Abstract
Exchange coupled composite bit patterned media (ECC-BPM) are one candidate to solve the trilemma issues, overcome superparamagnetic limitations, and obtain ultrahigh areal density. In this work, the ECC continuous media and ECC-BPM of Fe/L10-FePt/Fe trilayer schemes are proposed and investigated based on the Landau-Lifshitz-Gilbert equation. The switching field,Hsw, of the hard phase in the proposed continuous ECC trilayer media structure is reduced below the maximum write head field at interlayer exchange coupling between hard and soft phases,Aex, higher than 20 pJ/m and its value is lower than that for continuousL10-FePt single layer media andL10-FePt/Fe bilayer. Furthermore, theHswof the proposed ECC-BPM is lower than the maximum write head field with exchange coupling coefficient between neighboring dots of 5 pJ/m andAexover 10 pJ/m. Therefore, the proposed ECC-BPM trilayer has the highest potential and is suitable for ultrahigh areal density magnetic recording technology at ultrahigh areal density. The results of this work may be gainful idea for nanopatterning in magnetic media nanotechnology.
Highlights
An ultrahigh areal density of magnetic recording media over 1 Tb/in2 and overcoming the superparamagnetic limit of conventional perpendicular magnetic recording are required for the development of hard disk drive technology
We have found that a hard phase of the proposed exchange coupled composite (ECC) media trilayer structure has a lower energy barrier than the bilayer structure with high thermal stability
For Aex over 15 pJ/m, the Hsw is almost constant according to the exchange energy. These results indicate that Aex is important for ECC media in reducing the Hsw below the maximum write head field at ultrahigh recording density
Summary
An ultrahigh areal density of magnetic recording media over 1 Tb/in and overcoming the superparamagnetic limit of conventional perpendicular magnetic recording are required for the development of hard disk drive technology. The high Ku is the cause of increasing coercivity, Hc, of the media; it may be over the maximum write field of about 24-25 kOe of heads because the saturation magnetization, Ms, of the write head material is limited [2]. These problems are called the magnetic recording trilemma [3]. There are three conditions of the trilemma that limits areal density growth of magnetic recording technology: (i) the write head field can record data on the media, (ii) the bits must be thermally stable, and (iii) the number of grains per bit is sufficient to obtain the high signal to noise ratio.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
