• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.100-103
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• 2001

In order to investigate the magnetic properties of CoCr-based bilayered thin films on kind of underlayer, we introduced amorphous Si layer to Co-Cr(-Ta) magnetic layer as underlayer. With the thickness of CoCr, CoCrTa single layer, crystalline orientation and perpendicular coercivity was improved. It was revealed that by introducing the Si underlayer, the c-axis orientation of CoCr, CoCrTa magnetic layer was improved largely. However, with increasing Si film thickness, perpendicular coercivity and saturation magnetization of Cocr/si, CoCrTa/Si bilayered thin films was decreased. Grain size of bilayered thin films became larger.

• 한국전기전자재료학회논문지
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• 제15권3호
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• pp.281-286
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• 2002

In odder to investigate the magnetic properties of CoCr-based bilayered thin films on kind of underlayer, we introduced amorphous Si layer to Co-Cr(-Ta) magnetic layer as underlayer. First, we prepared CoCr and CoCrTa single layer using the Facing Targets Sputtering system to investigate theirs properties. It was revealed that with increasing the film thickness of CoCr, CoCrTa single layer, crystalline orientation and perpendicular coercivity was improved. The CoCrTa thin film showed bettor crystalline and magnetic characteristics than CoCr thin film. As a result of investigating magnetic properties of CoCr and CoCrTa magnetic layer on introducing the Si underlayer, perpendicular coercivity and saturation magnetization of CoCr/Si and CoCrTa/Si bilayered thin film were decreased due to the increased grain size and diffusion of Si atoms to magnetic layer. And they showed constant with increasing the film thickness of Si thin film. However, in case of CoCrTa/Si bilayered thin film, in-plane coercivity was controlled low at about 250Oe. The c-axis orientations of CoCr/si and CoCrTa/Si bilayered thin film showed a good crystalline characteristics as about $2^{\circ}$.

• E2M - 전기 전자와 첨단 소재
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• 제11권10호
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• pp.72-77
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• 1998

The effects of Al micro-bumps on the magnetic properties of CoCr(Pt)Ta/Cr films deposited on glass substrates were investigated. The coercivity increased and the coercivity squareness decreased by incorporating Cr/Al underlayers. The cause of the coercivity increase is attributed to the reduction of Co(0002) texture, the increase of magnetic isolation of CoCr(Pt)/Ta grains, and the refinement of CoCr(Pt)/Ta grains deposited on Cr/Al underlayers. The effects of an Al overlayer on the magnetic properties of CoCr(Pt)Ta/Cr films were also studied. The decrease of coercivity squareness is ascribed to the magnetic isolation of CoCr(Pt)Ta grains.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 추계학술대회 논문집 Vol.15
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• pp.103-106
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• 2002

We prepared $Co_{77}Cr_{20}Ta_{3}$ thin film with Facing Targets Sputtering Apparatus. which can deposit a high quality thin film CoCrTa magnetic layer for Perpendicular magnetic recording media. In order to obtain Good Crystal orientation of CoCrTa thin films. We prepared Thin Films on slide glass substrate. The thickness of Buffer-layer were varied from 10 to 50 nm and Magnetic layer thickness fixed 100[nm]. input current was varied from 0.2[A] to 0.5[A]. Substrate temperature was varied from room temperature to ${250^{\circ}C}$ respectively. The crystal orientation of the CoCrTa film were examined with XRD. Introduce Buffer-layer thin films showed improvement of dispersion angle of c-axis orientation (${\Delta\theta}_{50}$).

• 한국자기학회:학술대회 개요집
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• 한국자기학회 1995년도 춘계연구발표회 논문개요집
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• pp.86-87
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• 1995

• 한국자기학회지
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• 제5권5호
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• pp.614-617
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• 1995

Thin CoCrTa/Cr films were deposited on glass substrates at $280^{\circ}C$ with or without Al underlayer. The coercivity of CoCrTa increased considerably by introducing an Al underlayer. The grain size of Cr thin film deposited on Al underlayer became smaller than that of Cr thin film deposited on glass substrate. The grain size of CoCrTa thin film was determined by Cr grain size. The cause of the coercivity increase seems to be associated with the refinement and uniform distribution of CoCrTa grains.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 하계학술대회 논문집
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• pp.208-211
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• 2000

