• Title/Summary/Keyword: Magnetic Annealing

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Physical Property Change of the Gapless Semiconductor $PbPdO_2$ Thin Film by Ex-situ Annealing

  • Choo, S.M.;Park, S.M.;Lee, K.J.;Jo, Y.H.;Park, G.S.;Jung, M.H.
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.371-372
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    • 2012
  • We have studied lead-based gapless semiconductors, $PbPdO_2$, which is very sensitive to external parameters such as temperature, pressure, electric field, etc[1]. We have fabricated pure $PbPdO_2$, Co- and Mn-doped $PbPdO_2$ thin films using the pulsed laser deposition. Because of the volatile element of Pb, it is very difficult to grow the films. Note that in case of $MgB_2$, Mg is also volatile element. So in order to enhance the quality of $MgB_2$, some experiments are carried out in annealing with Mg-rich atmosphere [2]. This annealing process with volatile element plays an important role in making smooth surface. Thus, we applied such process to our studies of $PbPdO_2$ thin films. As a result, we found the optimal condition of ex-situ annealing temperature ${\sim}650^{\circ}C$ and time ~12 hrs. The ex-situ annealing brought the extreme change of surface morphology of thin films. After ex-situ annealing with PbO-rich atmosphere, the grain size of thin film was almost 100 times enlarged for all the thin films and also the PbO impurity phase was smeared out. And from X-ray diffraction measurements, we determined highly crystallized phases after annealing. So, we measured electrical and magnetic properties. Because of reduced grain boundary, the resistivity of ex-situ annealed samples changed smaller than no ex-situ sample. And the carrier densities of thin films were decreased with ex-situ annealing time. In this case, oxygen vacancies were removed by ex-situ annealing. Furthermore, we will discuss the transport and magnetic properties in pure $PbPdO_2$, Co- and Mn-doped $PbPdO_2$ thin films in detail.

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The Study on Thermal Stability of NiCr Thin-films Resistor (NiCr 박막 저항계의 열적 안정성에 관한 연구)

  • Kim, I.S.;Jeong, S.J.;Kim, D.H.;Song, J.S.
    • Proceedings of the KIEE Conference
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    • 2001.11a
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    • pp.168-170
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    • 2001
  • The NiCr is an important material for present thin-film resistor application owing to its low TCR and thermal stability. In this work, the NiCr thin films were deposited on corning glass substrate by reactive magnetron sputtering and the annealing at temperatures range from 300 to $500^{\circ}C$ for 20 min in vacuum. X-ray, AFM, $R_s$(surface leakage current) have been used to study the structural and electrical properties of the NiCr thin films. The high precision NiCr thin films resistor with TCR(temperature coefficient of resistance) of less then 10 ppm/$^{\circ}C$ was obtained under in in-situ annealing at $300^{\circ}C$ on Cr buffer layer substrate. It is clear that the NiCr thin-films resistor electrical properties are low TCR related with it's annealing and buffer layer condition. NiCr thin film resistor having a good thermal stability and low TCR properties are expected for the application to the dielectric material of passive component.

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Core Losses of Amorphous Fe-B-Si Alloy for Transformer Core (변압기 철심용 Fe-B-Si비정질 합금의 철손 특성)

  • 김기욱;송재성;홍진완;강원구
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.40 no.1
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    • pp.67-72
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    • 1991
  • For improving the magnetic properties of the amorphous Fe-B-Si alloy, we annealed the sample in a magnetic field oriented in the plane of the ribbon longitudinal to its long axis. By field annealing, coercive force and total core loss are reduced from 0.04 Oe to 0.02 Oe, and from 0.25 watt/kg to 0.15 watt/kg respectively in comparsion with non-field annealed specimen. These reductions were caused by the formation of 180 dcmain wall parallel to the annealing field due to the induced anisotropy.

Magnetic Properties of Al-Co-N Thin Films Dispersed with Co Particles

  • Han, Chang-Suk
    • Journal of the Korean Society for Heat Treatment
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    • v.21 no.1
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    • pp.3-9
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    • 2008
  • Al-Co-N thin films, Al-Co-N/Al-N and Al-Co-N/Al-Co multilayers containing various amounts of Co content were deposited by using a two-facing targets type dc sputtering (TFTS) system. The films were also annealed successively and isothermally at different annealing temperatures. Irrespective of Co content and preparation methods, all the as-deposited films were observed non-magnetized. It was found that annealing conditions can control the magnetic and electrical properties as well as the microstructure of the films.

