CN100389458C - 用于磁记录的磁各向异性可调的层叠磁性薄膜 - Google Patents
用于磁记录的磁各向异性可调的层叠磁性薄膜 Download PDFInfo
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Abstract
公开了本发明的多个实施例,包括至少具有不同磁各向异性的两铁磁性叠层。远离记录磁头的独立磁性层选取具有较低的磁各向异性,可使在大致相同的磁头写入电流多磁性层发生磁性转换时,即使记录磁头磁场随着与磁头的距离的增加而降低也是如此。改进的转换产生了改进的磁记录性能。根据本发明的叠层磁介质在归一化直流消磁噪声与磁头写入电流的曲线中可以具有单一峰值,这表明在相同的磁头写入电流下,各非从属磁性层中的磁性转换被写入。结果,磁性脉冲宽度(PW50)得以降低,重写(OW)得以改善,介质信噪比(SoNR)得以改善。另外,一个或多个磁性叠层可以被反铁磁性(AF)耦合层结构所置换,该层结构具有被隔离层分隔的AFC主层和AFC从属层,选取隔离层以使AFC主层和AFC从属层形成反铁磁性耦合。
Description
技术领域
本发明涉及具有磁性叠层的磁性薄膜介质,并且涉及具有其中含有一个多个反铁磁耦合层结构的磁性叠层的磁性薄膜介质,特别是涉及这种介质中的多个薄膜所用材料的磁性能和选择。
背景技术
磁头和磁盘系统10的典型已有技术如图1所示。工作时,随着悬浮件13在磁盘16之上的飞浮,磁性传感器20被悬浮件13所支承。磁性传感器20通常称为“磁头”或者“滑块”,由执行写入磁性转变(写入磁头23)和读取磁性转变(读取磁头12)的任务的元件组成。来往于读取磁头和写入磁头12、23的电信号沿附着或埋置于悬浮件13的导电路径(引线)14传输。磁性传感器20位于距磁盘16中心不同径向距离之处上面,以便读取和写入环形磁道(未示出)。磁盘16被安装于主轴电机24所驱动的主轴18,使磁盘16旋转。磁盘16包括其上淀积有多层薄膜21的基片26。薄膜21包括铁磁材料,磁头23在其中记录对信息进行编码的磁性转变。
传统的磁盘16包括玻璃或者AlMg基片26,具有已被高度抛光的Ni3P无电涂层。磁盘16上的薄膜21通常包括铬或者铬合金底层以及至少一层各种钴基合金铁磁层。例如,通常所用的合金是CoPtCr。添加元素例如钽和硼经常用于磁性合金。保护外涂层用于改善耐磨性和耐蚀性。各种籽晶层、多底层和层叠磁性薄膜在已有技术中全有介绍。层叠磁性薄膜包括被非磁性隔离层分隔的铁磁性多层,最近提出了反铁磁性耦合。已知通过使用磁性叠层结构可以实现SNR的实质性提高。确信介质噪声的降低是由于各磁性层之间的交换耦合的降低。已经对为了降低噪声而使用叠层进行了广泛的研究,发现了有利的隔离层材料,包括Cr、CrV、Mo和Ru,以及几埃以上的隔离层厚度,由此导致各磁性层的最佳去耦合和最低的介质噪声。
在授予Carey等人的美国专利6280813中,介绍了一种层结构,包括通过非铁磁性耦合/隔离薄膜而反铁磁耦合在一起的至少两层铁磁薄膜。一般认为,随着耦合/隔离薄膜厚度的增大,交换耦合从铁磁性向反铁磁性振荡,并且耦合/隔离钌层的厚度优选6埃,因为在特定薄膜结构的振荡中该厚度对应于第一反铁磁性耦合峰。适合用做非铁磁性耦合/隔离薄膜的材料包括钌(Ru)、铬(Cr)、铑(Ru)、铱(Ir)、铜(Cu)及其合金。由于两种反铁磁性耦合薄膜的磁矩反平行取向,所以记录层的净剩余磁化强度-厚度之积(Mrt)是两种铁磁薄膜的Mrt值之差。Mrt的这种降低不会使记录介质的热稳定性降低,因为反铁磁性耦合薄膜中的晶粒体积积极地增加了。所述结构的一个实施例包括被钌隔离薄膜分隔的两种铁磁性CoPtCrB薄膜,该钌隔离薄膜具有的选择厚度使得两种CoPtCrB薄膜之间的反铁磁性交换耦合最大化。铁磁性顶层设计成具有比铁磁性底层更大的Mrt,以致在零外加磁场中的净磁矩很小,但不为零。Carey的’813专利也介绍了通过在耦合/隔离层与顶和/或底铁磁层之间增加薄的(5埃)铁磁性界面钴层,增强了反铁磁性耦合。该专利提到使用CoCr界面层,但并未详细说明。
