超高密度磁记录介质的研究进展

总结了近年来超高密度磁记录介质的研究概况,着重介绍了垂直磁记录介质中L10相FePt薄膜的研究方法,并认为L10相FePt薄膜将会成为高密度磁盘记录介质的主流.倾斜磁记录、热辅助磁记录、图案记录等存储技术,目前处于实验室研究阶段,但是有望突破垂直磁记录的超顺磁极限,实现超高密度磁记录.     

大容量盒式软磁盘试制成功

日本东京芝浦电气公司最近宣布,试制成功垂直磁记录方式的小型大容量盒式软磁盘,同时试制了与之配套的读取和存储装置。该公司在规格统一等方面尚需花一段时间,计划两年后可批量生产。垂直磁记录是相对于记录介质面进行垂直方向记录信息的新方法,与通常的平行记录方式相比,有可能大幅度提高记录密度。一九七五年日本东北大学岩崎俊一教授首先     

超高密度磁记录介质的研究进展与未来趋势

磁记录在过去的50年内经历了磁带、硬盘水平记录模式和垂直记录模式,其记录面密度达到～150Gbit/in~2,50年中记录面密度提高了约10~7倍。在未来5～10年内,磁记录面密度的目标是1000Gbit/in~2(即今天的6～7倍)。本演讲将从磁记录介质因素(磁晶各向异性能和磁有序诱发相分离)和记录模式两方面来评述磁记录面密度的发展过程和相关科学问题的解决、现在面,临的“瓶颈“困境以及未来的发展方向。首先从热力学的角度综述了最近几年对当前唯一可行的Co-Cr基合金介质发生的这种磁有序诱发相分离的认识和理解,通过实验证据和热力学计算来阐明该合金体系能形成纳米双相组织的成因,并解释有效合金化元素Pt、Ta、B对Co-Cr基合金薄膜提高其有效磁晶各向异性能和降低记录噪音的作用。详细分析该体系多元合金作为磁记录介质发展过程中的科学问题(磁晶各向异性能的改善、磁记录信噪比(SNR)的提高与双相组织的关系)以及目前面临的困境(超顺磁)和可能解决的方案。着重阐明未来可能的超高密度记录材料(相分离型合金Co-W和Co-Mo、有序化型合金CoPt和FePt,稀土型合金FeNdB和SmCo_5等)的研究进展和以上各种材料目前存...     

磁记录和磁光记录材料及其发展

本文介绍了磁记录和磁光记录方式及其原理,磁记录及磁光记录材料的特性、制法和应用,以及在当代信息社会的重要作用和发展前景。     

光辅助磁记录-混合记录技术研究进展

混合记录又称为光辅助磁记录，是近年来发展起来的超大容量存储技术，它以激光辅助热磁记录和磁通检测读出为主要特征，具有记录密度潜力大、读出灵敏度和分辨高等优点，是一种很有前途的记录方式。本文较全面地介绍了这种记录方式的基本原理、记录介质及其研究现状，并讨论了其发展前景。     

超高密度图案化磁信息存储介质的研究进展

信息存储的容量不断增大才能满足信息社会高速发展的需求。要提高磁信息存储的容量,就必须不断减小用于记录数据信息位的磁性颗粒的尺寸,但当尺寸减小到一定程度时,由于超顺磁效应将影响磁信息信息位的稳定性,所以必须开发新型高密度磁记录技术。目前,商用硬盘的磁记录技术正从传统的水平记录技术向垂直记录技术过渡,但正如业内人士指出那样,为了应对其它超高密度存储技术,如有机存储、光存储等的挑战,垂直记录技术只是磁信息存储技术向超高密度方向发展的一个“跳板“。展望2011年前后的新技术,希捷提出了“热辅助磁性写入“(heat-assisted magnetic recording)技术,该技术的实质是采用高矫顽力的磁性材料如铁铂合金作为记录介质,在信息写入时通过激光束加热降低信息位翻转场写入信息。而日立存储则提出“图案化介质“(patterned media)技术,在这种技术中,存储数据的信息位宛如“点“一样彼此相互独立,减少相互间的干扰和降低数据信息位损坏的危险。这两种技术都可望将磁信息存储密度提高到1Tbit/平方英寸以上,但是它们的实用化还有许多科学与工程问题需要解决。详细介绍了图案化介质记录技术的工作原理、读写存储系统的...     

