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Article type: Cover
Pages Cover1-
Published: November 08, 2001
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSDownload PDF (14K) -
Article type: Index
Pages Toc1-
Published: November 08, 2001
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSDownload PDF (90K) -
Yoshihisa NAKAMURAArticle type: Article
Session ID: MMS2001-85
Published: November 08, 2001
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSIn recent years, perpendicular magnetic recording have progressed rapidly. So it will not be long before perpendicular magnetic recording is put into practical use. However there have been few tools contributing to optimum design of perpendicular magnetic recording media and heads except for computer simulations. Based on the concept of self-consistent magnetization, the authors have introduced a simple method to predict analytically main parameters for recording media and writing heads to realize high bit density recording. In this paper, main parameters to realize high bit density recording over 100kbit/inch^2 is discussed first through this method, and then the current status and the future problems in perpendicular magnetic recording technology are described.View full abstractDownload PDF (762K) -
Kiyoshi Yamakawa, Kazuyuki Ise, Shingo Takahashi, Kazuhiro OuchiArticle type: Article
Session ID: MMS200l-86
Published: November 08, 2001
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSA new single-pole-type head with a novel structure has been developed. The coil windings of the head are located on both side of the main pole and produces cusped magnetic field to energize the main pole. Overlaying the main pole and the coil, two layer of return path yokes are formed. Head field calculation was perfomed to design the head for in terms of high writabilily. It was found that the head generates preferable field distribution showing little field at the trailinmg return yoke. The field strength and the gradient can be improved by reducing throat heigh of the main pole and narrowing the separation between the main pole and the return yoke, respectively. This was supported by the recording measurements with fabricated heads and double layer media. The new head also provides high stray field immunity due to a shielding effct of the returm yokes. Furthemore, main-pole design which enable to produce extremery high field has been proposed. Furthermore, main-pole design which enable to produce extremery high field has been proposed.View full abstractDownload PDF (943K) -
Sam Shueh, Liu LuArticle type: Article
Session ID: MMS200l-87
Published: November 08, 2001
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSModern GMR reader sensors exhibit magnetic instabilities phenomena. Signatures from read back signals and amplitude spikes can cause sudden magnetic signal fluctuation. In this paper, we studied bottom spin valve heads capable of storing from 40 Gigabyte or more of data on a single 95 mm platter. A systematic study was conducted to investigate diffrent types of instabilities as they affect magnetic signal amplitudes and asymmetries. We have the discriminating power to confirm if the instability was externally induced, or intrinsic to the GMR sensor. By switching write current on and off and sandwiching it between turning bias voltage on and off we were able to understand the mechanism of each mode. A simplistic but well understood(COR) techique was developed to correctly identify the causing mechanism.View full abstractDownload PDF (491K) -
E.Z. Luo, S.K. Wong, A.B. Pakhomov, B. Sundaravel, J.B. Xu, I.H. Wilso ...Article type: Article
Session ID: MMS200l-88
Published: November 08, 2001
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSIn this article, we present a study to measure average thickness and as well as the thickness uniformity of the ultra-thin AlO_x barrier layer by combined RBS and conducting atomic force microscopy(C-AFM). RBS in tilted angle geometry was used to determine the average thickness on a macroscopic scale. By carefully analyzing the variation of energy width of Al spectra with tilt angle, the average thickness of AlO_x layers has been quantitatively determined. The thickness and thickness uniformity on a microscopic scale was measured by C-AFM. The errors of both techniques will also be discussed.View full abstractDownload PDF (461K) -
Byongguk Park, Taek Dong LeeArticle type: Article
Session ID: MMS200l-89
Published: November 08, 2001
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSMagnetic tunnel junctions with Al_2O_3 barrier layer oxidized by ozone and oxygen mixture gas(ozone atmosphere) were fabricated and Al oxidation characteristics were investigated. The TMR ratio and junction resistance of ozone oxidized junctions were 33% and several KΩμm^2 at the junction area of l0×l0μm^2. In this study, oxidation kinetics and its chemistry were investigated using transmission electron microscopy(TEM) and X-ray photoelectron spectroscopy(XPS). To study the growth characteristics of Al oxide in ozone atmosphere, the Al layers were oxidized under zero, positive and negative bias conditions. Both positive and negative bias accelerated aluminum oxidation, O/Al ratio was not uniform through the oxide layer grown under positive bias condition.View full abstractDownload PDF (737K) -
Xuan Zhang, Dan WeiArticle type: Article
Session ID: MMS200l-90
Published: November 08, 2001
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSA simplified model is set up to study the high frequency response in a thin film head, where two pieces of Fe-Al-N films are placed parallel to each other with opposite alternating external magnetic field applied. ln this model, the frequency response of magnetization vectors in clusters is solved by the Landau-Lifshitz-Gilbert equations, and the permeability of mesoscopic Fe-Al-N thin films analyzed in a wide frequcncy region from 10 to 5000MHz. The model of a soft magnetic thin film is built up based on the ripple structure of the anisotropy field. The magnetostatic interaction between the two Fe-Al-N films is carefully computed to find its effects on the frequency response. The frequency response in a single mesoscopic Fe-Al-N thin film is carefully studied in advance.View full abstractDownload PDF (409K) -
