• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.492-495
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• 2000

In order to develop an ultra-thin CoCr perpendicular magnetic recording layer, we prepared CoCrTa/Ti double layer for perpendicular magnetic recording media by new facing targets sputtering system, Crystallgraphics and magnetic characteristics of CoCrTa on underlayer substrate temperature have been investigated. Crystallgraphic and magnetic characteristic of thin films were evaluated by X-ray diffractometry(XRD), vibrating sample magnetometer(VSM) and atomic force microscopy(AFM). The coercivity and anisotropy field was increased by increasing under layer substrate temperature, c-axis orientation of CoCrTa magnetic recording layer was improved 8$^{\circ}$ to 5.6$^{\circ}$when under layer substrate temperature was 250[$^{\circ}C$]. Also, through annealing effect for CoCrTa/Ti double layer, it was certain that crystallgraphics and magnetic characteristics was improved.

• Proceedings of the Korean Magnestics Society Conference
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• 2003.06a
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• pp.228-229
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• 2003

• Proceedings of the Korean Magnestics Society Conference
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• 2005.06a
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• pp.126-127
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• 2005

• Journal of the Korean Magnetics Society
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• v.1 no.2
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• pp.74-78
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• 1991

The method for analyzing the recording and reading process of magnetic recording system by numerical simulation is introduced. which can simulate the effect of elements of the magnetic recording system. During the whole simulation, hysteresis characteristics must be included. Preisach model and finite element method are used to construct the algorithm. From the wave of recording current, recorded pattern of magnetization in recording media is simulated in recording process, and then waveform of reading signal in head coil is obtained in reading process. To show the validity of this method, this is applied to perpendicular magnetic recording system. Waveform of recording signal and reproduced signal is obtained in several density. Pattern of reprocuced voltage magnitude according to increase of recording density shows roll-off curve.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.5
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• pp.418-422
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• 1998

The Co-Cr films are one of the most suitable candidates for perpendicular magnetic recording media. The facing targets sputtering(FTS) system has a advantage of preparing films over a wide range of working gas pressure on plasma-free substrate. In this study, we investigated the possibility of employing FTS system for depositing Co-Cr films. The Co-Cr thin films were deposited with various sputter gas pressure($P_Ar$, 0.1~10mTorr) by using FTS apparatus at temperature of $40^{\circ}C and 220^{\circ}C$, respectively. Crystallographic and magnetic characteristics were evaluated by x-ray diffractometry (XRD) and vibrating sample magnetometer(VSM), respectively. Under argon gas pressure at 0.1mTorr, films with morphologically dense microstructure, good c-axis orientation and higher coercivity were obtained. It has been confirmed that the FTS system is very useful for preparing Co-Cr thin film recording media.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.77-80
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• 2001

Crystallographic and magnetic characteristics of CoCr-based magnetic thin film for perpendicular magnetic recording media were influenced on preparing conditions. In these, there is that substrate temperature was parameter that increases perpendicular coercivity of CoCrTa magnetic layer using recording layer. While preparation of CoCr-based doublelayer, by optimizing substrate temperature, we expect to increase perpendicular anisotropy of CoCr magnetic layer and prepare ferromagnetic recording layer with a good quality by epitaxial growth. CoCrTa/Si doublelayer showed a good dispersion angle of c-axis orientation $\Delta\theta_{50}$ caused by inserting amorphous Si underlayer which prepared at underlayer substrate temperature 250C. Perpendicular coercivity was constant, in-plane coercivity was controlled a low value about 200Oe. This result implied that Si underlayer could restrain growth of initial layer of CoCrTa thin film, which showed bad magnetic properties effectively without participating magnetization patterns of magnetic layer. In case of CoCrTa/Si that prepared with ultra thin underlayer, crystalline orientation of CoCrTa was improved rather underlayer thickness 1nm, it was expected that amorphous Si layer played a important role in not only underlayer but also seed layer.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07a
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• pp.550-552
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• 2003

We prepared $Co_{77}Cr_{20}Ta_3$ Magnetic layer for perpendicular magnetic recording media with introduce Two-step methode and Amorphous Si Underlayer on slide glass substrate. The thickness of magnetic layer were 100nm, and Underlayer were varied from 5 to 100 nm. The multi layer Properties of crystal structure were examined with XRD. Prepared thin films showed improvement of dispersion angle of c-axis orientation ${\Delta}{\theta}_{50}$ caused by inserting Buffer-layer and amorphous Si underlayer.

• Journal of Magnetics
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• v.18 no.2
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• pp.86-89
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• 2013

This paper shows a new effective approach to measure crystallization temperature of soft magnetic underlayer (SUL) for next generation of heat assisted perpendicular recording media. This approach uses temperature dependent reflectivity, which shows a clear jump when samples are crystallized. To achieve this measurement, an optical system is set up using hot plate and infrared laser. Reflectivity of SUL $(Co_{70}Fe_{30})_{92}Ta_3Zr_5$ shows a clear jump at its amorphous-crystalline transition temperature. Experiment results show this effect is clear in infrared region, and is weak for visible light.

• Proceedings of the Korean Magnestics Society Conference
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• 2002.12a
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• pp.178-179
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• 2002

CoCrPt alloy films are one of the most promising candidates for high-density perpendicular magnetic recording media due to their strong perpendicular magnetic anisotropy (PMA) and high coercivity [1]. In order to achieve high-density magnetic recording media, it is essential to characterize the magnetoelastic properties since experimental and theoretical research has revealed a significant magnetoelastic contribution to the magnetic properties in magnetic thin films. (omitted)

• Proceedings of the Korean Magnestics Society Conference
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• 1998.05a
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• pp.26-27
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• 1998