We prepared Co-Cr-Ta and Co-Cr-Ta/Ti thin film for perpendicular magnetic recording media by facing targets sputtering system (FTS system). Ti underlayer effects on crystallographic and magnetic characteristics of Co-Cr-Ta perpendicular magnetic recording media have been investigated. Crystallgraphic and magnetic characteristic of prepared thin films were evaluated by x-ray diffractometry(XRD), vibrating sample magnetometer(VSM) and kerr hysteresis loop measurement. The coercivity and anisotropy field increase by introduced Ti underlayer when substrate temperature is higher than 150$^{\circ}C$. The c-axis dispersion angle and grain size of Co-Cr-Ta/Ti thin film is decrease than Co-Cr-Ta when substrate temperature is higher than 100$^{\circ}C$. Consequently, the use of a Ti underlayer highly orientated can be improved crystallographic and magnetic characteristics of Co-Cr -Ta perpendicular media layer.

• 한국자기학회지
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• 제3권1호
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• pp.41-47
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• 1993

Co-Cr계 수직자기기록매체에서 비교적 낮은 기판온도에서 높은 보자력을 얻기위하여 제 3원소로서 Ta의 첨가효과에 대하여 연구하였다. Cr함량이 17-21 at.%로 다른 Co-Cr 계에 Ta함량을 3.2 at.%까지 첨가시켜서 여러조성의 Co-Cr-Ta 박막을 제조하고, 자기적 성질 및 미세구조를 조사하였다. Ta첨가로 인한 수직보자력의 향상효과는 Cr함량이 낮은 박막의 경우에 컸으며, 특히 기판온도가 $100^{\circ}C$인 경우 그 향상효과가 더욱 뚜렷하였다. Ta의 첨가로 인한 수직보자력 향상은 결정립 미세화나, c-축 배향성향상에 의한 것이기 보다는 비강자성원소의 편석이 심화됨에 기인하는 것으로 판단된다.

• 한국자기학회지
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• 제3권4호
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• pp.314-319
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• 1993

Co-12at%Cr-2at%Ta/Cr-X 자성박막의 자기적성질과 미세구조에 미치는 첨가원소 X(X=Si, Mo, Cu, Gd)의 영향에 대해 조사하였다. Cr-X 하지층 및 CoCrTa 자성층의 두께는 각각 $1000~2000\AA$과 $200~800\AA$이었으며, 기판온도는 $100~200^{\circ}C$로 변화시켰다. Cr-X 하지층은 순수한 Cr 하지층에 비하여 보자력이 100 Oe~200 Oe 이상 증가하였다. Cu는 Gd, Mo, Si보다 높은 보자력 을 나타내는 Cr-X 하지층의 첨가원소 였으며 CoCrTa/Cr-Cu 자성박막은 하지층두께 $1500\AA$과 자성층두께 $600\AA$에서 높은 보자력을 나타내었다.

• 한국자기학회지
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• 제9권4호
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• pp.203-209
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• 1999

CoCrTa/Cr 자성박막의 Cr 하지층에 Mo와 Si을 첨가하여 제조한 박막의 자기적 성질에 미치는 Mo와 Si의 영향에 대하여 조사하였다. 증착시 사용된 장비는 DC magnetron sputtering system이었고, CoCrTa 자성층의 두께는 30.0$\AA$으로 Cr 하지층의 두께는 700$\AA$으로 고정하였으며 기판의 가열온도는 26$0^{\circ}C$이었다. CrMo 하지층의 박막이 순수한 Cr 하지층에 비하여 약 200 Oe의 보자력 증가를 나타내었다. 하지만 Si을 첨가하였을 경우엔 첨가량의 증가에 따라 보자력이 점차 감소하는 것으로 나타났다. CrMo 하지층에서는Mo를 첨가함에 따라 Cr 하지츠의 (200)면의 결정배향성이 증가하였고, Mo를 첨가한 Cr(200)과 CoCrTa(110)의lattice misfit가 Si을 첨가한 경우보다 작았고, 이것이 보자력 증가의 원인이었다.