접합유리와 반응된 Fe-Hf-N/Cr/SiO₂ 박막의 연자기 특성 열화

제해준,김병국,Je Hae-June,Kim Byung-Kook 한국재료학회 2004 한국재료학회지 Vol.14 No.11

The degradation mechanism of soft magnetic properties of $Fe-Hf-N/Cr/SiO_2$ thin films reacted with a bonding glass was investigated. When $Fe-Hf-N/Cr/SiO_2$ films were annealed under $600^{\circ}C$ without the bonding glass, the compositions and the soft magnetic properties of Fe-Hf-N layers were not changed. However, after reaction with the bonding glass at $550^{\circ}C$, the soft magnetic properties of the film were degraded. At $600^{\circ}C$, the saturation magnetization of the reacted film decreased to 13.5 kG, and its coercivity increased to 4 Oe, and its effective permeability decreased to 700. It was founded that O diffused from the glass into the Fe-Hf-N layers during the reaction and generated $HfO_2$ phases. It was considered that the soft magnetic properties of the $Fe-Hf-N/Cr/SiO_2$ films reacted with the bonding glass were primarily degraded by the formation of the Fe-Hf-O-N layer of which the Fe content was below 60 $at\%$, and secondarily degraded by the Fe-Hf-O-N layer above 70 $at\%$.

V₂O₅ 도핑된 NiCuZn 페라이트로 제조된 칩인덕터에서의 Ag/cu 석출

제해준,김병국,Je, Hae-June,Kim, Byung-Kook 한국재료학회 2003 한국재료학회지 Vol.13 No.8

The purpose of this study is to investigate the effect of $V_2$$O_{5}$ addition on the Ag and Cu precipitation in the NiCuZn ferrite layers of 7.7${\times}$4.5${\times}$1.0 mm sized multi-layer chip inductors prepared by the screen printing method using 0∼0.5 wt% $V_2$$O_{5}$ -doped ferrite pastes. With increasing the $V_2$$O_{5}$ content and sintering temperature, Ag and Cu oxide coprecipitated more and more at the polished surface of ferrite layers during re-annealing at $840^{\circ}C$. It was thought that during the sintering process, V dissolved in the NiCuZn ferrite lattice and the Ag-Cu liquid phase of low melting point was formed in the ferrite layers due to the Cu segregation from the ferrite lattice and Ag diffusion from the internal electrode. During re-annealing at $840^{\circ}C$, the Ag-Cu liquid phase came out the polished surface of ferrite layers, and was decomposed into the isolated Ag particles and the Cu oxide phase during the cooling process.

Mn - Zn 페라이트 단결정과 접합유리와의 계면반응이 자기적특성에 미치는 영향

제해준(Hae June Je),김영환(Young Hwan Kim),김병국(Byung Kook Kim),박재관(Jae Gwan Park) 한국자기학회 2001 韓國磁氣學會誌 Vol.11 No.5

The effect of interface reaction between Mn-Zn ferrite single crystal and 61SiO₂-23PbO-6ZnO-8Na₂0-2K₂0 (㏖%) glass on the magnetic properties of the ferrite was investigated. After the reaction, the hump of Zn concentration appeared at the ferrite adjacent to the interface. The initial permeability of the ferrite bonded with the glass at 700℃ was 1766 at 100 KHz and reduced to 907 after reaction at 1000 ℃. The permeability degradation with increasing reaction temperature was considered to be attributed not only to the size diminution of the ferrite due to the its dissolution into the glass but also to the residual stress due to the difference in expansion coefficient between the ferrite and the diffusion layer-the region of the hump of Zn concentration-adjacent to the interface.

V₂O5 도핑한 페라이트 페이스트로 제조된 칩인덕터의 자기적 특성

제해준(Hae June Je) 한국자기학회 2003 韓國磁氣學會誌 Vol.13 No.3

The purpose of this study is to investigate the effect of V₂O_5 addition on the microstructures and magnetic properties of 7.7×4.5×1.0 ㎜ sized multi-layer chip inductors prepared by the screen printing method using 0~0.5 wt% V₂O_5-doped NiCuZn ferrite pastes. With increasing the V₂O_5 content, the exaggerated grain growth of ferrite layers was developed due to the promotion of Ag diffusion and Cu segregation into the grain boundaries of ferrites, which affected significantly the magnetic properties of the chip inductors. After sintering at 900oC, the inductance at 10 MHz of the 0.5 wt% V₂O_5-doped chip inductor was 3.7 ?H less than 4.2 ?H of the 0.3 wt% V₂O_5-doped one, which was thought to be caused by the residual stress at the ferrite layers increased with the promotion of Ag diffusion and Cu segregation. The quality factor of the 0.5 wt% V₂O_5-doped chip inductor decreased with increasing the sintering temperature, which was considered to be caused by the electrical resistivity of the ferrite layer decreased with the promotion of Ag/Cu segregation at the grain boundaries and the growth of the mean grain size of ferrite due to exaggerated grain growth of ferrite layers.

