• 제목/요약/키워드: Co-Cr박막

검색결과 145건 처리시간 0.024초

기판온도에 따른 Co-22%Cr 합금박막의자가정렬형 나노구조 (Self-Organized Nano Structure in Co-22% Cr Alloy Thin Films with Substrate Temperatures)

  • 송오성;이영민
    • 한국표면공학회지
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    • 제34권6호
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    • pp.531-536
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    • 2001

  • Co-22 %Cr alloy films are promising for high-density perpendicular magnetic recording media with their perpendicular anisotropy and large coercivity of 3000 Oe. We observed that a self organized nano structure (SONS) of fine ferromagnetic Co-enriched phase and paramagnetic Cr-enriched phase appears inside the grain of Co-Cr magnetic alloy thin films at the elevated substrate temperature after do-sputtering. The periodic fine Co-enriched phase and Cr-enriched phase is the plate shape of 80 (equation omitted)-wide and 1000 (equation omitted)-long. Cr-enriched phases are located at the center of grains. We prepared 5000 (equation omitted) -thick Co-22 %Cr films on polyimide substrate with varying substrate temperature of $ 30^{\circ}C$, $ 150^{\circ}C$ ,200 $^{\circ}C$, $300^{\circ}C$, and $400^{\circ}C$, respectively. A transmission electron microscope equipped with energy dispersive X-ray analyzer is employed to observe the microstructure of each samples after Co-enri-ched phase are etched selectively. The self organized nano structure of Co-enriched and Cr-enriched lamellar is observed above the substrate temperture of $150^{\circ}C$. No compositional change is observed with substrate temperature. The compositional phase separation in self organized structure becomes clear as the substrate temperature increases. Our results implies that the self organized nano structure in Co-22 %Cr film is ideal for ultra high density recording media by recording selectively on Co-enri-ohed phase.

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$CoCr_{16.2}Pt_{10.8}Ta_4$ 합금박막의 Ti 우선증착에 따른 자기적 특성과 자구형상변화 (Magnetic properties and the shapes of magnetic domain for $CoCr_{16.2}Pt_{10.8}Ta_4$ alloy films with the prior deposition of Ti layer)

  • 이인선;김동원
    • 한국결정성장학회지
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    • 제10권1호
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    • pp.17-22
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    • 2000

  • 수직보자력이 크고 CoCrPt에 비하여 noise 저감 효과가 큰 것으로 알려진 CoCrPtTa계 합금박막의 수직이방성을 더욱 개선하기 위해 Ti를 우선 증착하였다. 본 연구에서는 Ti 두께 변화에 따른 비교적 높은 수직보자력치를 보였던 $CoCr_{16.2}Pt_{10.8}Ta_4$Ti/glass 시편에서 자기적 특성과 자구형상의 변화를 살펴보았다. 또한 VSM(Vibrating Sample Magnetometer)을 이용하여 M-H loop를 측정하였으며 자구형상은 MFM(Magnetic Force Microscopy)로 관찰하였다. 육방정 Ti가 하지층으로서 우선증착되면 bare glass 직접 증착되는 경우보다 CoCrPtTa 자성층의 수직이방성에 현저한 향상을 가져왔으며 Ti의 두께가 두꺼울수록 c-축 배향성도 개선되었다. MFM 결과에 의하면 Ti두레가 20 nm에서 90 nm로 증가함에 따라 자구형상이 연속적인 stripe type에서 mass type으로 분절된 형태로 변하였다. 이는 Ti의 증착이 비자성 Cr 편석 거동에 영향을 미쳐 자화반전시 인접 columnar grain의 자화벡터들간의 상호교환작용을 억제하는 자기적 분리 효과에 기여했음을 의미한다. 아울러 이와 같은 거동은 Ti가 CoCr계 자성층의 수직이방성을 개선하는데 있어서 형상자기이방성적인 측면에서의 기여가 현저함을 의미하기도 한다.

