Effects of Magnetic Properties of L10-CoPt based Bit Patterned Media with Tilted-Easy Axis on Switching Field at Areal Density over 2 Tb/in2

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.781.207 ◽

2015 ◽

Vol 781 ◽

pp. 207-210

Author(s):

Arkom Kaewrawang

Keyword(s):

Magnetic Properties ◽

Easy Axis ◽

Magnetocrystalline Anisotropy ◽

Areal Density ◽

Anisotropy Constant ◽

Magnetic Media ◽

Switching Field ◽

Bit Patterned Media ◽

Patterned Media ◽

Easy Direction

Decrease of a switching field, Hsw, of the magnetic media with high magnetocrystalline anisotropy constant, Ku, can be handled by tilted-easy axis. Not only tilting easy direction of crystal but also optimum magnetic properties can improve writability. The effects of Ku and saturation magnetization, Ms, of L10-CoPt material of BPM with 45° tilted-easy axis are investigated in this article. The object oriented micromagnetic framework package based on Landau - Lifshitz - Gilbert equation has been used to analyze the magnetic properties of media in this paper. The results indicate that the Hsw decreases with decreasing Ku and increasing Ms. To achieve the Hsw lower than the maximum write head field, the Ku and Ms values should not be over 1.30 MJ/m3 and should exceed 0.30 MA/m, respectively.

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The Effects of Magnetic Properties of L10-FePt/Fe Based Exchange Coupled Composite Media on Switching Field

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.931-932.271 ◽

2014 ◽

Vol 931-932 ◽

pp. 271-275 ◽

Cited By ~ 1

Author(s):

Warunee Tipcharoen ◽

Arkom Kaewrawang ◽

Apirat Siritaratiwat ◽

Kittipong Tonmitra

Keyword(s):

Magnetic Properties ◽

Magnetic Recording ◽

Exchange Coupling ◽

Magnetocrystalline Anisotropy ◽

Areal Density ◽

Anisotropy Constant ◽

Recording System ◽

Switching Field ◽

Magnetic Parameters ◽

Exchange Coupled Composite

The L10-FePt/Fe based exchange coupled composite (ECC) bilayer media is one candidate to extend the areal density of magnetic recording system and solve writability issue in trilemma. L10-FePt is the great high magnetic anisotropy material. Therefore, the magnetic parameters of this material such as magnetocrystalline anisotropy constant, Ku, saturation magnetization, Ms, and exchange coupling between a soft/hard interface, are important on magnetic material properties. In this work, the effects of magnetic parameters on magnetic properties of L10-FePt/Fe based ECC bilayer media are simulated by the object oriented micromagnetic framework based on Landau-Lifshitz-Gilbert equation. The ECC bilayer media can reduce switching field, Hsw, of media lower than available writing head field. Hence, writability issues of high Ku media can be achieved. Reducing Hsw of ECC bilayer media obtains from lower Ku and higher Ms values. This work can achieve writing capability of a future magnetic recording system.

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Contribution of the easy axis orientation, anisotropy distribution and dot size on the switching field distribution of bit patterned media

Applied Physics Letters ◽

10.1063/1.3623752 ◽

2011 ◽

Vol 99 (6) ◽

pp. 062505 ◽

Cited By ~ 24

Author(s):

Jehyun Lee ◽

Christoph Brombacher ◽

Josef Fidler ◽

Barbara Dymerska ◽

Dieter Suess ◽

...

Keyword(s):

Field Distribution ◽

Easy Axis ◽

Switching Field ◽

Bit Patterned Media ◽

Axis Orientation ◽

Patterned Media ◽

Orientation Anisotropy ◽

Switching Field Distribution

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Design and Micromagnetic Simulation of Fe/L10-FePt/Fe Trilayer for Exchange Coupled Composite Bit Patterned Media at Ultrahigh Areal Density

Advances in Materials Science and Engineering ◽

10.1155/2015/504628 ◽

2015 ◽

Vol 2015 ◽

pp. 1-5 ◽

Cited By ~ 5

Author(s):

Warunee Tipcharoen ◽

Arkom Kaewrawang ◽

Apirat Siritaratiwat

Keyword(s):

Exchange Coupling ◽

Single Layer ◽

Areal Density ◽

Interlayer Exchange Coupling ◽

Magnetic Media ◽

Recording Technology ◽

Bit Patterned Media ◽

Patterned Media ◽

Interlayer Exchange ◽

Exchange Coupled Composite

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.

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L10-CoPt Bit Patterned Media with Tilted Easy Axis for Ultrahigh Areal Density over 2.5 Tb/in2

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.931-932.1255 ◽

2014 ◽

Vol 931-932 ◽

pp. 1255-1259

Author(s):

Arkom Kaewrawang

Keyword(s):

Easy Axis ◽

Areal Density ◽

Disk Drive ◽

Simulation Software ◽

Bit Patterned Media ◽

Patterned Media ◽

Perpendicular Media ◽

Data Density ◽

Superparamagnetic Limit ◽

The One

Ultrahigh areal density is the key target of hard disk drive technology. Hence, writing field strength from head and switching field, Hsw, of media should be improved. In this work, we propose the one of alternative method to increase data density and reduce Hsw of the media by using tilted easy axis technology for bit patterned media (BPM) at areal density beyond 2.5 Tb/in2. Moreover, transition noise and superparamagnetic limit have been eliminated owing to characteristics of BPM. The effect of exchange coupled between adjacent bits, Adot, of tilted easy axis of BPM is analyzed by micromagnetic simulation software - the object oriented micromagnetic framework based on Landau-Lifshitz-Gilbert equation. The BPM with tilted easy axis perform clearly the reduction of Hsw below perpendicular media and available writing head field. The Adot of BPM has no effect on decreasing Hsw. Anisotropy and Zeeman energy density of BPM with tilted easy axis are higher and lower than perpendicular BPM, respectively. Thereby, BPM with tilted easy axis have high potentiality to improve Hsw of media at ultrahigh data density.

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