在授予Doerner等人的名称为“用于磁记录的反铁磁性耦合薄膜”美国专利中,用于磁记录的反铁磁性耦合层结构,其中铁磁性顶结构是双层结构,包括与耦合/隔离层接触的铁磁性材料的相对薄的第一子层。该第一子层具有比第二子层更高的磁矩。第二子层的磁矩比第一子层更低,并且比第一子层更厚,并具有选择的组成和厚度,使得当与整个磁性结构必需的第一子层组合时产生Mrt。根据该专利的层结构的优选实施例如下:优选采用CrTi的前籽晶层,优选采用RuAl的籽晶层,优选采用CrTi的底层,优选采用CoCr的铁磁底层,优选采用Ru的反铁磁耦合/隔离层;顶铁磁结构包括:优选采用CoCr、CoCrB或者CoPtCrB材料的较薄第一子层,优选采用CoPtCrB材料的较厚第二子层,其磁矩小于第一子层。
随着磁记录盘的存储密度的提高,剩余磁化强度Mr(铁磁性材料单位体积的磁矩)与磁性层厚度t的乘积降低。同样,磁性层的矫顽磁场或者矫顽力(Hc)提高。这导致Mrt/Hc比的降低。为了实现Mrt的降低,可以降低磁性层的厚度t,但是仅限于因为层将加剧磁性衰减,这起因于小磁性晶粒的热激活,即超顺磁性效应。磁性晶粒的热稳定性在很大程度上取决于KuV,其中Ku是层的磁各向异性常数,V是磁性晶粒的体积。随着层厚度的降低,V也降低。在某一点,随着V的降低,在存储器件的工作条件下,存储的磁性信息将不再稳定。
解决此问题的一种办法是使用各向异性更强的材料,即具有更高Ku的材料。但是,Ku的提高受到矫顽力Hc的限制,矫顽力大致等于Ku/Mr,变得过大将不能由实际的写入磁头来写入。类似的办法是降低用于固定层厚度的磁性层的Mr,但是这也受到能够被写入的矫顽力的限制。另一种办法是提高晶粒间交换,以便增大磁性晶粒的有效磁性体积V。但是,已经表明这种办法对磁性层的本征信噪比(SNR)是有害的。
通过用被非磁性隔离层分隔的两层(或更多)磁性层的磁性叠层,来代替单一的磁性层,能够实现SNR的实质性改善。通过叠层使介质噪声降低确信是由于叠层中的磁性层之间的磁交换耦合的去耦。已经报道包括Cr、CrV、Mo和Ru的厚5到400的隔离层材料,用于实现磁性层的良好去耦合。甚至已经要求了不连续的铬薄膜,用于降低两层磁性层之间的交换耦合。
公开的美国专利申请2002/0098390披露了用于水平磁记录的叠层介质,包括反铁磁性(AF)耦合的磁性层结构和传统的单一磁性层。AF耦合磁性层结构具有的净剩余磁化强度-厚度之积(Mrt)是其两层铁磁性薄膜的Mrt值之差。选取铁磁性薄膜的铁磁性材料类型和厚度值,以使零外加磁场下的净磁矩很小,但是不为零。介质的Mrt由上磁性层的Mrt和AF耦合叠层的Mrt之和确定。
对本申请所用的合金组成约定以下标给出元素的原子百分比,例如,CoCr10是10原子百分比的铬,余量是Co,CoPt11Cr20B7是11原子百分比的铂,20原子百分比的铬、7原子百分比的B,余量是Co。
发明内容
本发明的一个实施例是一种叠层磁记录介质,包括被非磁性隔离层分隔的两磁性层,具有下磁性层,即远离记录磁头的一层,其磁各向异性小于靠近记录磁头的上磁性层的。在本发明的另一实施例中,叠层中的两磁性层之一或者两者可以用反铁磁性(AF)耦合(AFC)层结构代替,该结构具有被隔离层分隔的AFC-主层和AFC从属层,选取该耦合层以便反铁磁性耦合AFC主层和AFC从属层。在具有一个或多个AFC层结构的实施例中,当根据本发明调节各向异性时,AFC从属层可以忽略不计。例如,在下磁性层被AF耦合层结构置换的一个实施例中,调节AFC主磁性层,使其具有比上磁性层低的磁各向异性。由于记录磁头磁场随着与磁头距离的增大而降低,所以根据本发明的磁性层的选取有助于使相关磁性层的磁各向异性与施加于其上的磁头磁场分别匹配。这种匹配可在相同的磁头写入电流下,使磁性层在最佳条件下被磁头写入。根据本发明制成的磁性介质在直流消磁噪声与磁头写入电流的曲线中呈现单一尖锐峰值,这表明在相同的磁头写入电流下写入非从属磁性层中的磁性转变,导致磁记录性能得以改善。与此相比,对上磁性层和AFC主磁性层都使用相同磁性材料的介质,在直流消磁噪声与磁头写入电流的曲线中呈现双峰,表明不利的写入条件,其中两磁性层在不同的磁头写入电流被转换。本发明的优点在于磁性脉冲宽度(PW50)减小,重写(OW)得以改善,介质信噪比(SoNR)得以改善。在一个实施例中,选取上磁性层作为强磁化合金,以便能够使用更薄的层来实现相同的Mrt,并且进一步改善重写。
