Fe (002) Texture Formation Mechanism And Its Application In Magnetic Recording

The information era has two characters, including information explosion and transmission. Both of them are based on the data storage. As the major storage method, magnetic recording gains universal interest in society. At the same time, in order to satisfy people's insatiable demand of information storage, while maintaining its leading place in the data storage area, Hard Disk Drive industry and researchers in this area always aim to improve the recording density of HDD. As a result, its recording density continuously reaches a higher level from 5 Kbit/in² in 1956 to 250 Gbit/in² nowadays, and the size of single recording unit has been reduced to the scale of several nanometers. Under this condition, superparamagnetic effect becomes the fundamental factor limiting the improvement of recording density. We must use high Ku materials to surmount the effect. But this triggers another problem of writing limit. The information can hardly be written with current used magnetic head. Many methods are proposed to solve those problems, such as Heat-Assisted Magnetic Recording (HARM), Bit-Patterned Media (BPM), Exchange-Coupled Composite media (ECC) and so on. Among those methods, ECC media is believed to be the most applicable technique to be adopted by the next generation of magnetic recording system. But there is still not perfect design to realize this kind of media though many structures have been fabricated to demonstrate it. Many study work is needed to be done in this area. The work of his thesis aims to seek an applicable way to use FePt in the magnetic recording system, and then to fabricate recording media based on it.In this thesis, FePt/Fe bilayer has been proposed as the basic structure to form ECC media. FePt layer and Fe layer act as the hard and soft magnetic part respectively. Since ECC media could separate media's thermal stability and its switching field, in this structure we could use high Ku FePt to fabricate ultrahigh-density magnetic recording media. While the problem of writing limit can be resolved by the exchange coupling between FePt and Fe.In the first part of this thesis, Fe thin film with (002) texture was fabricated and the formation mechanism was discussed. In order to seek the acceptable fabricating condition, we systematically changed the sputtering parameters and the post-annealing condition. Finally, we give out the most proper condition. In second part of this thesis work, FePt (001) structure was grown on Fe (002) structure film by a texture-induced way. This is essential in fabricating perpendicular recording media based on L1₀ FePt. We also discussed epitaxial growth relationship between Fe and FePt layers and investigated the exchange coupling by changing the thickness of Fe layer. Eventually, we discussed the applicability of fabricating ECC media based on this double layer structure and its advantages.