분산제가 BaTiO₃/에폭시 복합체의 유전특성에 미치는 영향

이동호,김병국,제해준,Lee, Dong-Ho,Kim, Byung-Kook,Je, Hae-June 한국재료학회 2009 한국재료학회지 Vol.19 No.11

$BaTiO_3$/epoxy composites have been widely investigated as promising materials for embedded capacitors in printed circuit boards. It is generally known that the dielectric constant (K) of the $BaTiO_3$/epoxy composites increases with improvement of the dispersion of $BaTiO_3$ particles in the epoxy matrix that comes from adding surfactant. The influences of surfactant addition on the dielectric properties of the $BaTiO_3$/epoxy composites are reported in the present study. The dielectric constant of the $BaTiO_3$/epoxy composites is not significantly affected by the surfactant addition. However, the temperature coefficient of capacitance increases and the peel strength decreases as the amount of added surfactant increases. The influences of surfactant addition on the dielectric properties of the neat epoxy are also very similar to those of the $BaTiO_3$/epoxy composites. The residual surfactant in the $BaTiO_3$/epoxy composites affects the temperature coefficient of capacitance and the peel strength of the epoxy matrix, which in turn affects the temperature coefficient of capacitance and the peel strength of the $BaTiO_3$/epoxy composites.

X-선 회절분석법에 의한 $Ba(Zn_{1/3}Ta_{2/3})O_3$의 격자 비틀림 측정

김정돈,김인태,제해준,Kim, Chong-Don,Kim, In-Tae,Je, Hae-June 한국분석과학회 1992 분석과학 Vol.5 No.1

$Ba(Zn_{1/3}Ta_{2/3})O_3$는 고온에서 열처리시 Zn과 Ta 이온이 ordering을 일으키며 이때 격자 비틀림이 일어난다. 본 실험에서는 이러한 격자비틀림을 X-선 분말회절법을 사용하여 1/10,000 이상의 정밀도로 측정하였으며, 그 결과 $Ba(Zn_{1/3}Ta_{2/3})O_3$는 $1350^{\circ}C$ 30분 소결시에도 상당한 정도의 격자 비틀림이 발생하며 이러한 격자비틀림은 소결시간이 길어질수록 증가함을 관찰하였다. Ordering phenomena were observed for Zn and Ta cations of $Ba(Zn_{1/3}Ta_{2/3})O_3$ under particular heat treatments, followed by a considerable lattice distortion. This lattice distortion was measured by X-ray powder diffraction with a precision of higher than 1/10,000. From this investigation, a significant lattice distortion occurred within 30 min. of sintering at $1350^{\circ}C$, and it was increased with sintering time.

임베디드 커패시터용 세라믹(BaTiO₃)-고분자(에폭시) 필름의 세라믹 분말 형상 및 함량에 따른 전기적 특성

한정우,윤중락,제해준,이동호,이경민,Han, Jeong-Woo,Yoon, Jung-Rag,Je, Hae-June,Lee, Dong-Ho,Lee, Kyung-Min 한국전기전자재료학회 2009 전기전자재료학회논문지 Vol.22 No.6

The ceramic($BaTiO_3$)-polymer(epoxy) composites have been widely investigated as dielectric materials for embedded capacitors in printed circuit boards (PCBs). The dielectric properties of $BaTiO_3$/epoxy composites prepared using the agglomerated $BaTiO_3$ particles were investigated in the present study. The dielectric constants of the composites prepared using the agglomerated $BaTiO_3$ particles were about 2 times higher than those of the composites with the dispersed $BaTiO_3$ particles. The insulation resistance of the composites prepared using the agglomerated $BaTiO_3$ particles were lower than those of the composites with dispersed $BaTiO_3$ particles. As a result, there is tradeoff between high dielectric constant and insulation resistance in the $BaTiO_3$/epoxy composites. So it is important to select proper agglomerated or dispersed $BaTiO_3$ particles in accordance with needs.

분말 응집도가 BaTiO₃/에폭시 복합체의 유전특성에 미치는 영향

한정우,김병국,제해준,Han, Jeong-Woo,Kim, Byung-Kook,Je, Hae-June 한국재료학회 2008 한국재료학회지 Vol.18 No.10

$BaTiO_3$/epoxy composites can be applied as the dielectric materials for embedded capacitors. The effects of the degree of $BaTiO_3$ particle agglomeration on the dielectric properties of $BaTiO_3$/epoxy composites were investigated in the present study. The degree of particle agglomeration was controlled by the milling of the agglomerated particles. The size and content of the agglomerated $BaTiO_3$ particles decreased with an increase in the milling time. The dielectric constants and polarizations of $BaTiO_3$/epoxy composites abruptly decreased with the increase of the milling time. It was concluded that the dielectric constants and polarizations of $BaTiO_3$/epoxy composites decreased as the degree of particle agglomeration decreased. The degree of agglomeration of $BaTiO_3$ particles turned out to be a very influential factor on the dielectric properties of $BaTiO_3$/epoxy composites.

