CN1695183A - 具有按照反平行磁化取向的反铁磁双层结构的存储层的热辅助记录介质 - Google Patents
具有按照反平行磁化取向的反铁磁双层结构的存储层的热辅助记录介质 Download PDFInfo
- Publication number
- CN1695183A CN1695183A CNA038248778A CN03824877A CN1695183A CN 1695183 A CN1695183 A CN 1695183A CN A038248778 A CNA038248778 A CN A038248778A CN 03824877 A CN03824877 A CN 03824877A CN 1695183 A CN1695183 A CN 1695183A
- Authority
- CN
- China
- Prior art keywords
- layer
- recording medium
- sublayer
- magnetization
- double
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 230000005415 magnetization Effects 0.000 title claims abstract description 32
- 230000005290 antiferromagnetic effect Effects 0.000 title claims description 17
- 238000003860 storage Methods 0.000 title abstract description 15
- 230000005291 magnetic effect Effects 0.000 claims abstract description 60
- 239000000203 mixture Substances 0.000 claims abstract description 8
- 238000009825 accumulation Methods 0.000 claims description 39
- 230000008878 coupling Effects 0.000 claims description 35
- 238000010168 coupling process Methods 0.000 claims description 35
- 238000005859 coupling reaction Methods 0.000 claims description 35
- 238000000034 method Methods 0.000 claims description 22
- 238000003475 lamination Methods 0.000 claims description 12
- 229910045601 alloy Inorganic materials 0.000 claims description 9
- 239000000956 alloy Substances 0.000 claims description 9
- 229910052761 rare earth metal Inorganic materials 0.000 claims description 9
- 229910052723 transition metal Inorganic materials 0.000 claims description 9
- 150000003624 transition metals Chemical class 0.000 claims description 6
- 230000008569 process Effects 0.000 claims description 5
- 238000004519 manufacturing process Methods 0.000 claims description 3
- -1 rare-earth transition metal Chemical class 0.000 claims description 3
- 239000010409 thin film Substances 0.000 claims description 3
- 229910052771 Terbium Inorganic materials 0.000 claims description 2
- 230000002349 favourable effect Effects 0.000 claims description 2
- 229910052742 iron Inorganic materials 0.000 claims description 2
- 230000008901 benefit Effects 0.000 abstract description 8
- 238000001816 cooling Methods 0.000 abstract description 5
- 230000015572 biosynthetic process Effects 0.000 abstract description 2
- 239000010410 layer Substances 0.000 description 119
- 230000007704 transition Effects 0.000 description 10
- 230000035945 sensitivity Effects 0.000 description 7
- 230000005294 ferromagnetic effect Effects 0.000 description 6
- 239000011229 interlayer Substances 0.000 description 6
- 239000000463 material Substances 0.000 description 6
- 150000002910 rare earth metals Chemical class 0.000 description 6
- 238000013459 approach Methods 0.000 description 5
- 230000000694 effects Effects 0.000 description 5
- 229910002546 FeCo Inorganic materials 0.000 description 4
- 239000010408 film Substances 0.000 description 4