附图说明
图1是已有技术的示意图,展示了磁盘驱动器中的磁头与相关部件的关系。
图2是用于薄膜磁盘的已有技术层结构的示意图,本发明的磁性叠层可以用于其中。
图3是根据本发明的用于薄膜磁盘的两层磁性叠层的示意图。
图4是根据本发明的用于薄膜磁盘的两层磁性叠层的示意图,其中下磁性层被反铁磁性耦合的磁性叠层置换。
图5是针对根据本发明的磁盘4的归一化直流消磁噪声与磁头写入电流的曲线图,该磁盘具有选取的磁性材料的。
图6是针对已有技术的磁盘的归一化直流消磁噪声与磁头写入电流的曲线图,该磁盘的上磁性层和AFC主磁性层(与磁盘2类似)使用相同的磁性材料。
具体实施方式
图2展示了薄膜磁盘16的公知的层结构,根据本发明的叠层可以用于其中。底层33之下的各层可以是籽晶层32和前籽晶层31的几种任意组合,以下将详细介绍。有用的前籽晶层包括CrTi、CrTiAl、CrTiY,但并不限于此。籽晶层一般用于非金属基片上,但是本发明也可以使用金属基片例如NiP涂敷的AlMg。传统的NiP涂敷的AlMg基片使用Cr、Cr合金、或者Cr和Cr合金的多层的底层结构,这些是直接溅射淀积在NiP上的。本发明并不受限于使用任何特定的底层。
图2所示层结构可以使用各种磁性叠层34。例如,可以使用两层或者多层磁性叠层,反铁磁性耦合层结构可以置换任何或者全部磁性层。磁性叠层34的一个实施例是由图3所示的多层组成的。根据本发明的叠层34的第一实施例是叠层结构,包括上磁性层36(最靠近磁盘表面、从而最靠近磁头的磁性层)、隔离层37和下磁性层38。下磁性层38的材料选取具有比上磁性层36低的磁各向异性。主要通过改变钴基磁性合金、例如CoPtCr、CoPtCrTa或者CoPtCrB中铂的原子百分比,可以调节磁各向异性。铂的原子百分比高可以产生高的磁各向异性。铬和硼的含量也可以影响磁性材料的磁各向异性。通常,低的铬和/或硼含量导致高的磁各向异性。虽然不是必需的,但优选使用具有高磁化强度的材料作为上磁性层,以便以小的厚度实现相同的Mrt,从而进一步改善OW。通过改变铬和/或硼的原子百分比,可以调节磁化强度。例如,减少铬和/或硼含量,增加钴含量,可以提高磁化强度。
磁性叠层34的第二实施例如图4所示。如上所述,反铁磁性耦合层结构可以置换叠层中的任何或者全部磁性层。图4的实施例具有反铁磁性耦合层结构41,代替了图3的下磁性层38。根据本发明的反铁磁性耦合层结构41具有至少三个不同的层,通过非磁性隔离层与磁性层进行反铁磁性耦合。反铁磁性耦合层结构41的两磁性层中,上一层将称为AFC主磁性层42,下一层将称为AFC从属磁性层44。这些层中的每一个都是已有技术的薄膜磁盘中所使用类型的铁磁性材料。适用的材料例子包括CoCr、CoCrB、CoCrTa、CoPtCr、CoPtCrTa和CoPtCrB。AFC从属磁性层44的厚度必须选取得使其Mrt低于AFC主磁性层42的Mrt。AFC隔离层43是非磁性材料,其厚度选取得使AFC主磁性层42和AFC从属磁性层44能够反铁磁性耦合。耦合/隔离层43的优选材料是钌,但是已有技术表明适当的材料包括铬(Cr)、铑(Rh)、铱(Ir)、铜(Cu)及其合金。AFC隔离层43的厚度是根据已有技术的,例如,对于铑AFC隔离层43而言,优选的靶厚度是6埃左右。根据本发明的上磁性层36是磁各向异性比AFC主磁性层42更高的铁磁性材料。随着与磁头的距离的增大,记录磁头磁场降低。因此,在给定的磁头写入电流,施加在AFC主磁性层上的磁头磁场比施加在上磁性层上的磁场要弱。因此,为了使相关磁性层的磁各向异性与施加其上的磁头磁场分别匹配,AFC主磁性层具有的磁各向异性必须比上磁性层的低。该两磁性层的磁各向异性之差取决于磁头磁场随距离而降低的特性。上磁性层也应具有高的磁化强度。