산화철 폐촉매로부터 합성된 NiZn- 페라이트의 자기적 특성

황연,권순길,이효숙,제해준,박상일,Hwang, Yeon,Kwon, Soon-Kil,Lee, Hyo-Sook,Je, Hae-June,Park, Sang-Il 한국세라믹학회 2001 한국세라믹학회지 Vol.38 No.12

석유화학 공정 중 Styrene(SM) 공정에서 발생되는 산화철 폐촉매는 산업 폐기물로서 전량 매립되고 있는데, 이를 출발 원료로 사용하여 NiZn-페라이트를 합성하였고 그 자기적 특성을 조사하였다. 산화철 폐축매 펠렛을 분쇄한 후 NiO 및 ZnO를 혼합하여 90$0^{\circ}C$에서 하소하고 123$0^{\circ}C$에서 5시간 소결하여 스핀넬형 페라이트 소결체를 얻었다. N $i_{x}$ Z $n_{1-x}$F $e_2$ $O_4$(x=0.36, 0.50, 0.66)조성에 대하여 초투자율을 측정하였고, S-parameter를 측정하여 반사 감쇄량을 계산하였다. 산화철 폐촉매를 이용하여 X-band 주파수 영역에서 높은 전자파 흡수능을 갖는 전파흡수체를 제조할 수 있음을 확인하였다.다. NiZn-ferrite was synthesized from waste catalysts, which were produced from styrene monomer process and buried underground as an industrial wastes, and its magnetic properties were investigated. Nickel oxide and zinc oxide powders were mixed with finely ground waste catalysts, and spinel type ferrite was obtained by calcination at 900$\^{C}$ and sintering at 1230$\^{C}$ for 5 hours. The intial permeability was measured and reflection loss was calculated from S-parameters for the composition of Ni$\_$x/Zn$\_$1-x/Fe$_2$O$_4$(x=0.36, 0.50, 0.66). NiZn-ferrite synthesized from waste iron oxide catalyst showed a feasibility for the use as electromagnetic wave absorber in X-band.

초미립 $\textrm{La}^{3+}$-doped $\textrm{BaTiO}_3$세라믹스의 미세구조 및 유전특성

조지만,김병호,김긍호,제해준,이해원,김병국,Cho, Ji-Man,Kim, Byong-Ho,Kim, Gyeung-Ho,Je, Hae-June,Lee, Hae-Won,Kim, Byung-Kook 한국재료학회 1999 한국재료학회지 Vol.9 No.10

초미립 $BaTiO_3$분말을 출발물질로 하고 $\textrm{La}_{3+}$을 0~2 mol% 첨가하여 $1200~1400^{\circ}C$에서 소결하였을 때 $\textrm{La}_{3+}$을 첨가하지 않고 $1350^{\circ}C$ 이상에서 소결한 경우를 제외하고는 모두 110~240 nm의 평균입경을 갖는 초미립의 $\textrm{La}_{3+}$-doped $BaTiO_3$소결체를 얻을 수 있었다. 이 때, 평균입경이 240 nm에서 110 nm로 감소함에 따라 정방정비 (c/a), $90^{\circ}$ 분역의 부피분율, 상온 비유전율, 상전이온도($\textrm{T}_{c}$)에서의 최대 비유전율, $\textrm{T}_{c}$ 에서의 상전이 완만화도 등은 모두 감소하였다. 이와 같은 유전특성의 입경 의존성은 평균입경 감소에 따른 $90^{\circ}$ 분역 생성의 억제 및 그에 따른 내부응력의 영향으로 해석하였다. When the 0-2 mol% of $\textrm{La}_{3+}$ were added to the nanocrystalline $BaTiO_3$ powders and sintered at $1200~1400^{\circ}C$, the nanocrystailine $BaTiO_3$ ceramics having the average grain size of 110-240 nm were obtained except for when no $\textrm{La}_{3+}$ was added and sintered at > $1350^{\circ}C$. As the average grain size decreased from 240 nm to 110 nm, the tetragonality (c/a) and volume fraction of the $90^{\circ}$ domain decreased, and all the properties such as relative dielectric constant at room temperature, maximum relative dielectric constant at the temperature of phase transformation $\textrm{T}_{c}$ and diffuseness of phase transformation at $\textrm{T}_{c}$ also decreased. The results were attributed to the internal stress induced by inhibition of the $90^{\circ}$ domain formation in the case of finer grain size.