- 230000008859 change Effects 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 230000005381 magnetic domain Effects 0.000 description 3
- 230000003068 static effect Effects 0.000 description 3
- 239000000758 substrate Substances 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 238000010276 construction Methods 0.000 description 2
- 238000001514 detection method Methods 0.000 description 2
- 230000006870 function Effects 0.000 description 2
- 230000002452 interceptive effect Effects 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 230000003287 optical effect Effects 0.000 description 2
- 238000005457 optimization Methods 0.000 description 2
- 230000004044 response Effects 0.000 description 2
- TVEXGJYMHHTVKP-UHFFFAOYSA-N 6-oxabicyclo[3.2.1]oct-3-en-7-one Chemical compound C1C2C(=O)OC1C=CC2 TVEXGJYMHHTVKP-UHFFFAOYSA-N 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 229910000531 Co alloy Inorganic materials 0.000 description 1
- 229910018936 CoPd Inorganic materials 0.000 description 1
- 229910001030 Iron–nickel alloy Inorganic materials 0.000 description 1
- ORILYTVJVMAKLC-UHFFFAOYSA-N adamantane Chemical compound C1C(C2)CC3CC1CC2C3 ORILYTVJVMAKLC-UHFFFAOYSA-N 0.000 description 1
- 229910001573 adamantine Inorganic materials 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 230000003321 amplification Effects 0.000 description 1
- 230000005303 antiferromagnetism Effects 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000005347 demagnetization Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 230000002708 enhancing effect Effects 0.000 description 1
- 230000005293 ferrimagnetic effect Effects 0.000 description 1
- 230000005308 ferrimagnetism Effects 0.000 description 1
- 239000003302 ferromagnetic material Substances 0.000 description 1
- 210000004907 gland Anatomy 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 229910052741 iridium Inorganic materials 0.000 description 1
- 239000004922 lacquer Substances 0.000 description 1
- 230000005389 magnetism Effects 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 229910052748 manganese Inorganic materials 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 229910052750 molybdenum Inorganic materials 0.000 description 1
- 229910052758 niobium Inorganic materials 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
- 229910052762 osmium Inorganic materials 0.000 description 1
- 229920000515 polycarbonate Polymers 0.000 description 1
- 239000004417 polycarbonate Substances 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 229910052702 rhenium Inorganic materials 0.000 description 1
- 229910052703 rhodium Inorganic materials 0.000 description 1
- 238000004088 simulation Methods 0.000 description 1
- 238000004528 spin coating Methods 0.000 description 1
- 238000004544 sputter deposition Methods 0.000 description 1
- 229910052715 tantalum Inorganic materials 0.000 description 1
