• Title/Summary/Keyword: CR

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Effects of Mo and Si on the Coercivity of CoCrTa/CrMo and CoCrTa/CrSi Thin Film Media (CoCrTa/CrX (X=Mo, Si) 자성박막의 보자력에 미치는 Mo와 Si의 영향)

  • 조준식;남인탁;홍양기
    • Journal of the Korean Magnetics Society
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    • v.9 no.4
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    • pp.203-209
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    • 1999
  • Effects of Mo and Si addition in Cr underlayer on magnetic properties of CoCrTa/CrMo and CoCrTa/Si thin films media were investigated. Thin films were prepared with DC magnetron sputtering system. The thickness of CoCrTa magnetic layer and Cr underlayer were fixed at 300 $\AA$ and 700 $\AA$, respectively. The substrate heating temperature was kept constant at 26$0^{\circ}C$ for both magnetic layer and underlayer preparation. The coercivity increase of CoCrTa film was realized due to Mo addition in Cr underlayer. Si addition made a small decrease in coercivity. Coercivity increase seems to be attributed by the improvement of preferred orientation of Cr(200) plane. It is found that lattice fit between Cr(200) and CoCrTa(1120) of CrMo underlayer is better than that of CrSi underlayer. This small misfit may also contribute coercivity increase.

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Microstructures, mechanical properties, and tribological behaviors of Cr-Al-N, Cr-Si-N, and Cr-Al-Si-N coatings by a hybrid coating system (하이브리드 시스템을 이용한 Cr-Al-N, Cr-Si-N, Cr-Al-Si-N 코팅막의 미세구조와 기계적 특성과 마찰 거동에 관한 연구)

  • Yun, Chang-Seong;Kim, Gwang-Ho
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2007.11a
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    • pp.128-129
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    • 2007
  • Cr-Al-N, Cr-Si-N 그리고 Cr-Al-Si-N 코팅막을 WC-Co 모재위에 AIP법과 DC 마그네트론 스퍼터링 법을 결합한 하이브리드 시스템을 이용하여 합성하였으며, Si함량에 따른 Cr-Al-Si-N 코팅막의 미세구조, 기계적 특성과 마찰 거동에 관해 비교 연구하였다. Cr-Si-N(${\sim}35GPa$)과 Cr-Al-Si-N(${\sim}55GPa$) 코팅막의 경도값은 CrN(${\sim}23GPa$)과 Cr-Al-N(${\sim}25GPa$) 코팅막과 비교하여 각각 증가하였고, CrN(${\sim}0.50$)과 Cr-Al-N(${\sim}0.84$)의 평균 마찰계수는 Si 함량이 9 at.% 일때, Cr-Si-N(${\sim}0.30$)과 Cr-Al-Si-N(${\sim}0.57$)으로 각각 감소하였다.

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Effects of Cr Underlayer on Microstructural and Magnetic Properties of Sputtered CoNiCr/Cr, CoCrTa/Cr Films (Cr underlayer가 Sputter 증착한 CoNiCr/Cr, CoCrTa/Cr longitudinal 자기기록매채의 미세구조와 자성특성에 미치는 영향)

  • Park, S.C.;Ahn, B.T.;Im, H.B.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1992.11a
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    • pp.7-10
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    • 1992
  • CoNiCr/Cr and CoCrTa/Cr for longitudinal magnetic recording media were. prepared on Coming 7059 glass by RF magnetron sputtering. The thickness of Cr underlayer was varied from 500 to $3000{\AA}$ and. that of magnetic layer was $700{\AA}$. Coercivity and squareness were measured using V.S.M.(vibrating sample magnetometer). The coercivity of films increased with increasing Cr thickness when the films were unannealed. The coercivity of the films annealed in a 10 mtorr vacuum increased initially with annealing time and then saturated with further increase in annealing time. The coercivity value difference between the unannealed and annealed films increased with increasing the thickness of Cr underlayer No significant change was found in squareness after anneal, regardless of Cr underlayer thickness.

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The Effect of Additional Elements X on Magnetic Properties of CoCrTa/Cr-X Thin Film (CoCrTa/Cr-X 자성박막의 자기적성질에 미치는 첨가원소 X의 영향)

  • 김준학;박정용;남인탁;홍양기
    • Journal of the Korean Magnetics Society
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    • v.3 no.4
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    • pp.314-319
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    • 1993
  • The Effects of additional element X (X = Si, Mo, Cu, Gd) on magnetic properties and microstructure of Co-1Zat%Cr-Zat%Ta/Cr-X magnetic thin film were investigated. The thickness changes of Cr-X underlayer and CoCrTa magnetic layer were in the range of $1000~2000\AA$ and $200~800\AA$. respectively. Substrate temperatures were controlled from $100^{\circ}C$ to $200^{\circ}C$. Increase of coercivity by about 100~200 Oe was observed in CoCrTa/Cr-X thin films compared to those without additional X element. Cu was the most effective additional element for increasing coercivity. CoCrTa/Cr-Cu thin film shows relatively high coercivity in $1500\AA$ underlayer thickness and $600\AA$ magnetic layer thickness.

