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Displaying 1-16 of 16 articles from this issue
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Article type: Cover
Pages Cover1-
Published: November 08, 2002
Released on J-STAGE: September 20, 2017
CONFERENCE PROCEEDINGS FREE ACCESSDownload PDF (12K) -
Article type: Index
Pages Toc1-
Published: November 08, 2002
Released on J-STAGE: September 20, 2017
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S. C. Oh, T. D. LeeArticle type: Article
Session ID: MMS2002-80
Published: November 08, 2002
Released on J-STAGE: September 20, 2017
CONFERENCE PROCEEDINGS FREE ACCESSMagnetic properties and thermal stability were studied in new antiferromagnetically coupled recording medium (AFC medium) with a CrMo spacer layer instead of the conventional Ru spacer Layer. It was found that a reduction of M_rt can be obtained in the new AFC medium with a CrMo spacer layer due to antiferromagnetic coupling similar to the conventional AFC medium with a Ru spacer layer. Also, the thermal stability factor, K_UV/k_BT for the proposed medium was slightly smaller than that of the conventional AFC medium with a Ru spacer layer, but larger than that of a single magnetic layer medium. From the results of SFD and ΔM, it is conjectured that the intergranular exchange coupling decreases when a CrMo is used as a spacer layer.View full abstractDownload PDF (504K) -
pyungwoo Jang, Sooyoul Hong, Jongryul KimArticle type: Article
Session ID: MMS2002-81
Published: November 08, 2002
Released on J-STAGE: September 20, 2017
CONFERENCE PROCEEDINGS FREE ACCESSSeveral kinds of 2 nm metal layer (M=Al, Cu, Ni, Cr, Ag, Mg, Fe, Co, Pd, Au, Pt, Mo, and Hf) were sputtered to increase Hc an Ku of CoCrPt/Ti perpendicular media. Among them Ag was very effective to increase Hc of (Co_<78>Cr_<22>)_<100-x>Pt_x/Ti(x=14, 20) films when 2 nm Ag, 18 nm Ti layer and 10-20 nm CoCrPt films were subsequently sputtered on Corning 7059 glass at 400℃. However, the effect was more pronounced when thickness of (Co_<78>Cr_<22>)_<100-x>Pt_x film was reduced to 10 nm. In addition α dedecreased when Ag layer was used. The film thickness below which Ag was effective was reduced if Pt content was decreased to 14 at. %. However, normal XRD experiment revealed that Ag did not promote c-axis growth of Ti and CoCrPt layer in the perpendicular direction. In the MFM observation domain size was reduced when Ag layer was introduced, which showed that films with good c-axis alignment could give lower Hc and wide domain width becasuse of strong magnetic coupling between grains.View full abstractDownload PDF (675K) -
D. H. Hong, J. N. Shin, S. Y. Hong, H. J. Lee, T. D. LeeArticle type: Article
Session ID: MMS2002-82
Published: November 08, 2002
Released on J-STAGE: September 20, 2017
CONFERENCE PROCEEDINGS FREE ACCESSIn this study, the effects of CoCrPtTa and CoCrPtB magnetic intermediate layers (IL) on the magnetic properties and read/write performance of CoCrPt/soft magnetic layer perpendicular recording media were investigated. Even though the perpendicular coercivity of the media with these IL was reduced by 500 Oe, these media still showed low exchange slope of 1.6 and large negative nucleation field of about -1000 Oe. Additionally, the reduced grain size of the media with these IL was observed by TEM. From the read/write test, these media with IL showed improved performance of 3〜5 dB higher SNR and OW compared to the media without IL. These enhancements could be attributed to the reduction of grain size of the magnetic layer and weakening of intergranular interaction between grains by insertion of the IL.View full abstractDownload PDF (528K) -
S. H. Kong, Takeshi Okamoto, Shigeki NakagawaArticle type: Article
Session ID: MMS2002-83
Published: November 08, 2002
Released on J-STAGE: September 20, 2017
CONFERENCE PROCEEDINGS FREE ACCESSTo reduce of grain size in recording layer, the new method which increase of the density of nucleation sites in the initial growth region by using the seedlayer with low γ_s was examined. The seedlayer with low γ_s was so effective to attain finer grain in magnetic upper-layers. The Ni-Fe-O intermediate layer was found to be effective in reduction of grain size as well as magnetic cluster size of Co-Cr-Ta-Pt recording layer. Furthermore, The reduction of grain size in Co-Cr-Ta-Pt redorcing layer on Ni-Fe-O intermediate with low γ_s led to decrease the noise level in the high recording density region.View full abstractDownload PDF (798K) -
Bo Liu, Mingsheng Zhang, Shengkai Yu, Leonard Gonzaga, Yuet Sim, Jianf ...Article type: Article
Session ID: MMS2002-84
Published: November 08, 2002
Released on J-STAGE: September 20, 2017