- 229910052721 tungsten Inorganic materials 0.000 description 1
- 229910052720 vanadium Inorganic materials 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B11/00—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor
- G11B11/10—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field
- G11B11/105—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field using a beam of light or a magnetic field for recording by change of magnetisation and a beam of light for reproducing, i.e. magneto-optical, e.g. light-induced thermomagnetic recording, spin magnetisation recording, Kerr or Faraday effect reproducing
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B11/00—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor
- G11B11/10—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field
- G11B11/105—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field using a beam of light or a magnetic field for recording by change of magnetisation and a beam of light for reproducing, i.e. magneto-optical, e.g. light-induced thermomagnetic recording, spin magnetisation recording, Kerr or Faraday effect reproducing
- G11B11/10582—Record carriers characterised by the selection of the material or by the structure or form
- G11B11/10584—Record carriers characterised by the selection of the material or by the structure or form characterised by the form, e.g. comprising mechanical protection elements
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B11/00—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor
- G11B11/10—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field
- G11B11/105—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field using a beam of light or a magnetic field for recording by change of magnetisation and a beam of light for reproducing, i.e. magneto-optical, e.g. light-induced thermomagnetic recording, spin magnetisation recording, Kerr or Faraday effect reproducing
- G11B11/10582—Record carriers characterised by the selection of the material or by the structure or form
- G11B11/10586—Record carriers characterised by the selection of the material or by the structure or form characterised by the selection of the material
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/62—Record carriers characterised by the selection of the material
- G11B5/64—Record carriers characterised by the selection of the material comprising only the magnetic material without bonding agent
- G11B5/66—Record carriers characterised by the selection of the material comprising only the magnetic material without bonding agent the record carriers consisting of several layers
- G11B5/676—Record carriers characterised by the selection of the material comprising only the magnetic material without bonding agent the record carriers consisting of several layers having magnetic layers separated by a nonmagnetic layer, e.g. antiferromagnetic layer, Cu layer or coupling layer