Ag底层对TbFeCo薄膜磁性能的影响

采用射频磁控溅射法在玻璃基片上制备了TbFeCo/Ag非晶垂直磁化膜，研究了Ag底层厚度对TbFeCo薄膜磁性能的影响。原子力显微镜、振动样品磁强计与磁光盘测试仪测量结果表明：薄的银底层具有较高的表面粗糙度可以显著增大TbFeCo薄膜的矫顽力，改善TbFeCo薄膜的磁光温度特性，该薄膜有望用作高密度垂直记录介质与光磁混合记录介质。     

光磁混合记录技术及材料进展

光磁混合记录技术是一种将磁光记录及磁记录的优点相结合,获得极高存储密度的新型数据记录方式.文中较全面地介绍了这种记录方式的基本原理、读写方式、记录介质及记录磁头研究现状,展望了这种记录方式的前景,探讨了目前所面临的问题.     

CoCr基磁性薄膜材料的研究现状和发展趋势

简要介绍了磁记录用介质膜的发展趋势及面临的问题,介绍了垂直记录方式的优点,综述了国内外对垂直磁记录用介质膜材料的分类及研究现状,回顾和评述了CoCr基磁性薄膜的研究现状和发展趋势.     

磁记录技术的发展

磁记录技术是一种利用磁性物质作记录、存储和再生信息的技术,它包括录音、录象以及数字信息存储。磁记录材料有磁卡、磁鼓、磁带、磁盘和磁泡等,目前用途最广、用量最大的是磁带。近年来随着电磁物理学和电子应用技术的发展,新型磁记录材料和记录技术不断涌现,有关磁盘和磁     

Perpendicular magnetic recording -- Evolution and future

This paper reviews research results for the head, medium and recording properties of a perpendicular recording system. Superior bit density characteristics obtained so far indicate that perpendicular recording is basically free from demagnetization in the high density region and that it will establish a new field of recording technology in the future. The prediction is explained in the context of complementary profiles of longitudinal and perpendicular recording. At the very beginning of magnetic recording, a perpendicular-type head was considered but abandoned because a suitable medium did not exist. Progress in material science has enabled us to develop a perpendicular recording medium which is very well suited for ultra high density recording. As so often happens, history has repeated itself through another study of perpendicular recording.     

Properties, preparation, advances and limitations of materials andmedia for perpendicular recording

The trends in perpendicular magnetic recording research are discussed, with emphasis on clarifying the trend of research on recording media, their materials, and head materials. Among numerous proposed perpendicular recording media materials, barium ferrite powder and evaporated Co-Cr films seem to lead in practical applications, since their mass production seems to be very successful. There still exist crucial points in their development. However, improvements are continuously taking place. Other candidate perpendicular recording media for a device which has a ring head are also discussed. It is concluded that, for future high-density magnetic recording, utilizing fully the perpendicular component of media magnetization will furnish the key to success     

Perpendicular magnetic recording

This paper describes the recent studies for the magnetic head, the medium and the recording properties on a new perpendicular magnetic recording system. The complemental features between the perpendicular and the longitudinal recording are discussed to establish an efficient magnetic recording system. Superior response in the amplitude and the peak shift characteristics for a digital signal proves that the perpendicular magnetization mode is basically free from the recording demagnetization in high densities and the maximum density has been limited merely by the resolution of the reproducing head. Significant improvement for the recording and the reproducing sensitivities of a perpendicular head has been made by using a composite anisotropy medium composed by double layers of Fe-Ni and Co-Cr thin films.     

L10 ordered FePt based double-layered perpendicular recording media with (002) oriented FeCo films as a soft magnetic underlayer

The introduction of the soft magnetic underlayer (SUL) in perpendicular recording technology is to further increase the recording areal density. However, problems such as growth of the uncontrollable recording layer and additional media noise contributed from the SUL could be resulted. In this work, a synthetic antiferromagnetically (SAF) coupled (002) oriented Fe₆₅Co₃₅ film as an SUL was developed for L1₀ ordered FePt based double-layered recording media. The crystallography of hetero-epitaxially grown double-layered media CrRu/(Ru/FeCo)₂/Pt/FePt/Ru was demonstrated. The L1₀ ordered FePt based double-layered perpendicular recording media with SAF coupled FeCo films as the SUL were developed.     