CONFERENCE PROCEEDINGS FREE ACCESSAs technology moves towards 600-1000 Gb/in^2, the mechanical spacing between head-silder and disk media must be reduced from current level of 10-12 nm to 3-4 nm. Such reduction of the head-disk spacing will be accompanied with a lot new challenges. One of them is how to reduce the flying height modulation caused by the waviness of disk surface. Reducing silder size from its current pico level to femto level is considered as a promising approach for such a challenge. However, discussions on femto slider are still limited to theoretical analysis and computer simulation. This paper reports authors' efforts in the fabrication of such sliders and experimental analysis of the dynamic performance of such femto sliders. Results indicate that the femto slider is advantages in reducing flying height modulation caused by the waviness of disk surface. Investigations also extend to the study of flying performance sensitivity of femto slider to the parameter offset caused by manufacturing and integration processes. Results indicate that the flying performance of the femto slider is more sensitive to such offsets, especially the crown/camber offset, comparing with pico sliders. Efforts also extend to discussion of slider ABS designs which are less sensitive to crown/camber offset.View full abstractDownload PDF (682K) -
Wei Zhang, Bo LiuArticle type: Article
Session ID: MMS2002-85
Published: November 08, 2002
Released on J-STAGE: September 20, 2017
CONFERENCE PROCEEDINGS FREE ACCESSAs technology moves towards further reduced head-disk spacing, the effects caused by inter-molecular level interactions between head-slider and disk media is becoming a severe stability concern of head-slider's position in both flying height direction and track following direction. Therefore, it is a need to explore simple but effective methods for the characterization of such two dimensional (2D) stability. The ideal methods should be easy to implement in both loboratory and quality control in disk drive and its component manufacturing. A reading process based in-situ method is explored in this work. The method is simple and can effectively reveal the 2D stability of the head-slider in both laboratory and manufacturing environment. Results obtained also suggest that the sway mode vibration of suspension can be excited earlier than tha air-bearing vibration mode, when flying height reduces. Further investigations indicate that a slider flying at a small skew angle makes the sway mode detection even more effective, comparing with the case when skew angle is zero.View full abstractDownload PDF (568K) -
Takayuki KUSUMI, Kiyoshi YAMAKAWA, Naoki HONDA, Kazuhiro OUCHIArticle type: Article
Session ID: MMS2002-86
Published: November 08, 2002
Released on J-STAGE: September 20, 2017
CONFERENCE PROCEEDINGS FREE ACCESSTo develop narrow track heads for high areal density recording systems, a basic system of quasi-static read/write tester was built up. The recording medium was reciprocally moved against a head with low speed sliding. Read/write tests were performed using the tester with double-layered perpendicular recording media and merged MR heads assembled on conventional HGA. A smooth sliding contact motion was realized, and the possibility for evaluating narrow track heads was confirmed. However, it is found that the head-to-medium spacing was varied depending on the moving direction, and the spacing in the backward motion, reverse of the conventional running direction for head sliders, was smaller than the flying height in a spin stand measurement. In addition, it was indicated that the recording condition has an advantage when the gap side of the upper pole becomes the recording point. as in the backward-directional recordingView full abstractDownload PDF (897K) -
C. Y. Poon, H. Wang, M. F. Chiah, W. Y. Cheung, N. Ke, S. P. WongArticle type: Article
Session ID: MMS2002-87
Published: November 08, 2002
Released on J-STAGE: September 20, 2017
CONFERENCE PROCEEDINGS FREE ACCESSIn this work, Fe-C thin films of various compositions were prepared by pulsed filtered vacuum arc deposition. The composition and thickness of the Fe_xC_<100-x> films were determined by non-Rutherford backscattering spectrometry. The structures and magnetic properties were studied using x-ray diffraction, transmission electron microscopy, x-ray photoelectron spectroscopy, atomic force microscopy, magnetic force microscopy, and vibrating sample magnetometry. The resistivity was measured by the four contact technique from 20K to 300K. Thermal annealing was performed in vacuum for 1 h at various temperatures ranging from 200 to 500℃. The dependence of the structures and properties on composition and annealing conditions were studied. For the as-deposited film with a particular composition of Fe_<90>C_<10>, it showed an amorphous structure and soft magnetic properties with a high saturation magnetization of 1550 emu/cm^3, a small coercivity of 7 Oe and a moderate resistivity of 90 μΩ-cm at room temperature.View full abstractDownload PDF (625K) -