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B11/00—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor
- G11B11/10—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field
- G11B11/105—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field using a beam of light or a magnetic field for recording by change of magnetisation and a beam of light for reproducing, i.e. magneto-optical, e.g. light-induced thermomagnetic recording, spin magnetisation recording, Kerr or Faraday effect reproducing
- G11B11/10582—Record carriers characterised by the selection of the material or by the structure or form
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B2005/0002—Special dispositions or recording techniques
- G11B2005/0005—Arrangements, methods or circuits
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B2005/0002—Special dispositions or recording techniques
- G11B2005/0005—Arrangements, methods or circuits
- G11B2005/0021—Thermally assisted recording using an auxiliary energy source for heating the recording layer locally to assist the magnetization reversal
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S428/00—Stock material or miscellaneous articles
- Y10S428/90—Magnetic feature
Abstract
本发明涉及一种包括存储层的热辅助记录介质,所述存储层包括由具有基本相同组成的反铁磁耦合的第一(SL1)和第二(SL3)层构成的双层结构,其中所述第一和第二层适于具有反平行的磁化取向。由于在冷却期间所述两个层具有反平行的磁化取向,所以子域信息被抑制并且能够以减小的外部场对均匀磁化的域进行写入。这对于便携式应用的功耗具有主要的优点,并且能够使磁场线圈以较高的数据率进行记录。
Description
本发明涉及一种热辅助记录介质,例如磁光或热辅助磁记录盘,包括存储层,用于将信息热辅助地写入到所述记录介质中。
磁光(MO)存储与磁场相结合的应用聚焦激光束。读回信号是基于反射光的极性变化得到的。MO记录相比于相变记录的优点在于:能够写入和读出具有远小于衍射极限的尺寸的标记。为了扩宽MO记录的应用领域,应该进一步提高面密度和改进记录层的场灵敏度。在MO记录中,小数据位是通过使用激光脉冲磁场调制(LP-MFM)写入的。在LP-MFM中,位过渡是通过磁场切换和由激光切换引入的温度梯度确定的。为了读出以这种方式记录的小月牙形标记,必须使用磁超分辨率(MSR)或域扩展(DomEx)方法。这些技术基于具有若干层磁静态或交换耦合稀土过渡金属(RE-TM)层的记录介质。盘上的读出层在读取期间屏蔽邻近位(MSR)或以激光点的中心扩展域(DomEx)。DomEx较之MSR的优点在于具有远小于衍射极限的尺寸的数据位能够以与具有与衍射极限光斑相当的尺寸的数据位相似的信噪比(SNR)检测到。
AC-MAMMOS(交流磁放大磁光系统)是基于磁静态耦合存储和扩展或读出层的DomEx方法。在AC-MAMMOS盘中,存储层中的磁畴通过非磁性夹层与读出层相耦接,并且被复制的磁畴通过使用外部磁场而被扩展至大于激光点的直径的尺寸。在读出处理中,较小的记录域被选择性的复制到读出层,然后通过外部磁场在读出层中扩展。因此,通过再现扩展的域就可获得大信号。之后,通过应用反向外部场而可以除去读出层中的扩展域。
在ZF-MAMMOS(零磁场MAMMOS)中,一后来发展的DomEx技术,存储层中的磁畴通过磁性触发层而与读出层相耦接,而且复制的磁畴扩展至与激光点的直径相当的尺寸,并且随后作为消磁的变化平衡的结果,其将发生瓦解,且杂散场强加于畴壁。对于读出过程不需要外部场。
畴壁偏移检测(DWDD)是基于交换耦合存储和读出层的DomEx方法。在DWDD中,作为交换耦合力的结果,记录在存储层中的标记通过中间磁性切换层被转移给读出或偏移层。当再现激光点照射到盘的轨迹上时,温度升高。当切换层超过居里温度时,磁化消失,从而使得每层之间的交换耦合力消失。交换耦合力是在偏移层中保持转移的标记的力之一。当它消失时,偏移层中的畴壁转移至具有低畴壁能量的高温部分,从而允许小记录标记能够扩展。这允许用激光束进行读取,即使记录是以高密度进行的。
热辅助或热量辅助磁记录在记录介质上与用于写入的磁场相结合地应用小激光光斑。然而,与MO记录相反,读回信号是通过磁阻检测器基于记录标记的杂散场的检测获得的。对于热辅助磁记录,存储层应该使得能优选地以低记录场在提高的温度下高密度写入。
应用在MO记录介质中的存储和读出层是基于类似TbFeCo和GdFeCo的稀土(RE)过渡金属(TM)合金获得的。为了进行热辅助磁记录,TbFeCo合金也形成感兴趣的记录材料。RE-TM层为亚铁磁的,其RE和TM亚点阵的磁化方向相对。亚铁磁性是在那些反铁磁材料中出现的磁化形式,其中精微磁矩被反平行的对齐,但不相等。通过适当的选择RE元素和组分,能够根据磁性以特定的各向异性、磁化和温度设计铁磁物质。对于存储层,以获得垂直的磁各向异性这样一种方式选择组分。通过在彼此的顶部沉积两层RE-TM层,可容易地对其进行交换耦合。最低的能量状态是两层中的亚点阵具有相同的取向。然而,当一层富含RE,而另一层富含TM时,两层中的净磁化将是相反的。这种RE-TM层的直接交换耦合和非磁性电介质层上的RE-TM层的静磁耦合在MO记录中形成所有已知超分辨率读出技术的基础。TbFeCo/GdFeCo二层或双层的直接交换耦合也用于提高用于LP-MFM记录的介质的场灵敏度。
