • pp.284-289
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    • 2011
  • Poly(phenylene sulfide)(PPS) films were photooxidized under UV/ozone irradiation. The effect of UV energy on the surface properties of the UV-irradiation PPS films were investigated by the measurement of reflectance, surface roughness, and contact angle. Reflectance decreased at the wavelength of 400nm and the surface roughness increased with increased UV energy. The improvement in hydrophilicity with increased $O_{1s}/C_{1s}$ was caused by the introduction of hydrophilic $SO_2$ bond. Surface energy increased from 46.6 to $78.3mJ/m^2$ with increased UV energy up to $21.2J/cm^2$. Also zeta potential decreased with increased UV energy. The increased dyeability to cationic dyes may be due to the photochemically introduced anionic and dipolar dyeing sites on the PPS films surfaces.he photochemically introduced anionic and dipolar dyeing sites on the PPS films surfaces.

Polarizing Group Attached Acrylates and Polymers Viewing High Refractive Index

  • Kwon, Ji-Yun;Kim, Bong-Gun;Do, Jung-Yun;Ju, Jung-Jin;Park, Seung-Koo
    • Macromolecular Research
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    • 제15권6호
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    • pp.533-540
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    • 2007
  • We designed and successfully synthesized UV curable, functional acrylate monomers having a polarizing group, i.e., an electron-withdrawing and/or electron-donating group for the optical materials of high refractive index. Optical polymer films made from the functional methacrylate monomers were achieved with photo crosslinking under UV illumination. A monomer having amino and cyano groups (Dimer-CN) exhibited the highest refractive index ($n_{TE}$=1.595 at 850nm) among the studied methacrylate derivatives, due to the large polarizability of the dipolar monomer structures with electron-donating and withdrawing groups. By controlling the compositions of the functional acrylate monomer of copolymers, the refractive indices of the polymers were readily adjusted within a wide range of 1.498-1.595. The copolymers showed a high glass transition temperature $(T_g)$ and good thermal stability, which are desirable for optical applications. $T_g$ and $T_{10%}$ (10%-weight loss occurred) of the copolymers ranged from $120-140^{\circ}C$ and from $329-387^{\circ}C$, respectively.