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23.15
Displaying 1-17 of 17 articles from this issue
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Article type: Cover
Pages Cover1-
Published: February 25, 1999
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSDownload PDF (14K) -
Article type: Index
Pages Toc1-
Published: February 25, 1999
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSDownload PDF (78K) -
Nobuyuki Inaba, Masaaki FutamotoArticle type: Article
Session ID: VIR99-5
Published: February 25, 1999
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSImportant basic magnetic properties to design Co-based thin film media for high areal density magnetic recording are studied using the Co_<96-x>Cr_xTa_4 single crystal thin films(x=8-19at.%). The temperature dependence of saturation magnetization(M_s) and the Curie temperature(T_c) are determined. The M_<s0>(0K) and the T_c decrease linearly from 7.8×10^2 emu/cm^3, 8.2×10^2K to 4.0×10^2 emu/cm^3, 4.9×10^2K, respectively, with increasing the Cr content from 8 to 19at.%. The spontaneous magnetization(M_<s0> is lost at 33 at.% of Cr for the Co_<96-x>Cr_xTa_4system. The magnetic properties of polycrystalline film can be explained by taking into account of the Cr segregated microstructure.View full abstractDownload PDF (613K) -
Lea Pen Tan, Jian Ping WangArticle type: Article
Session ID: VIR99-6
Published: February 25, 1999
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSSubstrate texture effect on thermal instability for Co alloy thin film media are investigated. The orientation ratio of CoCrTa(Pt)/Cr media was controlled by the mechanical texture of the NiP/Al substrates. Bulk magnetic properties, delta M curves and time decay of magnetization along both circumferential and radial directions were measured. The maximum magnetic viscosity coefficient calculated from time decay of magnetization along circumferential direction was higher than that of radial direction for mechanically texture sample, while being similar along both directions for non-textured sample. The magnetic viscosity coefficient along circumferenetial direction is smaller than that along radial direction when the reverse field is in the range of the demagnetization field for thin film recording media. This implies that film with high orientation ratio will be more thermally stable when it is not exposed to large external magnetic field.View full abstractDownload PDF (491K) -
Liu Xiaoxi, Bai Jianmin, Wei Fulin, Yang Zheng, Akimitsu Morisako, Mit ...Article type: Article
Session ID: VIR99-7
Published: February 25, 1999
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSBa-ferrite thin films were successfully prepared by using a facing target sputtering system. Magnetic, crystallized thin films were obtained both by ex-situ and in-situ processes. In this paper, thin films prepared by these two processes were studied on the aspects of crtstal structure, magnetic properties and surface morphology It is found that the imperfection in the thin films strongly effects the magnetic properties of these filmsView full abstractDownload PDF (523K) -
M. Futamoto, K. Ito, Y. Hirayama, N. Inaba, Y. Honda, T. TakeuchiArticle type: Article
Session ID: VIR99-8
Published: February 25, 1999
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSThe recording and the signal decay characteristics of longitudinal and perpendicular thin film media are studied to investigate the limitations and the possibilities of CoCr-alloy thin film media. The CoCrTa and the CoCrPt perpendicular media show 25-32% higher recording resolution than those of the CocrPt longitudinal media. The medium S/N measured at 300 kFCI is in the order : CoCr_<20>Pt_<10>(L, 8nm)>CoCr_<17>Ta_4(P, 25nm)〜CoCr_<20>Pt_<10>(L, 16nm)>CoCr_<19>Pt_<10>(P, 25nm). The signal decay rates measured for a high Mr/Ms perpendicular medium is below 1 % per decade of time for all linear densities. The decay rate of longitudinal medium increases with increasing the linear recording density and with decreasing the recording layer thickness and it exceeds 10%/10^5 seconds at 300 kFCI with the thickness of 16 nm. The CoCr-alloy perpendicular recording media are promising, though the noise needs to be further reduced, to extend the linear density well beyond 400 kFCI which is likely needed to achieve the areal density greater than 20 Gb/in^2.View full abstractDownload PDF (801K) -
Satoshi YANASE, Naoki HONDA, Jun ARIAKE, Kazuhiro OUCHIArticle type: Article
Session ID: VIR99-9
Published: February 25, 1999