对于铁磁薄膜,通过在例如薄非磁性Ru层上耦合两个铁磁薄膜也可以获得反铁磁或铁磁性能。该效果适用于偏移传感器和磁性随机存取存储器(MRAMs)中的GMR和TMR元素。硬盘存储器的铁磁存储层的反铁磁耦合的应用也是本领域公知的并且适用于现有的硬盘驱动器(HDD)产品以增加存储层的磁稳定性。在这种情况下,两个铁磁平面内磁化Co合金膜被反铁磁性地耦合在Ru层上。文献US5756202披露了一种在例如Ru层上反铁磁耦合两个铁磁垂直磁化Co/Pt多层叠层,其可用于超分辨率和直接重写MO记录。
此外,文献US6150038披露了一种具有可由两个子层构成的存储层的DWDD介质。这两个子层具有以这样一种方式调节的组分,即在从室温至写入温度的温度范围内一个子层富含RE,而另一个富含TM。通过对两个子层进行反平行的磁化,扩展层上的杂散场较小,这导致较好的扩展处理。作为例子,提及了TbFeCo存储层和GdFeCo层的结合。这能够在TbFeCo层中以较低的场写入数据。然而,该方法的主要缺点是对于存储层必须使用具有显著不同组分的两个RE-TM子层。如果其中一个层在高各向异性方面已经被最佳化,则另一层将具有较低的各向异性。当必须写入小数据位和将其保持稳定时,该较低的平均各向异性将产生问题。
LP-MFM写入是用于增加线性密度的非常有效的记录方法。然而,LP-MFM技术需要用于调节外部场的磁场线圈。驱动磁场线圈的功耗对于便携式应用将会产生一个问题。此外,对于高数据写入应用,在充分短的时间内切换所需的高电流变得日益困难。两个问题都可通过使用具有增加的场灵敏度的介质来解决。例如,将场灵敏度增加两倍意味着通过线圈的电流可减小两倍,而功率可以减小四倍。
传统的TbFeCo存储介质需要16kA/m或更多的磁场。已知多个方法能够将场灵敏度增加至8kAm的水平。例如通过在适当的时刻在溅射腔中引入一些氮而能够修改TbFeCo层的(多个)界面,或者可将TbFeCo层交换耦合至薄的GdFeCo层,其在居里温度附近具有小的各向异性。然而,这些方法的问题在于它们减小了存储层的有效各向异性。该各向异性是一个重要参数,因为它确定位过渡的宽度、规则性和稳定性。因此,如果这些方法用于例如每平方英寸10-100Gb的高记录密度,则是有问题的。
位过渡的规则性和稳定性问题对于以每平方英寸10-100Gb的非场灵敏度增强存储层来说也可能变得相关。在读出温度下,存储层的磁化被局部增大,从而在畴壁上产生消磁力。如果各向异性和锁住力不足够强,则这些消磁力可将畴壁移至略微不同的位置,从而导致增加的过渡抖动电平。在MO中进行热辅助写入期间以及在热辅助磁记录中也可出现类似的效应。在冷却下来的过程中,由于畴壁上的消磁力,在存储层中刚形成的过渡的位置可偏移或变形。在读出过程中,这可导致位错误。
本发明的目的是提供一种热辅助记录介质和制造方法,借助于它能够降低磁线圈所需的功耗并能使位过渡稳定以允许高记录密度。
该目的是通过权利要求1所述的热辅助记录介质和权利要求11所述的制造方法实现的。
因此,具有基本相同的子层磁性质的反铁磁双层结构被提议作为用于热辅助记录的存储层。由于在冷却过程中两个子层具有反平行的磁化取向,所以消磁磁场被减小且子畴形成被抑制。所以,可用减小的外部场对均匀磁化的域进行写入。这对于便携式应用的功耗具有主要的优点并且能够使磁场线圈以较高的数据率进行记录。此外,减小消磁磁场在记录期间导致更清晰的过渡和减小的过渡偏移。过渡偏移也将变得独立于刚记录的数据图案。这些效果能够支持记录密度的增加。由存储层产生的较低的杂散场在DomEx叠层布置中是有利的,例如在DWDD应用中。因为当子层处于反平行的对齐方式时,杂散场不依赖于层的组成,所以可以在获得最高可能的存储密度而没有如单层情况中对杂散场效应妥协的方面使组成最佳化。
具有基本相同的磁性质的两个子层的反铁磁耦合可通过在适当材料和厚度的非磁性金属夹层上耦合所述子层来获得。优选的是将Ru用于具有约0.9nm厚度的夹层,因为该材料并具有该厚度的层引入了强的反铁磁耦合。其它耦合材料例如V、Cr、Mn、Cu、Nb、Mo、Rh、Ta、W、Re、Os、Ir及其混合物原则上也能使用。
存储层优选的是基于类似TbFeCo的具有高垂直各向异性和在200-400℃的写入温度附近的居里温度的稀土过渡金属合金。然而类似CoPd多层或CoPdX、CoPtX、FePtX合金的具有垂直各向异性的其它存储材料也能应用,其中X表示小百分比的添加物。
非磁性夹层上的耦合强度可通过在存储子层和夹层之间选择适当的界面层而得到增强。对于TbFeCo存储层,可使用由Tb、Fe、Co或FeCo形成的界面层。界面层也可用于防止在热辅助记录期间夹层向存储子层扩散。
所述反平行取向在室温和写入温度之间的温度范围中应该与第一和第二层的最低能量状态对应。这对于典型的TbFeCo存储层厚度和Ru上的耦合强度来说是容易实现的,因为在冷却过程中,当刚通过两个子层的最低居里温度时,反铁磁耦合就控制了任何其它静磁交互作用。为了能够进行写入,可通过提供具有略微不同性质(例如厚度)的层和/或使第一和第二层具有不同的居里温度来区别第一和第二层的性质。
此外,所述双层结构可并入MSR或DomEx叠层中。下面,将参照附图在优选实施例的基础上更详细地说明本发明,其中:
图1表示MO记录结构的示意图;
图2A、2B和2C表示根据本发明优选实施例的存储层的示意结构;
图3A和3B表示根据本发明优选实施例的双层结构的反平行取向;
图4表示TbFeCo/Ru/TbFeCo层堆叠的滞后回线;
图5表示用于传统的MO记录的盘上的层结构;
图6表示以DWDD读出进行MO记录的盘上的层结构;
图7表示用于热辅助磁记录的盘上的层结构。
在图1中,示出了使用光数据存储介质5的MO记录和读取系统的一个实施例。介质5包括记录叠层9并且具有覆盖叠层7,其对于聚焦辐射束1是透明的。辐射束1的波长为405nm。覆盖层7具有10μm的厚度。分别通过溅射和旋涂在基底8上连续形成所述记录叠层9种覆盖叠层7。具有数值孔径NA=0.85的物镜2的光头3设置在所述光学数据存储介质5的覆盖层7一侧,在记录期间聚焦辐射束1从所述物镜2发射。光头3适于以距介质5的最外表面为15μm的自由工作距离进行记录/读取。光头3包括有MFM线圈4,用于进行LP-MFM写入。
图2A、2B和2C表示根据本发明的优选实施例提出的双层结构。根据图2A,TbFeCo/Ru/TbFeCo形式的合成反铁磁耦合双层结构被提出作为存储层SL。选择RE-TM合金例如TbFeCo的参数以便在室温和居里或写入温度之间的温度范围中以最低能量状态获得反平行结构。所述参数可以是TbFeCo层的磁化乘厚度的乘积、矫顽力、Ru层上的反铁磁耦合强度、等等。图2B表示TbFeCo/FeCo/Ru/TbFeCo形式的合成反铁磁耦合双层结构,其中在TbFeCo和Ru的界面处添加薄的FeCo合金层以增加耦合强度。图2C表示存储层的第三实施例,其中子层SL1和SL2由例如一Tb/FeCo或TbFeCo/Pt多层膜构成。多层的应用可以具有在短波长下获得高的垂直各向异性或增加的克尔旋转的优点。