溅射工艺条件对TbFeCo/Pt薄膜磁性能的影响

采用射频磁控溅射法在玻璃基片上成功制得了TbFeCo/Pt非晶垂直磁化膜,系统研究了溅射工艺参数对TbFeCo薄膜磁性能的影响.振动样品磁强计测量结果表明:Tb含量在补偿成分点附近,采用较低的溅射氩气压与Pt底层,有利于提高TbFeCo薄膜的磁性能;当Tb含量为0.24,溅射功率为300W,溅射气压为0.53Pa,薄膜厚度为140nm时,TbFeCo/Pt薄膜矫顽力达到476kA/m,饱和磁化强度为151kA/m,剩磁矩形比超过0.8,该薄膜有望用作高密度光磁混合记录介质.     

Recording characteristics of electroless-plated perpendicularrecording flexible disks with a perpendicular head

Perpendicular magnetic recording using a main-pole-driven perpendicular head was tested using electroless-plated flexible disks. Soft magnetic NiFeP films, also produced by electroless plating, were used as an underlayer of a perpendicular recording medium in this test. Two types of flexible double-layer media, composed of an electrodeless-plated CoNiReP film with two types of NiFeP underlayers with a coercivity of 2 and 5.5 Oe, were fabricated, and their recording characteristics were measured. A recording density value of 75 kFRPI was obtained for the medium with the softer magnetic 2-Oe underlayer, about twice as high a value as that for the medium with the 5.5-Oe underlayer     

Magnetic recording configuration for densities beyond 1 Tb/in/sup 2/ and data rates beyond 1 Gb/s

A new magnetic recording system is evaluated that includes the single-pole head, a new medium design, and the soft underlayer of perpendicular recording. The proposed medium consists of perpendicular grains with anisotropy directions tilted optimally about 45/spl deg/ with respect to the perpendicular direction. Here, focus is on the tilt angle at 45/spl deg/ in the crosstrack direction, including a small but typical dispersion. The write pole consists of a tapered-neck single-pole head with a very small throat height that yields maximized write fields without increased edge track degradation. The advantages of tilted perpendicular recording are discussed using theoretical and numerical micromagnetic analyses. This design achieves a much higher signal-to-noise ratio (SNR) than conventional recording, because it is less sensitive to medium orientation distributions and, for the same thermal decay, can utilize media with much smaller grain sizes. The switching speed is much more rapid due to increased recording torque. Estimated recording limits for tilted perpendicular recording with a medium-jitter SNR of 17 dB are beyond densities of 1 Tb/in/sup 2/ and data rates of 1 Gb/s.     

Recording on perpendicular anisotropy media with ring heads

This paper reports experimental studies directed at the application of ring head structures to a perpendicular recording system. The media tested were sputter deposited films of CoCrTa alloys. Ferrite heads were studied, but the thin film head was chosen for evaluating roll-off, overwrite, and superposition. The data presented in the paper demonstrates the potential of high density recording with a single layer medium with perpendicular magnetic anistropy and a thin film head separated by 0.20 micrometers.     

Magnetic properties of thin films prepared by continuous vapor deposition

Magnetic thin films deposited by the oblique incidence evaporation are considered to have excellent characteristics for high density recording medium. The magnetic properties and microstructures of these films prepared continuously with a roll coater have been investigated. In continuous vapor deposition, two different modes of deposition processes are considered, corresponding to substrate running direction. The HIN (high incidence nucleation) direction implies that deposition initiates at higher incidence angle and shifts to lower incidence angle. The LIN (low incidence nucleation) direction is the opposite. Hc and Ir/Is of the films by HIN direction have larger values than those by LIN direction in the same region of incidence angle. According to TEM micrographs of thin films by HIN direction, it is observed that elongated nucleation is taken place in higher incidence angle direction and subsequently grown in same direction.