在另一可选实施例中,可以用AF耦合层结构41置换上磁性层36。用于该实施例的各层与图4所示的相同,只是AF耦合层结构位于顶部。在此可选实施例中,下磁性层38具有比AFC主磁性层42低的磁各向异性。AFC主磁性层最好具有高的磁化强度。
在又一可选实施例中,上磁性层36和下磁性层38分别被两个AF耦合层结构41置换。在此可选实施例中,AF耦合层结构中置换下磁性层38的AFC耦合主磁性层具有的磁各向异性,低于AF耦合层结构中置换上磁性层36的AFC耦合主磁性层的。AF耦合层结构中置换下磁性层38的AFC耦合主磁性层最好具有高的磁化强度。
表1-5对比了九个实验磁盘,每次两个,抽出单个性能的变化所导致的差异。介质结构如图2和4所示。每层的材料如该表的标题或者正文对每个测试磁盘所示的。KuV/kT值是对制成的介质而言的。每个磁盘具有CrTi50的前籽晶层和RuAl50的籽晶层。表1对比了两个磁盘,其中反铁磁性耦合的磁性叠层34中的AFC主磁性层42的合金不同,如图4所示。磁盘1具有AFC主磁性层,其磁各向异性(CoPt11Cr20B7)低于上磁性层(CoPt12Cr14B11)的。磁盘2中的AFC主磁性层和上磁性层由相同的材料(CoPt12Cr14B11)制成。调节磁盘1中的AFC主磁性层的厚度,以使磁盘1具有与磁盘2类似的热稳定性,如它们的KuV/kT值所示(磁盘1=73;磁盘2=74)。两个磁盘具有类似的热稳定性这一事实表明,通过牺牲热稳定性并未使磁盘1的记录性能比磁盘有所改善。结果表明磁盘1在OW方面比磁盘2改善是提高了3.5dB,在更高幅度下PW50降低了3.9nm,SoNR提高了0.9dB。
表1
CrTi50/RuAl50/底层/CoCr10/Ru/AFC主磁性层/Ru/CoPt12Cr14B11
AFC主磁性层 | Hc(Oe) | M<sub>r</sub>t(memu/cm<sup>2</sup>) | S<sub>o</sub>NR | OW(dB) | PW<sub>50</sub>(nm) | LFTAA(mv) | KuV/kT | |
磁盘1 | CoPt<sub>11</sub>Cr<sub>20</sub>B<sub>7</sub> | 3762 | 0.65 | 31.0 | 25.4 | 123.4 | 1.560 | 73 |
磁盘2 | CoPt<sub>12</sub>Cr<sub>14</sub>B<sub>11</sub> | 3998 | 0.69 | 30.1 | 21.9 | 127.3 | 1.362 | 74 |
表2中的数据对比了磁盘1和磁盘3。磁盘3具有其磁化强度比磁盘1高的上磁性层,但是其余相同。磁盘3具有比磁盘1高0.4dB的OW,其热稳定性KuV/kT等于76,同样高于磁盘1(KuV/kT=73)。磁盘1-3都具有CrTi10的底层。磁盘4-7的底层使用CrTi20,这有助于大幅度降低PW50。
表3展示了申请人发现将AFC主磁性层减薄到一定程度,可以改善叠层AFC耦合介质的OW,而不明显影响热稳定性。表3对比了AFC主磁性层的厚度不同、从而Mrt也不同的磁盘4和6。AFC主磁性层较薄的磁盘6的OW比磁盘4高1.2dB,而KuV/kT仅降低一个单位。
表2
CrTi50/RuAl50/底层/CoCr10/Ru/CoPt11Cr20B7/Ru/上磁性层
上磁性层 | Hc(Oe) | M<sub>r</sub>t(memu/cm<sup>2</sup>) | S<sub>o</sub>NR | OW(dB) | PW<sub>50</sub>(nm) | LFTAA(mv) | KuV/kT | |