在LP-MFM写入期间外部场的一个功能是将加热区域中的磁化方向定在所要求的方向上。由于各向异性和磁化在居里温度以下是小的这样的事实,该功能可通过非常小的外部场来实现。在冷却期间,磁化增强并且刚记录的区域可能分裂为多个子域。这在读出期间将导致较低的载体电平和增加的噪音。可通过使用充分高的外部场来抑制子域信息。因此,最佳写入场主要是通过该第二过程确定的。
图3A和3B表示两个子层SL1、SL3的两个反平行取向,用于在存储层中存储二进制信息状态。在图3A中,反平行磁性取向指向耦合层SL2,而在图3B中,反平行磁性取向背向耦合层SL2。由于两个子层SL1、SL3的这种反平行取向,整体磁化在前述的温度范围内是小的。原则上将不需要外部场来抑制子域信息。
为了能够在居里温度附近进行写入,两个子层SL1、SL3的性质应该被选择得略微不同。一种可能性是将两个TbFeCo层SL1、SL3的厚度选择得略微不同。另一种可能性是将居里温度选择得略微不同使得具有较高居里温度的层能够与外部场对齐,并且在冷却过程中,另一层调准为反平行。盘或记录介质上的二进制“1”和“0”状态可分别对应于图3A和3B中的状态。
所提出的双层结构的一个主要优点在于TbFeCo层SL1、SL3的组成可被最佳选择用于获得最低的过渡抖动和由此获得最高的密度。因此,TbFeCo层SL1、SL3相比于已知的方法都能具有高的各向异性,在所述已知方法中GdFeCo压盖层具有低得多的各向异性。
图4表示20nm Si3N4/15nm TbFeCo/0.9nm Ru/10nm TbFeCo/20nmSi3N4层堆叠的滞后回线,其是以室温和633nm波长在克尔滞后回线跟踪器中测量的。在图中,水平轴表示以kA/m为单位的外部场H,垂直轴表示以度为单位的克尔旋转。箭头表示沿滞后回线的某一分支的磁场的扫描方向。两个TbFeCo子层的补偿温度和居里温度为20℃和220℃。在高于1400kA/m的磁场下,两个子层被定位在外部场的方向中。除了主滞后回线外,还示出了一个次磁滞回线。该回线是通过在将两个层定位在外部场的方向上的一个值和将所述层处于反平行取向上的值之间改变场强测量的。该主回线和次回线显示对于磁化、子层厚度和矫顽力的这种特殊组合在零磁场处存在两个稳定的平行状态和两个稳定的反平行状态。对于子层的较大反铁磁耦合强度和较小矫顽力,只有反平行状态将在零磁场处变得稳定。克尔滞后回线还显示克尔旋转的幅度对于反平行来说比对于平行结构的子层要大。这与在叠层中的各种材料的电介质张量基础上进行的模拟相一致。可利用该效应来增加存储层的MO读出信号,所述存储层具有以反平行磁化对齐方式的子层。
图5表示根据图1的结构的用于覆盖层入射MO记录的介质。所述叠层包括由例如AlCr或Ag构成的金属散热层(M)、由Si3N4形成的透明干涉层(I1、I2)、由TbFeCo构成的存储子层(SL1、SL3)和Ru耦合层(SL2)。以这样一种方式选择TbFeCo的组成,即居里温度略微不同但接近于写入温度。两个子层的厚度被选择得基本相同使得当子层处于反平行对齐方式时,对于存储层可获得较小的整体磁化。使用注射模制的聚碳酸酯基底(S)和由光聚合漆形成的旋涂覆盖层C。干涉层和金属层的厚度关于读出信号和写入期间的热响应最佳化。
所提出的双层结构也可用于MSR叠层。在该情况下,TbFeCo层SL1、SL3之一可以传统的方式与其余的MSR叠层交换耦合。如果关于AC-MAMMOS读出使用了磁静态耦合,则必需使两个TbFeCo层SL1、SL3的磁性质在读出温度下充分不同以产生所需的杂散场。因此,必须在接近于写入温度以获得增强的场灵敏度的低整体磁化和在读出温度下用于获得良好的MAMMOS响应的充分高整体磁化和杂散场之间找出一个折衷。
对于DWDD叠层中的反铁磁耦合存储层的应用,在读出温度下的低杂散场形成一个主要优点,因为存储层杂散场可不再破坏读出层中的扩展过程。在图6中示出了一个DWDD实施例。对于DWDD读出,在图5所示的叠层中并入有切换(SW)、控制(CL)和偏移或读出(D)层。存储层SL1以传统的方式与切换层交换耦合。这能够基于RE-TM薄膜将新的存储层结构与标准的DWDD层堆叠结合起来。例如,TbFeAl合金可用于切换层,TbFe合金可用于控制层,而GdFeAl层可用于偏移层。以这样一种方式选择TbFeCo存储子层的组成,使得居里温度略微不同但接近于写入温度。两个子层的厚度可被选择得基本相同使得在接近于写入温度以及在读出温度下获得小的整体磁化。将Ru层用作耦合层(SL2)。
图7表示用于热辅助磁记录的叠层结构。在存储层和散热层之间,包括例如NiFe或CoZrNb的软磁层(SM)以增强存储层上的写入头的场。在存储层的顶部,并入有一薄的类似金刚石的碳膜C以在用滑动头进行写入和读取期间获得所需的摩擦性质。由于记录头与介质非常接近,所以存储子层SL1主要包括在写入和读出过程中。所以即使当子层确切具有某些性质时,与MO记录的情况相反,仍能够在热辅助磁记录期间进行写入和读取。
注意本发明不局限于前述的特定层结构和记录配置。可使用任何适当的存储层材料来获得具有反平行配置的合成反铁磁耦合双层结构。代替覆盖层入射MO记录结构,也可以使用基底入射的结构。因此所述优选实施例可在后附权利要求的范围内变化。
Claims (12)
1.一种记录介质,包括存储层,用于向所述记录介质热辅助的写入信息,所述存储层包括至少包含两个子层的叠层,其中所述子层是通过非磁性层反铁磁耦合的,并且其中至少在低于写入温度的温度范围内,存储层的整体磁化幅度基本上小于每个子层的磁化幅度,并且所述子层具有在室温周围有利的各向异性和垂直于薄膜平面的磁化取向。
2.根据权利要求1所述的记录介质,其中所述非磁性层是Ru层。
3.根据权利要求1或2所述的记录介质,其中所述非磁性层具有位于0.5和1.5nm之间的厚度。
4.根据权利要求1所述的记录介质,其中所述子层由稀土过渡金属合金构成,所述合金至少包括Tb和Fe作为元素。
5.根据权利要求1所述的记录介质,其中所述子层在与非磁性层的界面处包括薄的过渡金属层。
6.根据前述任何一个权利要求所述的记录介质,其中所述子层适于具有不同的厚度。
7.根据前述任何一个权利要求所述的记录介质,其中所述子层适于具有不同的居里温度。
8.根据前述任何一个权利要求所述的记录介质,其中记录叠层的克尔旋转或克尔椭圆率对于反平行的子层磁化比对于平行取向的子层磁化具有更大的幅度。
9.根据前述任何一个权利要求所述的记录介质,其中所述双层结构被结合在MSR叠层中。
10.根据权利要求9所述的记录介质,其中所述子层和非磁性层是DWDD叠层的一部分,并且适应于这样一种方式,即存储层的磁化幅度作为一个整体在读出温度下基本上小于每个子层的磁化幅度。
