초음파 분산에 의한 수직자기기록용 Ba-ferrite의 자기적 특성 향상 |
최현승, 김창곤, 장학진, 정지형, 윤석영, 김태옥 |
부산대학교 무기재료공학과 |
Enhancement for Magnetic Property of Ba-ferrite for Perpendicular Magnetic Recording Using Ultrasonic Dispersion |
Hyun-Seung Choi, Chang-Gon Kim, Hak-Jin Jang, Ji-Hyung Jung, Seog-Young Yoon, Tae-Ok Kim |
Schools of Materials Science and Engineering, Pusan National University |
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ABSTRACT |
The various ultrasonic energies (28 kHz, 40 kHz, 70 kHz) were used to improve the magnetic properties of Ba-ferrite as the perpendicular magnetic recording materials. In the sheet formation process, the different orientation hars were used to orientate perpendicularly the dispersed Ba-ferrite to sheet. Throughout these experiments, we have obtained relatively higher value of S. Q. (Squreness Ratio : 0.783) and O. R. (Orientation Ratio : 2.87) magnetic properties at 2 h ultrasonic treatment of 40 kHz ultrasonic energy. With aid of SEM(Scanning Electron Microscopy) images, the obtained sheet with dispersed of Ba-ferrite could be used for perpendicular magnetic recording due to orientated to easy magnetization axis, c-axis. In addition, the value of S. Q. of sheet decreased with increasing applied magnetic field angle during measuring of S. Q. value with changing applied magnetic field angle by VSM (Vibrating Sample Magnetrometer). This result also induced the probability for prependicular magnetic recording. |
Key words:
Ultrasonic dispersion, Squareness ratio (S.Q.), Orientation ratio (O.R.), Orientation bar |
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