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSEffects of write condition of ring heads were investigated for low noise perpendicular recording media aiming at high density recording beyond 20 Gbit/in^2. Narrow head field distribution and high write efficiency is very essential for the ring head. A small write gap length less than 0.15 μm and a low flying height around 30 nm could realize saturation recording with a high recording resolution. Saturation recording became easier for the media with a steeper slope in perpendicular M-H loop. Output of a Co-Cr-Nb-Pt medium with a thin soft magnetic backlayer exhibited a high recording resolution and output using a merged GMR head with a small gap length. The medium with the backlayer could be a candidate medium for beyond 20 Gbit/in^2 areal density recording.View full abstractDownload PDF (680K) -
Naoki HONDA, Satoshi YANASE, Kazuhiro OUCHIArticle type: Article
Session ID: VIR99-10
Published: February 25, 1999
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSRing head recording on single layer perpendicular recording media was studied by a simple simulation analysis based on a loop tracing method considering only the perpendicular component. Although the assumed model was primitive, the simulation results qualitatively well explained experimental results such as decrease in output at high recording currents and improvement by using a smaller gap length head. The simulation also expected that a steeper slope in the perpendicular M-H loop of the media is significantly effective to improve the recording performance. This was confirmed by an experiment. However, the steeper loop slope in general has a drawback in the noise property. Thus the slope should have the optimal value which compromise recording and noise properties.View full abstractDownload PDF (698K) -
Mark S. Crowder, Dawn A. MarlowArticle type: Article
Session ID: VIR99-11
Published: February 25, 1999
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSWe report on a method used to characterize disk drive chemical outgassing and results on chemical outgassing dynamics. Chemical outgassing results indicate that the drive outgassing rate increases with drive temperature and the rate is exponentially dependent upon temperature (Arrenhius activation energy : 15 kcal/mole). The outgassing rate of a functional disk drive decreases, in a dual exponential fashion, with drive operation time and is discussed in terms of outgassing and offgassing phenomena. The applied value of determining outgassing properties of operational disk drives is it provides a means to correlate chemical characteristics with disk drive performance.View full abstractDownload PDF (560K) -
Bo LIU, Yaolong ZHU, Ying-Hui LI, Qingfang LENGArticle type: Article
Session ID: VIR99-12
Published: February 25, 1999
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSThis paper reports experimental setup and investigations into the nano-meter spaced head-disk interface based on the new setup. The effects of the lubricant, disk surface roughness and slider-disk interaction on the HDI system dynamics were studied. Results show that the flying stability of the slider depends not only on the ABS design, but also strongly on the disk surface roughness, lubricant as well as slider-disk interaction.View full abstractDownload PDF (741K) -
L. Pan, S.F. Ling, H.J. DuArticle type: Article
Session ID: VIR99-13
Published: February 25, 1999
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSThe track density of hard disk drives has been increasing about 30% annually and is expected to reach 25kTPI by the year 2000. A very promising way to achieve such high track density is to use a dual-stage actuator system. A new piezoelectricity driven dual stage actuator design consisting of two shear-mode PZT elements located at the base of the suspension is proposed in this paper. The dual stage actuator utilizes the opposite shear deformations of the two PZT elements under applied electrical potential to rotate the suspension and cause lateral slider motion. Finite element method is used to model and study the new dual stage actuator design on a typical suspension structure. The tip stroke response and dynamic characteristics of the dual stage actuator/suspension assembly are investigated. Simulation result shows the new shear-mode piezoelectric actuator to be a promising dual stage actuator system. Optimizing of the driving capacity can be achieved by a stacked piezoelectric design.View full abstractDownload PDF (450K) -
Wei Hua, Bo Liu, Sheng GangArticle type: Article
Session ID: VIR99-14
Published: February 25, 1999