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A Study of Relationship between Magnetic Properties and Microstructure of CoNiCr/Cr Double Layer Thin Film Magnetic Recording Media (자기기록매체 CoNiCr/Cr 이중박막의 자기적 성질과 미세구조와의 관계연구)

  • 김희삼;남인탁;홍양기
    • Journal of the Korean Magnetics Society
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    • v.3 no.3
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    • pp.215-220
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    • 1993
  • Microstructural dependence of magnetic property of RF/DC sputtered $Co_{69.0}Ni_{18.5}Cr_{12.5}/Cr$ double layer thin film was studied. Grain size was found to be decreased with substrate temperature in the range of $100-200^{\circ}C$ and Cr underlayer thickness(from $500\;{\AA}-2000\;{\AA}$). The peaks (200) and (1120) of X-ray diffraction patterns were evidently grown with the substrate temperature for the Cr underlayer and magnetic layer, respectively. The CoNiCr magnetic layer was found to be well epitaxialy grown on Cr underlayer, and subsequently the coercivity was enhanced.

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The Effect of Sputtering Conditions on Magnetic Properties of CoCrMo/Cr Magnetic Thin Film (CoCrMo/Cr 자성박막의 제조조건이 자기적성질에 미치는 영향)

  • 박정용;남인탁;홍양기
    • Journal of the Korean Magnetics Society
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    • v.3 no.4
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    • pp.320-324
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    • 1993
  • The effect of sputtering conditions on magnetic properties of CoCrMo/Cr magnetic thin film was investigated. Substrate temperature were controlled from R. T to $250^{\circ}C$. The thickness changes of Cr underlayer and CoCrMo magnetic layer were in the range of $1000-2500\AA$ and $300-800\AA$, respectively. Grain size was found to be decreased with increasing magnetic layer thickness(from $500\AA$ to $800\AA$). CoCrMo magnetic layer microstructure showed relatively small dependence on Cr underlayer thickness, substrate temperature. Coercivity increased with increasing Cr underlayer, magnetic layer thickness and substrate temperature. CoCrMo/Cr thin film showed a coercivity of 880 Oe in $700\AA$ magnetic layer thickness and $1000\AA$ Cr underalyer thickness.

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Corrosion Behavior and Crystal Structure of Zn-Cr Coatings by EB-PVD and Electroplating (EB-PVD법과 전기화학방법으로 형성된 Zn-Cr film의 구조와 부식특성)

  • 최한철
    • Journal of the Korean institute of surface engineering
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    • v.36 no.6
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    • pp.423-429
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    • 2003
  • It has been investigated corrosion resistance and crystal structure of Zn-Cr coatings fabricated by electroplating method and electron-beam physical vapor deposition method(EB-P VD). The electroplated Zn-Cr alloy consists mainly of η'-Zn phase for the lower Cr content than 7.9 wt% Cr and ${\gamma}$'-ZnCr phase for the higher Cr content. In the Zn-Cr alloy fabricated by EB-PVD the ${\gamma}$'-ZnCr phase appeared clearly at 3 wt% Cr and it became the sole phase at 50 wt%Cr. The amount of η'-Zn phase decreased obviously with increasing Cr content when it exceeded 15 wt% Cr. The electrochemical measurement of the electroplated Zn-Cr film has shown corrosion potential of about -1000 mV. The current density of active region and the amount of dissolved Zn and Cr decreased significantly with increasing Cr content. The electrochemical characteristics of Zn-Cr alloy fabricated by EB-PVD have shown that the alloy of 50 wt% Cr had the highest corrosion potential(-500 mV) and the lowest critical passive current density than that of the electroplated.

Effects of CR Contents on Rubber Vulcanization and Mechanical Properties of NR/CR Blends (NR/CR 고무블랜드에서의 CR조성비가 가황 및 물성에 미치는 영향)

  • Ahn, Won-Sool;Park, Dong-Ryul
    • Elastomers and Composites
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    • v.46 no.2
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    • pp.152-157
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    • 2011
  • Effects of CR contents in NR/CR blends on the vulcanization kinetics and miscibility were studied by dynamic DSC and TGA, as well as the mechanical properties. While the vulcanization activation energy showed a constant value of $77.5{\pm}2.5$ kcal/mol regardless of CR contents, reaction rate, however, was observed to be somewhat lowered at increased CR contents. Partial miscibility was found between NR and CR phases at lower CR content of 3 wt%, but immiscibility was observed at higher CR content of 21 wt%. Mechanical properties were also affected by this miscibility, showing linear increase of compression set but decrease of tensile strength with CR contents in the blends.

Structural Characteristics by Nitridation of Oxygen Added Cr Thin Films in NH3 Atmosphere (산소가 첨가된 Cr 박막의 NH3 분위기에서의 질화 처리에 의한 구조적 특성)

  • Kim, Danbi;Kim, Seontai
    • Korean Journal of Materials Research
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    • v.31 no.11
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    • pp.635-641
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    • 2021
  • Cr thin films with O added are deposited on sapphire substrate by DC sputtering and are nitrided in NH3 atmosphere between 300 and 900 ℃ for various times. X-ray diffraction results show that nitridation begins at 500 ℃, forming CrN and Cr2N. Cr oxides of Cr2O3 are formed at 600 ℃. And, at temperatures higher than 900 ℃, the intermediate materials of Cr2N and Cr2O3 disappear and CrN is dominant. The atomic concentration ratios of Cr and O are 77% and 23%, respectively, over the entire thickness of as-deposited Cr thin film. In the sample nitrided at 600 ℃, a CrN layer in which O is substituted with N is formed from the surface to 90 nm, and the concentrations of Cr and N in the layer are 60% and 40%, respectively. For this reason, CrN and Cr2N are distributed in the CrN region, where O is substituted with N by nitridation, and Cr oxynitrides are formed in the region below this. The nitridation process is controlled by inter-diffusion of O and N and the parabolic growth law, with activation energy of 0.69 eV.