Tian Xie, Yungui Ma, Xiaohong Li, Xiaohui Wei, Fulin Wei, Zheng YangArticle type: Article
Session ID: MMS200l-91
Published: November 08, 2001
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSThe nanocrystalline soft magnetic FeAlN films have been successfully prepared by RF reactive sputtering. The dependences of structure and magnetic properties on preparing conditions were investigated. The results show that the content of Al in films must be strictly controlled to attan high B_s. The magnetic properties strongly depend on the temperature of the substrate during deposition and good soft magnetic properties can be found in the films sputterd at T_s=120℃. With the increase of film thickness, the saturation magnetization M_s increases, In contrast to M_s the coercivity H_c decreases. In this paper the relations between magnetic changes and microstructure have been discussed.View full abstractDownload PDF (395K) -
E. Lie, B. Liu, B. Blanpain, J.-P. Celis, D.Q. XuArticle type: Article
Session ID: MMS200l-92
Published: November 08, 2001
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSThe coefficient of friction has generally been defined as the ratio of friction force to applied normal force. When the friction is measured with scanning force microscopy, both the cantilever normal bending force and the adhesive force between cantilever tip and sample surface may influence the level of friction. Additionally, systematic errors may be induced by equipment related sources. In order to elucidate these effects, a number of systematic experimental tests were performed and analyzed. It is shown that proper attention to the experimental procedure is required for a meaningful characterization of the tribological behavior of materials at nanoscale.View full abstractDownload PDF (360K) -
Jiaping Yang, Shixin Chen, Zhejie Liu, Qide ZhangArticle type: Article
Session ID: MMS200l-93
Published: November 08, 2001
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSWith areal recording density of hard disk drives(HDD) historically growing at an average of 60-l00 % annually, it is becoming increasingly more difficult to maintain the precise positioning required of the ever-smaller GMR heads to read and write data. Any unexpeced vibration will cause the data writte to a wrong data track Consequently, the dynamic behaviors of HDD spindle systems and their potential influences on track misregistration are always key issues in disk drive design. This paper studies dynamic performance of HDD spindle systems using a computer simulation approach, which uses the combined multi-body system technology and finite element based component mode synthesis method. The elastic component natural frequencies and modal shape vectors are obtained using a finite element analysis. Their modal shape vectors are then incorporated into the goveming equations of motion for HDD spindle systems. An implicit numerical integration method is used to solve the dynamic equations. Two typical HDD spindle systems were investigated numerically and verified experimentally.View full abstractDownload PDF (560K) -
Wei HUA, Ni SHENG, Bo LIUArticle type: Article
Session ID: MMS200l-94
Published: November 08, 2001
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSLoad/unload techniques are widely used in mobile hard disk drives which have to endure external shocks frequently. ABS designs must consider both the load/unload perfomance and the shock resistance perfomance. Three ABS designs with different positions of suction force center, are studied in simulation. It is observed that when the position of suction of force center moves frontward, the anti-shock performance improves, but the unload performance degrades, and vice versa. A slider is not necessary to be designed to have its suction force center significantly behind of its geometric center, as the taditional load/unload sliders do. Instead, the suction force center can be designed near the geometric center if the hook limiter is used.View full abstractDownload PDF (506K) -
Sheng-Bin Hu, Zhi-Min Yuan, Wei Zhang, Bo Liu, Lei Wan, Rui XianArticle type: Article
Session ID: MMS200l-95
Published: November 08, 2001
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSThe interaction between slider, lubricant and disk surface is becoming the most crucial robustness concern of advanced data storage systems. This paper reports comparative studies among various techniques for the measurement of head-disk spacing. It is noticed that the triple harmonic method gives a reading much closer to the reading of the head-disk spacing obtained optically at on-track center case, comparing with the PW50 method. Specially prepared disks with different carbon overcoat thickness(6.5nm, 11nm, 16nm and 22nm) were also used to study the reliability and repeatability of the triple harmonic method.View full abstractDownload PDF (550K) -
Bo Liu, Yijun Man, Wei Zhang, Yansheng MaArticle type: Article
Session ID: MMS200l-96
Published: November 08, 2001
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSAs technology moves to sub-l0 nm grain size for magnetic disk media and sub-10 nm or deep sub-l0 nm head-disk spacing, it is of crucial importance to prevent the conventionally defined thermal decay and tribologically induced decay of recorded magnetic signal. A novel method is proposed by the authors to record and, then, visualize the signature of potential tribological decay. The details of the methodology, its working principles, and typical results obtained are presented in this work. The method is based on a special disk which uses a layer of magneto-optical material with low Curie temperature to replace the magnetic layer used in magnetic media. The method and corresponding setup were used successfully in the visualization of potential decay caused by slider-particle-disk interaction, slider-disk interaction during track seeking operations, and slider-disk impact during loading and unloading operations.View full abstractDownload PDF (1224K) -
Sam Shueh, Zhi Yun LiArticle type: Article