X. H. Li, X. H. Wei, Y. G. Ma, Z. Yang, F. L. WeiArticle type: Article
Session ID: MMS2002-88
Published: November 08, 2002
Released on J-STAGE: September 20, 2017
CONFERENCE PROCEEDINGS FREE ACCESS45-55 NiFe films were deposited onto (100) Si substrate via radio frequency (RF) magnetron sputtering. The influence of composition, RF input power, argon pressure, substrate-to-target distance on the magnetic and structural properties of the films was investigated. X-ray diffraction measurements indicate that the films had the fcc structure and exhibited a dominant (111) orientation. The average grain sizes of films were 14-35nm. The maximum saturation magnetization (4 π Ms〜1.6×10^4 Gauss) could be obtained for films with the composition Fe_<54.5>Ni_<45.5>. Depending on deposition conditions, the films coercivity could be varied from 10 to 60 Oe. After annealing in 400℃ for an hour, the particles grew bigger with size 30-50nm, the films orientation did not change obviously, still showe (111) orientation, and the coercivity decreased.View full abstractDownload PDF (318K) -
Ohsung Song, Kiyung LeeArticle type: Article
Session ID: MMS2002-89
Published: November 08, 2002
Released on J-STAGE: September 20, 2017
CONFERENCE PROCEEDINGS FREE ACCESSWe fabricated MTJ devices that have doubly oxidized tunnel barrier using plasma oxidation method to from oxidized AlOx tunnel barrier. Doubly oxidation I, which sputtered 10 Å-bottom Al layer and oxidized it with oxidation time of 10 s. Subsequent sputtering of 13 Å-Al was performed and the metallic layer was oxidized for 50, 80, and 120 s, respectively, Doubly oxidation II, which sputtered 10 Å-bottom Al layer and oxidized it varying oxidation time for 30〜120 s. Subsequent sputtering of 13 Å-Al was performed and the metallic layer was oxidized for 210 sec. Doubly oxidation process specimen showed MR ratio of above 27% in all experiment range. Singly oxidation process, 13 Å-Al layer and oxidized up 210 s, showed less MR ratio and more narrow process window than those of doubly oxidation. Cross-sectional TEM images showed that doubly oxidized barrowers were thinner and denser singly oxidized ones. XPS characterization confirmed that doubly oxidation prevented oxidation of Fe with bottom insulating layer. As the result, doubly oxidation could have superior MR ratio in process extent during long oxidation time because of preventing oxidation of bottom magnetic layer than singly oxidation.View full abstractDownload PDF (580K) -
Xuan Zhang, Dan WeiArticle type: Article
Session ID: MMS2002-90
Published: November 08, 2002
Released on J-STAGE: September 20, 2017
CONFERENCE PROCEEDINGS FREE ACCESSA micromagnetic model is established to analyze the storage mechanism of Magnetoresistive Random Access Memories (MRAM) based on Magnetic Tunnel Junctions (MTJ). The MTJ cell consists of a free layer, an oxide barrier layer, a synthetic antiferromagnetic sandwich (Co/Ru/Co), and an antiferromagnetic pinning layer. The magnetostatic interaction between the three ferromagnetic layers are precisely considered. Based on this model, the M-H loop of the NiFe free layer in a MTJ cell is calculated under different sizes. The interference among different MTJ cells in MRAM is also discussed.View full abstractDownload PDF (433K) -
Toshitaka KOJIMA, Hisashi HOTTA, Takashi ASAI, Yiwei HeArticle type: Article
Session ID: MMS2002-91
Published: November 08, 2002
Released on J-STAGE: September 20, 2017
CONFERENCE PROCEEDINGS FREE ACCESSThe present paper deals with the ferquency-dependent finite difference time domain ((FD)^2TD) method analysis of the light-beam diffraction from a land/groove recording phase-change (PC) optical disk model with metal (Al or Au) reflective layer in order to improve the conventional analysis for PC optical disk models under the assumption of perfectly conducting reflective layer (PCRL). The diffracted fields are numerically calculated for both recorded and non-recorded states of the recording layer, and the comparison of the diffraction characteristics between two states is discussed. The crosstalk between the recording marks on lands and grooves are evaluated and the optimum groove depth is examined.View full abstractDownload PDF (603K) -
Article type: Appendix
Pages App1-
Published: November 08, 2002
Released on J-STAGE: September 20, 2017
CONFERENCE PROCEEDINGS FREE ACCESSDownload PDF (74K) -
Article type: Appendix
Pages App2-
Published: November 08, 2002
Released on J-STAGE: September 20, 2017
CONFERENCE PROCEEDINGS FREE ACCESSDownload PDF (74K)
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