巻号一覧
22 巻, S_3_PMRS_98 号
選択された号の論文の12件中1～12を表示しています
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垂直磁気記録媒体
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本多 直樹, 木谷 貴則, 有明 順, 呉 連軍, 大内 一弘1999 年 22 巻 S_3_PMRS_98 号 p. S3_1-4
発行日: 1999年
公開日: 2011/12/15
ジャーナル オープンアクセスDesign concept for low noise perpendicular recording media is proposed based on an in-bit reversed domain model. Although smaller reversed domains and a higher SQ⊥ are expected to be essential for low noise property, substantial noise is observed for films with SQ⊥=1 due to reversed domains formed in the recording process. The noise is decreased for films with a smaller M-H loop slope. It was indicated that the loop slope has opposite effects on the noise and recording properties of the media. Improvement in the recording head and realization of new low noise media with a square M-H loop are the present issues.抄録全体を表示PDF形式でダウンロード (749K) -
平山 義幸, 本多 幸雄, 伊藤 研也, 竹内 輝明, 二本 正昭1998 年 22 巻 S_3_PMRS_98 号 p. S3_5-8
発行日: 1998年
公開日: 2011/12/15
ジャーナル オープンアクセスThickness dependence of noise characteristics and thermal decay have been investigated for CoCr19Pt10 and CoCr17Ta4 single-layer perpendicular media. The thermal stability of recorded bit is improved by making Mr/Ms ratio close to 1. The maximum S/N ratios are observed for both-type media when the recording layer thickness is around 25 um. Good correlation between the magnetic domain size and the noise value shows that it is necessary to decrease the magnetic domain size to reduce the medium noise.抄録全体を表示PDF形式でダウンロード (628K) -
法橋 宏高, 坪井 眞三, 大嶋 則和, 田上 勝通1998 年 22 巻 S_3_PMRS_98 号 p. S3_9-12
発行日: 1998年
公開日: 2011/12/15
ジャーナル オープンアクセスDouble-layer media with single pole heads are the ideal way of perpendicular magnetic recording. However, unstableness of recorded magnetization originating from magnetic domains of underlayers have not been settled. We investigated signal stability of the media using NiFe underlayers and the media using FeSiAl underlayers, which take the diferent magnetization process from NiFe underlayers. The results show that the media using FeSiAl showed better stability of recorded magnetization than those using NiFe.抄録全体を表示PDF形式でダウンロード (771K) -
佐藤 賢治, 吉田 祐樹, 奥山 智明, 岡本 巌, 篠原 正喜1998 年 22 巻 S_3_PMRS_98 号 p. S3_13-16
発行日: 1998年
公開日: 2011/12/15
ジャーナル オープンアクセスDemagnetizing Fields in recorded bits accelerated thermal decay of data output in magnetic recording media. The spread of transition area also promotes the reduction of obtained data output. We compared the time dependencies of data output at several recording densities when a spin stand was used with the time dependencies of the remanent magnetization in various applied fields. The various applied fields corresponded to the demagnetizing fields in the recorded bits at their respective recording densities. We have experimentally confirmed that reproduced output reduction can explained by considering the degradation of both magnetization and transition length for longitudinal recording media. We have also experimentally confirmed that output reduction can be reduced by putting a soft magnetic underlayer for perpendicular media.抄録全体を表示PDF形式でダウンロード (702K)
次世代垂直磁気記録媒体
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小野寺 誠一, 岩生 仁志, 佐本 哲雄, 川名 隆宏, 池田 義人, 尾末 匡1998 年 22 巻 S_3_PMRS_98 号 p. S3_17-20
発行日: 1998年
公開日: 2011/12/15
ジャーナル オープンアクセスWe investigated thin metal evaporated tapes with MR heads in a helical scanning system, trying to achive a high recording density. We found that ME tape can realize low Mr•t values by changing the amount of oxygen during evaporation and thickness of magnetic layer to obtain a low noise media. Thin ME tapas are suitable media for high sensitivity heads such as MR heads.抄録全体を表示PDF形式でダウンロード (719K) -
山本 節夫, 山時 照章, 栗巣 普揮, 松浦 満, 香嶋 純, 中田 健一, 柿原 康男, 土井 孝紀, 田万里 耕作1998 年 22 巻 S_3_PMRS_98 号 p. S3_21-25
発行日: 1998年
公開日: 2011/12/15
ジャーナル オープンアクセスIn the fabrication process of Co-γFe2O3/NiO thin film recording disks, new oxidization method using oxygen ions in a plasma was proposed to transform a CoO-Fe3O4 film to a Co-γFe2O3 film. Remarkably effective oxidization was achieved by utilizing oxygen ions produced in an electron-cyclotron-resonance microwave plasma, promotion of oxygen ion generation by Penning ionization effect using metastable He atoms, and neutralization for preventing static electricity of samples. This plasma oxidization method shortened the oxidization processing time to 10 seconds and lowered the process temperature to 150 °C for the 20nm thick CoO-Fe3O4 films. Almost same recording characteristics was obtained between the Co-γFe2O3/NiO disks prepared by the plasma oxidization method and a conventional heat oxidization method in air.抄録全体を表示PDF形式でダウンロード (713K) -
松下 伸広, 馮 潔, 渡部 康, 村社 智宏, 中川 茂樹, 直江 正彦1998 年 22 巻 S_3_PMRS_98 号 p. S3_27-31
発行日: 1998年
公開日: 2011/12/15