Influence of Layer-thickness and Annealing on Magnetic Properties of CoSiB/Pd Multilayer with Perpendicular Magnetic Anisotropy (박막 두께 및 열처리가 수직자기이방성을 갖는 CoSiB/Pd 다층박막의 자기적 특성에 미치는 영향)

  • Jung, Sol;Yim, Haein
    • Journal of the Korean Magnetics Society
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    • v.26 no.3
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    • pp.76-80
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    • 2016
  • CoSiB is the amorphous ferromagnetic material and multilayer consisting of CoSiB and Pd has perpendicular magnetic anisotropic property. PMA has strong advantages for STT-MRAM. Moreover, amorphous materials have two advantages more than crystalline materials: no grain boundary and good thermal stability. Therefore, we studied the magnetic properties of multilayers consisting of the $Co_{75}Si_{15}B_{10}$ with PMA. In this study, we investigated the magnetic property of the [CoSiB (3, 4, 5, and 6) ${\AA}$/Pd(11, 13, 15, 17, 19,and $24{\AA})]_5$ multilayers and found the annealing temperature dependence of the magnetic property. The annealing temperature range is from room temperature to $500^{\circ}C$. The coercivity and the saturation magnetization of the CoSiB/Pd multilayer system have a close association with the annealing temperature. Moreover, the coercivity especially shows a sudden increasing at the specific annealing temperature.

Microstructure and Magnetic Properties of $Nd_2Fe_{14}B/{\alpha}-Fe$ Nanocomposite Prepared by HDDR Combined with Mechanical Milling

  • Hu, Lianxi;Wang, Erde;Guo, Bin;Shi, Gang
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2006.09b
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    • pp.1286-1287
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    • 2006
  • [ $Nd_2Fe_{14}B/{\alpha}-Fe$ ] nanocomposite powders with a nominal composition of $Nd_{12}Fe_{82}B_6$ were prepared by HDDR combined with mechanical milling. The microstructure was studied by Mossbauer spectrometry and TEM. The magnetic properties were investigated by VSM using bonded magnet samples. The results showed that the annealing temperature had significant influence on both the recombination kinetics and the grain size of the $Nd_2Fe_{14}B$ and ${\alpha}-Fe$ phases, and the bonded magnets presented the best magnetic properties when the nanocomposite powders were prepared by annealing at $760^{\circ}C$ for 30 min.

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Tunable properties and low temperature sintering of BST thick films added ${Li_2}{CO_3}$ (${Li_2}{CO_3}$첨가에 의한 $BaSr(TiO_3)$의 저온 소결과 가변유전 특성)

  • Kim, In-Sung;Min, Bok-Ki;Jeong, Soon-Jong;Song, Jae-Sung;Jeon, So-Hyun
    • Proceedings of the KIEE Conference
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    • 2006.10a
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    • pp.7-9
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    • 2006
  • $(BaSr)TiO_3$ thick films were prepared by tape casting method using $BaTiO_3$ and $SrTiO_3$ powder slurry in order to investigate dielectric properties and low temperature sintering. Sintering density was $5.7\;g/cm^3$ and the BST sample exhibited the maximum dielectric constant, tunability at temperatures near phase transition point. The dielectric constant was increased and curie temperature was shifted to higher temperature with increasing of annealing temperature.

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The Effect of Curie Point Annealing on Electrophysical Phenomena at the Magnetized SrO 6$Fe_{2}O_{3}$ Ceramics/Electrolyte Interface (자화된 SrO 6$Fe_{2}O_{3}$ 세라믹스와 전해질 계면의 전기물리적 현상에 미치는 Curie점 열처리 효과)

  • 천장호;손광철;라극환
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.31A no.7
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    • pp.63-68
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    • 1994
  • The Curie point annealing effects on electrophysical phenomena at the magnetized strontium ferrite(SrO$\cdot$ 6$Fe_{2}O_{3}$) ceramics electrode/10$^{-3}$M KC1 aqueous electrolyte interfaces have been studied using cyclic voltammetric, normal pulse voltammetric, chronocoulometric, and electrochemical impedance techiques. After the Curie point annealing the magnetic flux densities of the speciment was decreased from 900-1100 gauss to 1-2 gauss, i.e. demagnetized. The real component of interfacial impedance was decreased from 7280-7320 ohm to 790-830 ohm. The adsorption and the charge on the electrical double layer was increased from 0 $\mu$C to -58 $\mu$C. The Curie point annealing and the related electrical double layer effect can influence not only the electrophysical properties of the strontium ferrite ceramics electrode itself but also the electrochemical phenomena at the electrode interface. This experimental results suggest that the Curie point annealing and the related electrical double layer effect can be applied to electrochemical magnetic sensors.

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