11.根据权利要求9所述的记录介质,其中所述记录介质是MAMMOS记录介质。
12.一种制造磁光记录介质的方法,所述方法包括步骤:
a.通过产生反铁磁耦合的双层结构来形成存储层,所述双层结构包括两个具有基本相同组成的磁性子层和一个非磁性耦合层;和
b.设置所述双层结构的所述磁性子层和非磁性耦合层的参数,以便在从用于热辅助记录的写入温度冷却下来的过程中获得反平行取向的磁化。
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP02079582.9 | 2002-11-01 | ||
EP02079582 | 2002-11-01 |
Publications (1)
Publication Number | Publication Date |
---|---|
CN1695183A true CN1695183A (zh) | 2005-11-09 |
Family
ID=32187232
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CNA038248778A Pending CN1695183A (zh) | 2002-11-01 | 2003-09-26 | 具有按照反平行磁化取向的反铁磁双层结构的存储层的热辅助记录介质 |
Country Status (8)
Country | Link |
---|---|
US (1) | US20060062132A1 (zh) |
EP (1) | EP1563492A1 (zh) |
JP (1) | JP2006505083A (zh) |
KR (1) | KR20050084903A (zh) |
CN (1) | CN1695183A (zh) |
AU (1) | AU2003263528A1 (zh) |
TW (1) | TW200415574A (zh) |
WO (1) | WO2004040558A1 (zh) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN107523796A (zh) * | 2017-07-21 | 2017-12-29 | 华侨大学 | 一种具有间隔层的稀土‑过渡合金复合材料的制备方法 |
Families Citing this family (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2002103694A1 (en) * | 2001-06-19 | 2002-12-27 | Koninklijke Philips Electronics N.V. | Method and apparatus for reading from a domain expansion recording medium |
JP2005222669A (ja) * | 2004-01-05 | 2005-08-18 | Fujitsu Ltd | 磁気記録媒体および磁気記憶装置 |
KR20070026880A (ko) * | 2004-07-13 | 2007-03-08 | 더 리젠츠 오브 더 유니버시티 오브 캘리포니아 | 교환 바이어스 기반의 다상태 자기 메모리와 로직 디바이스및 자기적으로 안정된 자기 기억장치 |
KR101323717B1 (ko) * | 2007-09-14 | 2013-10-30 | 삼성전자주식회사 | 자구벽 이동을 이용한 정보 저장 장치 및 그 제조 방법 |
US7755861B1 (en) | 2007-12-06 | 2010-07-13 | Western Digital (Fremont), Llc | Method and system for providing a magnetic recording media |
US7862912B2 (en) * | 2008-03-04 | 2011-01-04 | Hitachi Global Storage Technologies Netherlands B.V. | Perpendicular magnetic recording medium and system with low-curie-temperature multilayer for heat-assisted writing and/or reading |
JP5332676B2 (ja) * | 2009-02-09 | 2013-11-06 | 富士電機株式会社 | 磁気記録媒体 |
US9792971B2 (en) | 2014-07-02 | 2017-10-17 | Samsung Electronics Co., Ltd. | Method and system for providing magnetic junctions with rare earth-transition metal layers |
TWI616872B (zh) * | 2016-09-09 | 2018-03-01 | 國立中興大學 | Heat assisted magnetic recording medium |
Family Cites Families (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1143434A3 (en) * | 1992-08-28 | 2001-12-12 | Canon Kabushiki Kaisha | A magnetooptical recording medium and information recording and reproducing methods using the recording medium |
US5723978A (en) * | 1994-02-24 | 1998-03-03 | Kabushiki Kaisha Toshiba | Photo-inducible magnetic exchange coupling device |
JPH08106660A (ja) * | 1994-10-05 | 1996-04-23 | Canon Inc | 光磁気記録媒体及び該媒体を用いた情報再生方法 |
JP3990128B2 (ja) * | 2001-09-14 | 2007-10-10 | 株式会社東芝 | 磁気記録装置 |
DE10297472T5 (de) * | 2001-11-30 | 2004-11-18 | Seagate Technology Llc, Scotts Valley | Antiparallel ferromagnetisch gekoppelte Vertikalmagnetaufzeichnungsmedien |
