The Study of Cr Underlayer Effect on the Sm-Co Based Thin Films for Longitudinal Recording Media

• Main Authors: Kuei Yann Wu, 吳桂燕
• Other Authors: Chen Shi Kun
• Format: Others
• Language: en_US
• Published: 1999
• Online Access: http://ndltd.ncl.edu.tw/handle/mn9r84

碩士 === 逢甲大學 === 材料科學學系 === 87 === IBM and Hitachi announced that in the near future magnetic recording products with 10 Giga-bits/in2 will be available. The coercivity (Hc) required for a recording density of 10 Giga-bits/in2 in a longitudinal medium may range from 2.5 kOe to 4.5 kOe. Sm-Co film with high magnetocrystalline anisotropy constant ( K1 = 7.7×107 erg/cm3 ) is a potential candidate for the future high density recording medium. Therefore, we study a set of Sm-Co films prepared by dc-magnetron sputtering system, the aim is intent to fabricate the high density and low noise longitudinal Sm-Co / Cr recording medium, and to study the effects of Cr underlayer and thickness. This experiments can be devided into three major parts: (a) texture and room temperature magnetic property were examined by XRD and VSM, (b) macro-structure and micro-structure analyse were done by AFM, SEM, TEM, and MFM, and (c) exchange coupling (ΔM ) was measured by VSM. At last, we try to find out the relationship between magnetic property - structure - exchange coupling, to obtain Sm-Co / Cr double - layer structure for high coercivity and low noise recording media. The result of this experiment, under optimum conditions we achieve intrinsic coercivity 1 ~ 6.06 kOe and ΔM 0.08 ~ 0.25 for Sm-Co films with thickness < 100 nm and Cr underlayers with thickness ~ 110 nm.