磁盘3 | CoPt<sub>12</sub>Cr<sub>16</sub>B<sub>9</sub> | 3850 | 0.65 | 30.9 | 25.8 | 124.2 | 1.566 | 76 |
磁盘1 | CoPt<sub>12</sub>Cr<sub>14</sub>B<sub>11</sub> | 3762 | 0.65 | 31.0 | 25.4 | 123.4 | 1.560 | 73 |
表3
CrTi50/RuAl50/CrTi20/CoCr10/Ru/CoPt11Cr20B7(Mrt变化)/Ru/CoPt12Cr16B9
M<sub>r</sub>t(memu/cm<sup>2</sup>)AFC主磁性层 | Hc(Oe) | M<sub>r</sub>t(memu/cm<sup>2</sup>) | S<sub>o</sub>NR | OW(dB) | PW<sub>50</sub>(nm) | LFTAA(mv) | KuV/kT | |
磁盘6 | 0.34 | 3594 | 0.64 | 26.3 | 25.7 | 125.6 | 1.884 | 75 |
磁盘4 | 0.38 | 3674 | 0.67 | 26.2 | 24.5 | 127.8 | 1.982 | 76 |
表4
CrTi50/RuAl50/CrTi20/CoCr10/Ru/CoPt11Cr20B7/Ru/上磁性层
上磁性层 | Hc(Oe) | M<sub>r</sub>t(memu/cm<sup>2</sup>) | AC挤压(Squeeze) | S<sub>o</sub>NR | OW(dB) | PW<sub>50</sub>(nm) | LFTAA(mV) | KuV/kT | |
磁盘7 | CoPt<sub>13</sub>Cr<sub>19</sub>B<sub>7</sub> | 3736 | 0.58 | 53.8 | 26.9 | 25.5 | 119.2 | 1.476 | 75 |
磁盘6 | CoPt<sub>12</sub>Cr<sub>16</sub>B<sub>9</sub> | 3594 | 0.64 | 48.4 | 26.5 | 25.5 | 120.4 | 1.606 | 75 |
表4对比了磁盘6和磁盘7,展示了提高上磁性层的各向异性,降低了边频带消磁。采用较高各向异性的上磁性层(CoPt13Cr19B7)的磁盘7具有较高的AC挤压(squeeze),导致边消磁频带宽度的减小。由于Mrt和Hc的变化,磁盘7的热稳定性和OW保持在与磁盘6相同的水平。
通过在上磁性层和AFC主磁性层之间使用较薄的Ru上隔离层41,可以进一步改善根据本发明的叠层AF耦合的磁盘结构的OW。表5和6展示了当上隔离层厚度从1.2nm(磁盘9)降低到0.8nm(磁盘8)时,OW提高1dB。
表5
CrTi50/RuAl50/CrTi20/CoCr10/Ru/CoPt11Cr20B7/Ru(厚度变化)/CoPt13Cr19B7
Ru厚度(nm) | Hc(Oe) | M<sub>r</sub>t(memu/cm<sup>2</sup>) | S<sub>o</sub>NR | OW(dB) | PW<sub>50</sub>(nm) | LFTAA(mv) | |
磁盘8 | 0.8 | 3694 | 0.58 | 27.7 | 23.7 | 118.6 | 1.476 |
磁盘9 | 1.2 | 3712 | 0.58 | 27.5 | 22.7 | 118.3 | 1.606 |
表6
CrTi50/RuAl50/CrTi20/CoCr10/Ru/CoPt11Cr20B7/Ru(厚度变化)/CoPt12Cr20B6
Ru厚度(nm) | OW(dB) |
0.6 | 28.1 |
0.8 | 28.1 |
1.0 | 27.5 |
1.2 | 27.1 |