ジャーナル オープンアクセスIn the first half of this work, a magnetoplumbite-type of Ba ferrite (BaM) layers were deposited from BaFe11O19-y targets and BaFe13O19-y ones on a ZnO(001) underlayer in a gas mixture of Ar, Xe, and O2 using facing targets sputtering apparatus. It was clarified that a stoichiometric composition is necessary for preparing Ba ferrite films with large saturation magnetization 4πMs and excellent perpendicular anisotropy. Ba ferrite films deposited at optimum conditions exhibited large 4πMs of 4.7 kG and high perpendicular coercivity Hc⊥ of 2.4 kOe and low in-plane one Hc// of 0.2 kOe even when substrate temperature Ts was as low as 475°C. In the latter half of this work, Al substituted Ba ferrite films were deposited from BaFe11Al1O19-y targets and BaFe10Al2O19-y ones on Pt (111) underlayer for increasing Hc⊥ and perpendicular squareness Sc⊥. Although 4πMs decreased with increase of substitution amount x, Hc⊥ increased even for as-deposited films. S⊥ increased after annealing at 850-900°C for 15 min in air the maximum S⊥ of 0.91 was attained for films deposited from BaFe10Al2O19-y target.抄録全体を表示PDF形式でダウンロード (622K)
信号処理
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大沢 寿, 岡本 好弘, 斎藤 秀俊, 村岡 裕明, 中村 慶久1998 年 22 巻 S_3_PMRS_98 号 p. S3_33-37
発行日: 1998年
公開日: 2011/12/15
ジャーナル オープンアクセスThe partial response maximum-likelihood (PRML) systems for perpendicular magnetic recording using an MR head and a double-layered medium are studied. The bit error rate performance of PRML systems characterized by the polynomials with the positive coefficients and conventional PRML systems with the negative coefficients for the 16/17(0,6/6) code is evaluated by computer simulation. Among PRML systems discussed in this study, PR(1,2,2,1)ML exhibits the best performance and improves the SNR by about 6.2dB over that of EPR4ML at a bit error rate of 10-4 and a normalized linear density of 2.5. At high linear density, the performance of PR(1,2,3,2,1) ML for the 16/17(0,6/6) code is superior to that of PR(1,2,3,2,1)ML for the (1,7)RLL code.抄録全体を表示PDF形式でダウンロード (599K) -
池谷 章, 小林 正明, 田崎 三郎1998 年 22 巻 S_3_PMRS_98 号 p. S3_39-46
発行日: 1998年
公開日: 2011/12/15
ジャーナル オープンアクセスThis paper describes a systematic construction method of Run Length Limited (RLL) codes for the purpose of getting higher recording density realized. The continuous number of a binary value in the RLL code is restricted to not less than d and not greater than k in NRZL notation by converting a data word of m-bit to a codeword of n-bit. This method comprises; a) equations for calculating the number of the codewords; b) rules for selecting codewords; c) rules for concatenating the codewords. Various kinds of fixed length or variable length RLL codes have been gotten under the conditions of d= 1, 2, ···, 6, k= d+1, ···, 15 in NRZL expression, and n= d+1, ···, 32.抄録全体を表示PDF形式でダウンロード (826K)
記録再生特性とストレージシステム
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村岡 裕明, 三浦 健司, 杉田 愃, 中村 慶久1998 年 22 巻 S_3_PMRS_98 号 p. S3_47-52
発行日: 1998年
公開日: 2011/12/15
ジャーナル オープンアクセスDigital signal evaluation for a thin-film single-pole head and double layer perpendicular disk was carrited out with an error rate tester. An AMR head was used as a reading head. The channel of the tester was the PR4ML with the 8/9 endec. Waveform for the MR head was transformed with a differentiator consisted of passive LCR circuitry and high speed linear amplifier. A D50 of 185 kFRPI, a PW50 of 130 nm, and an NLTS at 300 kFRPI were measured. A byte error rate of 10-6 was obtained at 310 kFRPI for a read trackwidth of 1.4 μm.抄録全体を表示PDF形式でダウンロード (867K) -
鈴木 良夫1998 年 22 巻 S_3_PMRS_98 号 p. S3_53-56
発行日: 1998年
公開日: 2011/12/15
ジャーナル オープンアクセスA new method of field calculation for head-medium systems was developed. The new method is accurate, quick to execute, and compact, without requirement for a special mesh making process. The new method can be applied to various problems including, the medium field and the self demagnetizing field calculations for MR heads, and the head medium interaction calculation in the recording process.抄録全体を表示PDF形式でダウンロード (555K) -
栗岡 辰弥, 沼津 潤二1998 年 22 巻 S_3_PMRS_98 号 p. S3_57-61
発行日: 1998年
公開日: 2011/12/15
ジャーナル オープンアクセスIn the age of digital multimedia, demand is bound to rise for television Home Servers that automatically record a viewer's favorite programs so that he/she can watch them at any time. We have developed an experimental Home Server on which a recorded HDTV program can be played back while recording another digital HDTV program. Using a new HSMS (hierarchical storage management system) we proposed, it was able to store HDTV programs for 4 hours and was as small as thickness of flat displays. This paper describes the outline of the experimental system and aims to clarify the recording requirements for hard disks and tapes by examining the read/write performance of hard disks on multi-channels and the nonlinear accessibility to programs recorded on tapes.抄録全体を表示PDF形式でダウンロード (724K)
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