Session ID: MMS200l-97
Published: November 08, 2001
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSThe magnetic particles of the head and media are known to degrade the performance of the disk drive. Through decades of ongoing improvements of the level of magnetic contamination, although detectable, is low in today's Hard Disk Drives(abbre.HDDs.Yet, exposure to aggressive environments like flying heigh, thinner films, and very high storage density can still cause tribological as well as magnetic erasures issues leading to poor performance on Error Rates leading to the uncorrectable hard errors on the hard media. There is great interest to control the size and particles in the HDD components. But there isn't a lot of data from the published papers on the subject especially those employing Giant Magneto-Resistive Recording Head Technology. In this paper, we studied the effect of the performace parameters from the magnetic contaminants. By collecting mgnetic particles sources from hard disk drive assembly areas on witness plates, we identified the type and size. By doping the wanted magnetic particles on the sliders and fly them, put these heads on the test spin stands, then finally introduce the particles into HDDs we attempt to study the effect of wear at Head disk inteface, as well as the magnetic parameters as it affects real performance of the HDD.View full abstractDownload PDF (795K) -
Yi Lu Shixin, Qinghua LiArticle type: Article
Session ID: MMS200l-98
Published: November 08, 2001
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSThe recording density of magnetic hard disc drives(HDD) has been increasing with astonishing speed. The technical leap which allows much narrower data track width is expected. This requires high bandwidth servo position control of the read/write(R/W) head because the head must follow the narrow data track with high accuracy. A slider driven device, which including a pair of moonie piezoelectric(PZT) microactuators and a frame holder, is invented to achieve more accurate positioning of the magnet head and to increase the servo bandwidth. The moonie PZT microactuator is designed to amplify the actuating displacement. The stroke of displacement is about ±0.5 μm with a drive voltage of ±20V. The dynamic performances of the PZT microactuator are evaluated by finite element method(FEM). Comparing to the I-shape PZT microactuator[l], the shock resistance of the moonie PZT Microactuator is much better.View full abstractDownload PDF (967K) -
Terumitsu Tanaka, Toshiyuki SuzukiArticle type: Article
Session ID: MMS200l-99
Published: November 08, 2001
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSActivation volume and inter-particle interaction were evaluated using super-fine Ba ferrite particle coated media, which were oriented or non-oriented. It was clarified that a peak value of ΔM plot, which was used for evaluation of inter-particle interaction, differs according to the degree of media orientation. The activation volumes of super fine particulate media were found to be 2 times as much as their physical volumes. This suggested that more than 2 particles are stacked and act together in magnetization reversal. An effective value of K_uV_<ac>/kT was also estimated. For media composed of super-fine Ba ferrite particles with diameter of about 22nm, K_uV_<ac>/kT vaIues were close to the critical value in thermal stability.View full abstractDownload PDF (428K) -
Dong Hyoun KIM, In Tak NAM, Yang Ki HONGArticle type: Article
Session ID: MMS200l-100
Published: November 08, 2001
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSThe BaM film and TiO_2 underlayer were prepared on(100) oriented bare Si substrate by using a RF/DC magnetron sputtering. BaM/TiO_2/Si thin films were crystallized at 750℃ and 800℃ by post-annealing. For most of BaM/TiO_2/Si thin films the coercivity values of the film prepared at 750℃ were higher than those of the film prepared at 800℃. High gas pressure was more effctive for BaM/TiO_2/Si thin film showing good maagnetic properties. The dependence surface morphology on annealing temperature was confirmed in BaM/TiO_2/Si film. Surface morphology was changed from elongated type grains to pop-corn type grains as increase in total gas pressure.View full abstractDownload PDF (575K) -
Dong Hyoun KlM, In Tak NAM, Yang Ki HONGArticle type: Article
Session ID: MMS200l-101
Published: November 08, 2001
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSThe BaM thin films and underlayers(Fe, Cr, Al_2O_3, Fe_2O_3, ZnFe_2O_4) were prepared on (100) oriented bare Si substrate by using a RF/DC magnetron sputtering system, and were compared with crystal orientation, magnetic properties and surface morphology. BaM/Cr/Si film revealed the highest coercivity of BaM films with all the underlayers. All the BaM films except BaM/Fe/Si film showed nearly same values of perpendicular and in-plane coercivities. Perpendicular anisotropy was observed in BaM/Fe/Si film. By adopting ZnFe_2O_4 as underlayer, the interdiffusion of Si from substrate was prohibited to some degree. Elongaed grains from the extinction of small parallet grains were grown with the increase of thickness at no underlayer film.View full abstractDownload PDF (653K) -
Peng Zhou, Dan WeiArticle type: Article
Session ID: MMS200l-102
Published: November 08, 2001
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSMetal particulate tape is one of the most advanced tape media to offer excellent performance at high recording densities. An accurate micromagnetic model of metal particulate tape has been developed to analyze the magnetic properties of MP tapes. Both particle size distribution and orientation distibution are included in this model and magnetostatic interactions among particles are accurately calculated with the shape of ellipsolds. A partial mean field approximation applied in the calculation is approved to be effective by M-H loop anaiysis.View full abstractDownload PDF (317K) -
Article type: Appendix
Pages App1-
Published: November 08, 2001
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSDownload PDF (86K)
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