正如在先已经讨论过的,根据本发明磁盘4选取具有不同磁各向异性的磁性材料,以使相关的磁性层的磁各向异性分别与施加其上的磁场匹配。结果,在归一化直流消磁噪声与磁头写入电流曲线中观察到单一的尖锐峰值(图5),这表明上磁性层和AFC主磁性层的磁转换都出发生相同的磁头写入电流,以致提高了磁记录性能。与此相比,上磁性层和AFC主磁性层都使用相同磁性材料的已有技术的磁盘(类似于磁盘2),在归一化直流消磁噪声与磁头写入电流曲线中呈现双峰值(图6),这表明两磁性层在不同的磁头写入电流下进行转换的不利写入条件。这种测量可以用于调节磁各向异性。例如,图6曲线中的较小磁头写入电流处的峰值对应于最靠近磁头的磁性层、即上磁性层的转换点。因此,为使下磁性层即AFC主磁性层的转换更与上磁性层一致,AFC主磁性层的磁各向异性应降低,以便可使其在较小的磁头写入电流转换。采用直流消磁噪声的调谐是实用的技术,但是也可以使用如上所述的实际的记录性能测量。
可以采用标准的溅射技术来形成上述的薄膜结构。依次溅射淀积这些薄膜,每个薄膜淀积在前一薄膜上。以上给出的原子百分比组成未顾及溅射薄膜中不可避免地存在的少量杂质,这对于本领域技术人员来说是显而易见的。
参照具体实施例已对本发明进行了说明,但是对于本领域技术人员来说,根据本发明的铁磁性结构的其它利用和应用也是显而易见的。
Claims (5)
1.一种薄膜磁记录介质,与磁记录头一起使用,包括:
第一反铁磁性耦合磁层结构,具有第一反铁磁性耦合主铁磁性层和第一反铁磁性耦合从属铁磁性层,它们通过第一隔离层形成反铁磁性耦合,所述第一反铁磁性耦合主铁磁性层具有第一磁各向异性;
第二隔离层,与第一反铁磁性耦合从属铁磁性层相邻;和
第二反铁磁性耦合磁层结构,设置在第一反铁磁性耦合磁层结构和第二隔离层之下,具有第二反铁磁性耦合主铁磁性层和第二反铁磁性耦合从属铁磁性层,它们通过第三隔离层形成反铁磁性耦合,第二反铁磁性耦合主铁磁性层具有比第一磁各向异性低的第二磁各向异性,选取该降低量,以便对因磁记录头与第二反铁磁性耦合主铁磁性层之间距离大而导致的、来自磁记录头的弱磁场进行补偿,第二反铁磁性耦合磁层结构被设置成使得第二隔离层将第二反铁磁性耦合主铁磁性层与第一反铁磁性耦合从属铁磁性层分隔开,
其中,第一和第二反铁磁性耦合主铁磁性层包括钴和铂,第二反铁磁性耦合主铁磁性层具有的铂原子百分比要比第一反铁磁性耦合主铁磁性层的低。
2.根据权利要求1的薄膜磁记录介质,其中,响应磁记录头中的第一写入电流幅度所产生的第一磁场,第一反铁磁性耦合主铁磁性层发生转换,响应磁记录头中的第二写入电流幅度所产生的第二磁场,第二反铁磁性耦合主铁磁性层发生转换,所述第一和第二写入电流幅度相等。
3.根据权利要求1的薄膜磁记录介质,其中,磁记录头中的归一化直流消磁噪声相对写入电流的曲线具有单一峰值。
4.根据权利要求1的薄膜磁记录介质,其中,第一和第二反铁磁性耦合主铁磁性层包括钴、铂、铬和硼,第二反铁磁性耦合主铁磁性层具有的铂原子百分比要比第一反铁磁性耦合主铁磁性层的低。
5.根据权利要求1的薄膜磁记录介质,其中,第一反铁磁性耦合主铁磁性层具有的磁化强度高于第二反铁磁性耦合主铁磁性层的磁化强度。
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DE602004006343D1 (de) | 2007-06-21 |
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US20050019609A1 (en) | 2005-01-27 |
JP2005056551A (ja) | 2005-03-03 |
DE602004006343T2 (de) | 2008-01-10 |
CN1577507A (zh) | 2005-02-09 |
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