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSIn hard disk drives, high density recording can only be achieved by providing an ultra-small spacing between the head and the disk. In other words, the slider housing the head at its real needs to fly as low as possible, and at the same time, excessive head/disk spacing fluctuations should be avoided. This concept is applicable as long as the ABS roughness and the disk surface roughness are much smaller, when compared with the slider/disk spacing. However, the head/disk spacing has entered the level of surface roughness in recent years, and the effects of the roughness can not be ignored any longer and needs to be investigated in detail. The authors observe in their experiments that the roughness of the disk surface may determine whether the specified sliders are fully flying or not, even though all the other experimental conditions are the same. In order to explain such a phenomenon, a probability model is developed for the investigation of the influence of surface roughness on the flying performance and the contact force of the slider. Simulations are conducted on both the contact recording slider and the proximity recording slider, and the results are well coordinated with the reported testing results and the self-conducted testing results. Studies are further extended to the characterization of the roughness of the ABS and the disk surface that may support head/disk spacing between 5nm and 15nm.View full abstractDownload PDF (856K) -
Gang Sheng, Bo Liu, Wei HuaArticle type: Article
Session ID: VIR99-15
Published: February 25, 1999
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSAn integrated slider-suspension system is designed and prototyped. This structure has full flying air-bearing surface in the leading part with contamination resistant feature, and it accommodates slider with 5〜15 nm head-disk spacing at the trailing part. Performance analysis and simulation were conducted to validate the design. The slider vibration had been studied systematically. It was found that the natural frequencies of slider motion are dependent on the disk contact stiffness, and slider vibrations exhibit varies of resonance under excitations. Finally, the random interaction of the interface was investigated, and the average response of slider body was derived.View full abstractDownload PDF (767K) -
Phan Le Kim, Cock LodderArticle type: Article
Session ID: VIR99-16
Published: February 25, 1999
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSIn this paper, we will present a study on magnetic viscosity of alumite perpendicular media at different thicknesses. Viscosity as a function of applied field(viscosity curve) exhibits a short plateau at low field and then decreases monotonously with increasing field. After correcting for the demagnetizing field, the shape of the intrinsic viscosity curves changes to the well-known shape of viscosity curve of in-plane media, i.e. they have a peak near H_c. The intrinsic viscosity curves obtained from experiments were fitted to an analytical model of Chantrell et al. [1], from which , we found that the effective switching volumes obtained by fitting are much smaller than the column volumes, indicating that the reversal mechanism is incoherent.View full abstractDownload PDF (777K) -
S.N. Piramanayagam, M. Matsumoto, A. MorisakoArticle type: Article
Session ID: VIR99-17
Published: February 25, 1999
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSThe effects of the sputter gas pressures during the deposition of the Pd underlayer (P_<ul>) and the Co/Pd multilayer(P_<ml>) on the magnetic and magneto-optic properties of Co/Pd multilayers are investigated. Mixing at the interface occurs with increase of sputter gas pressures. The increase of P_<ml> led to an increase in the coercivity, but to a decrease in the Kerr rotation angle. The increase of P_<ul> led to a decrease in the coercivity, a decrease in the Kerr rotation angle and also a change in the magnetization reversal mechanism. The films prepared at higher pressures exhibit aging properties and their magnetic properties deteriorate with time.View full abstractDownload PDF (642K) -
Tetsuya Mizuguchi, Teiichi MiyauchiArticle type: Article
Session ID: VIR99-18
Published: February 25, 1999
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSWe investigated the effect of the sputtering conditions on the properties of Ni80Fe20 and Ir22Mn78 films prepared by UHV-ICP(Inductively Coupled Plasma) magnetron sputtering system. Higher Ar pressure, lower cathode power and longer target-substrate distance for RF sputtering of IrMn resulted in larger exchange bias field for the structure glass/Ta(5nm)/NiFe(5nm)/IrMn(t_<IM>nm)/Ta(5nm). X-ray diffraction measurements showed that the exchange bias field depended on the spacing of lattice planes of IrMn. AFM observations showed that smaller coercivity of NiFe/IrMn were obtained for smaller grain diameter of IrMn. We obtained the maximum interfacial exchange coupling energy of 0.124 erg/cm^2 for t_<IM> of 5nm. The blocking temperature of 260 and 320℃ were obtained for t_<IM> of 5 and 12.5nm respectively.View full abstractDownload PDF (1564K) -
Article type: Appendix
Pages App1-
Published: February 25, 1999
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSDownload PDF (64K)
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