-
2003
- 2003-09-26 AU AU2003263528A patent/AU2003263528A1/en not_active Abandoned
- 2003-09-26 US US10/532,920 patent/US20060062132A1/en not_active Abandoned
- 2003-09-26 EP EP03809811A patent/EP1563492A1/en not_active Withdrawn
- 2003-09-26 KR KR1020057007564A patent/KR20050084903A/ko not_active Application Discontinuation
- 2003-09-26 CN CNA038248778A patent/CN1695183A/zh active Pending
- 2003-09-26 JP JP2004547850A patent/JP2006505083A/ja not_active Withdrawn
- 2003-09-26 WO PCT/IB2003/004275 patent/WO2004040558A1/en not_active Application Discontinuation
- 2003-10-29 TW TW092130059A patent/TW200415574A/zh unknown
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN107523796A (zh) * | 2017-07-21 | 2017-12-29 | 华侨大学 | 一种具有间隔层的稀土‑过渡合金复合材料的制备方法 |
CN107523796B (zh) * | 2017-07-21 | 2019-07-05 | 华侨大学 | 一种具有间隔层的稀土-过渡合金复合材料的制备方法 |
Also Published As
Publication number | Publication date |
---|---|
WO2004040558A1 (en) | 2004-05-13 |
TW200415574A (en) | 2004-08-16 |
US20060062132A1 (en) | 2006-03-23 |
KR20050084903A (ko) | 2005-08-29 |
JP2006505083A (ja) | 2006-02-09 |
AU2003263528A1 (en) | 2004-05-25 |
EP1563492A1 (en) | 2005-08-17 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
Tsunashima | Magneto-optical recording | |
US6834026B2 (en) | Method for thermally-assisted recording on a magnetic recording disk | |
JPH06500194A (ja) | 高い記憶密度と直接重ね書きケイパビリティを有する熱磁気記録システム | |
US6633514B1 (en) | Magneto-optical reproducing method using a plural of different reproducing beams | |
CN1695183A (zh) | 具有按照反平行磁化取向的反铁磁双层结构的存储层的热辅助记录介质 | |
US6504665B1 (en) | Method and apparatus for magnetic recording | |
JPH11511282A (ja) | 光磁気記録媒体及びその記録再生方法 | |
JP2008269789A (ja) | 熱磁気記録媒体 | |
US6868048B1 (en) | Data storage system having thermally activated readout | |
JP3108397B2 (ja) | 光磁気記録媒体 | |
CN1666273A (zh) | 具有反铁磁耦合畴扩展双层结构的磁光记录介质 | |
JP3811880B2 (ja) | 磁気記録媒体 | |
Lin et al. | High magnetization exchange-couple double-layer TbFeCo for magnetic flux reading optical recording | |
US7295404B2 (en) | Magnetic recording medium for perpendicular recording and magnetic storage apparatus using the same | |
OUCHI | Review on recent developments of perpendicular recording media | |
KR100625706B1 (ko) | 자기 기록 매체 및 그 자기 기록 방법 | |
JP2000067425A (ja) | 磁気記録媒体 | |
JP3381960B2 (ja) | 光磁気記録媒体 | |
Kryder | Magnetic information storage | |
CN1225729C (zh) | 用于高密度光磁混合记录的垂直磁化膜 | |
WO1999052101A1 (fr) | Support d'enregistrement magnetique et methode d'enregistrement | |
JP2674815B2 (ja) | 光磁気記録方法 | |
JPH10334443A (ja) | 垂直磁気記録媒体および記録再生装置 | |
JP3446297B2 (ja) | 光磁気記録媒体 | |
JP2000182232A (ja) | 磁気記録媒体 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
C06 | Publication | ||
PB01 | Publication | ||
C02 | Deemed withdrawal of patent application after publication (patent law 2001) | ||
WD01 | Invention patent application deemed withdrawn after publication |