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Co-Cr-(Ta)박막의 자기특성 (The magnetic characteristics of Co-Cr-(Ta) films)

  • Kim, K-H;Jang, K-U;Kim, J-H;S Nakagawa;M Naoe
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1996년도 추계학술대회 논문집
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    • pp.242-244
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    • 1996

  • The effects of $Co_{67}$C $r_{33}$ underlayer on the crystallographec and magnetic characteristics of the Co-Cr-Ta layer deposited on the underlayer was investigated. The diffraction intensity $I_{p(002)}$ of Co-Cr-Ta layers on the $Co_{67}$C $r_{33}$ layer was stronger than that of single layer and Co-Cr-Ta/Ti double layer. Therefore, the crystallinity of Co-Cr-Ta layer was improved by the $Co_{67}$C $r_{33}$ underlayers rather than Ti ones. However, the coercivity $H_{c}$ of Co-Cr-Ta layers deposited on $Co_{67}$C $r_{33}$ underlayer was as low as 250 Oe even at substrate temperature of 22$0^{\circ}C$. This $H_{c}$ decrease seems to be attributed to the effect of the $Co_{67}$C $r_{33}$ underlayer as well as interval time between deposition of the underlayer and the Co-Cr-Ta layer.yer.layer.yer.

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수직자기기록매체 CoCrMo 박막의 구조와 자기적 성질 (Structural and Magnetic Properties of perpendicular Recording Medium CoCrMo thin Film)

  • 남인탁;홍양기
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1988년도 추계학술대회 논문집
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    • pp.46-46
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    • 1988

  • Structural and magnetic properties of Co-Cr-Mo films were investigated in connection with sputtering conditions. Films were prepared using a convention RF sputtering system. X-ray diffractometry, scanning electron microscopy and transmission electron microscopy were employed to investigate structure properties. Vibrating sample magnetometry was used for coercivity and saturation magnetization measurements. Co-Cr-Mo films displayed reasonable values of perpendicular coercivity and saturation magnetization for perpendicular recording media and showed good perpendicular orientation of the hcp c-axis to the film surface. Perpendicular coercivity was strongly dependent upon substrate technique showed better c-axis orientation than hose using the stationary substrate. Co-Cr-Mo films of 2.9 at. % Mo content showed maximum perpendicular coercivity and saturation magnetization. The films deposited at lower Ar pressure showed good magnetic properties. There was no explicit relationship between the columnar structure and c-axis orientation. Co-Cr-Mo films was found to have suitable structural and magnetic properties for perpendicular recording media.

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Co-Cr 자성합금 박막의 조성적 상분리 현상의 열역학적 고찰 (A Study on Thermodynamics for Compositional Separation in Co-Cr magnetic Alloy Films)

  • 송오성;전전안
    • 한국재료학회지
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    • 제9권4호
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    • pp.341-344
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    • 1999

  • We reported compositional separation(CS) into Co-enriched and Cri-enriched components inside the grains of Co-Cr based thin films prepared by rf sputtering. CS strongly depends on the sputtering conditions of substrate temperature and target composition. Tuning the microstructure of the Co-Cr films is important in order to employ the CS for high-density magnetic recording. We investigated the origin of CS from thermodynamic viewpoint. We employ a spinodal decomposition-like model to describe the origin of the CS in Co-Cr films. We consider the total free energy of the Co-Cr films as the sum of several free energies of; 1) thermodynamic mixing entropy of a binary solid solution, 2) magnetic ordering interaction(MOI) energy below the Curie temperature, and 3) excess interaction energy(XS) caused by the sputtering process as a function of temperature and composition. Those energies distorted the total free energy like the spinodal decomposition and caused the compositionally separated fine microstructure inside the grains. If the second derivative of the total free energy with respect to Cr composition becomes negative at a given substrate temperature, we may observe a metastable compositional separation inside the Co-Cr alloy films. We expect to exploit the microstructure of CS for ultra-high density magnetic recording.

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