WO1998057324A1 - Magnetic recording medium and magnetic recorder/reproducer - Google Patents

Magnetic recording medium and magnetic recorder/reproducer Download PDF

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Publication number
WO1998057324A1
WO1998057324A1 PCT/JP1997/002017 JP9702017W WO9857324A1 WO 1998057324 A1 WO1998057324 A1 WO 1998057324A1 JP 9702017 W JP9702017 W JP 9702017W WO 9857324 A1 WO9857324 A1 WO 9857324A1
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WO
WIPO (PCT)
Prior art keywords
magnetic
coercive force
magnetic recording
cocr
recording medium
Prior art date
Application number
PCT/JP1997/002017
Other languages
French (fr)
Japanese (ja)
Inventor
Kazusuke Yamanaka
Tomoo Yamamoto
Nobuyuki Inaba
Masaaki Futamoto
Masukazu Igarashi
Yasutaroo Uesaka
Original Assignee
Hitachi, Ltd.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
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Publication date
Application filed by Hitachi, Ltd. filed Critical Hitachi, Ltd.
Priority to PCT/JP1997/002017 priority Critical patent/WO1998057324A1/en
Publication of WO1998057324A1 publication Critical patent/WO1998057324A1/en

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Classifications

    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/62—Record carriers characterised by the selection of the material
    • G11B5/64—Record carriers characterised by the selection of the material comprising only the magnetic material without bonding agent
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/012—Recording on, or reproducing or erasing from, magnetic disks
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/127—Structure or manufacture of heads, e.g. inductive
    • G11B5/31—Structure or manufacture of heads, e.g. inductive using thin films
    • G11B5/3109—Details
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/127—Structure or manufacture of heads, e.g. inductive
    • G11B5/33—Structure or manufacture of flux-sensitive heads, i.e. for reproduction only; Combination of such heads with means for recording or erasing only
    • G11B5/39—Structure or manufacture of flux-sensitive heads, i.e. for reproduction only; Combination of such heads with means for recording or erasing only using magneto-resistive devices or effects
    • G11B5/3903—Structure or manufacture of flux-sensitive heads, i.e. for reproduction only; Combination of such heads with means for recording or erasing only using magneto-resistive devices or effects using magnetic thin film layers or their effects, the films being part of integrated structures
    • G11B5/3967—Composite structural arrangements of transducers, e.g. inductive write and magnetoresistive read
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B2005/0002—Special dispositions or recording techniques
    • G11B2005/0005—Arrangements, methods or circuits
    • G11B2005/001—Controlling recording characteristics of record carriers or transducing characteristics of transducers by means not being part of their structure

Definitions

  • the present invention relates to a ferromagnetic metal thin film magnetic recording medium, and in particular, to a magnetic recording medium having excellent electromagnetic conversion characteristics and a large-capacity magnetic recording / reproducing apparatus.
  • the size of the magnetization reversal unit is related to the magnetic viscosity. In other words, the larger the magnetic viscous fluctuation field, the greater the magnetization reversal. The unit is considered small.
  • I (t) const. ⁇ S ⁇ Int (1) It often changes.
  • I (t) is the magnetic moment per unit volume
  • t is the elapsed time after applying a new magnetic field.
  • the viscosity coefficient S has a positive value when the magnetic field is shifted in the positive direction and the printing force is tl, and a negative value when the magnetic field is shifted to the negative direction. It is also known that S is represented by the product of the irreversible susceptibility% irr and the fluctuation field. That is,
  • the fluctuation field is an amount that indicates the magnitude of the effect of the thermal fluctuation.A large fluctuation field is susceptible to the thermal fluctuation and a small unit of magnetization reversal. Means.
  • H c (or H r ) — ⁇ ⁇ Int + const. (3)
  • H c (or H r ) — ⁇ ⁇ Int + const. (3)
  • the relationship of the formula (3) was established.
  • the time for applying the magnetic field was set to 8 seconds to 30 minutes. If coercivity or remanence varies according to magnetic field application time t according to equation (3), B indicates coercivity or remanence coercivity in magnetic field strength etc. does O coercive and swinging, et al Technical field H f of an equal arbitrariness and this filtered to show the same value. This method is simple and has good reproducibility.
  • the value of B is used as a magnetic fluctuation field.
  • Vb kT / H f (5)
  • the activation volume V is obtained according to (Journa 1 of Physics F: Metal Physics) 14 vol. L155 ⁇ 159 pages (issued in 1984).
  • k is the Boltzmann constant
  • T is the absolute temperature
  • I sb is the spontaneous magnetization of the magnetic part in the magnetic film.
  • V ⁇ I sb of the activation volume V and the spontaneous magnetization I sb represents the size of the unit of magnetization reversal. According to the inventors, the smaller v * I sb is, the smaller the medium It was clear that the noise was low (Journal of Magnetism and End Magnetism).
  • Equation (4) holds when the range of the application time of the measurement magnetic field is relatively narrow. Actual write (Pulse application time: ⁇ 10 8 seconds) or, et al. Storage: In a broad range Ru optimal (10 years to 10 8 seconds),
  • H 0 H 0 ⁇ 1- [Cln (At / 0.693)] 1/2 ⁇ (6) is in good agreement with the measured value (II-transactions) IE EE TRANSACTIONS ON MAGNETICS MAG-20 vol. 754-756 (issued in 1994).
  • H 0 is a coercive force when there is no influence of thermal fluctuation
  • C is a fitting parameter. . Is found in the A value of 10 9 / s in the frequency of the scan pin precession DOO et is Ru.
  • a Cr underlayer is formed on a mirror-polished disk made of an A1-Mg alloy coated with an electroless plating Ni-P, and then a CoCrTa magnetic layer is formed.
  • a magnetic disk was fabricated by forming a carbon protective film.
  • the Cr underlayer, magnetic layer, and protective film were all formed by sputtering using Ar gas.
  • the substrate temperature was 300 ° C
  • the Ar pressure was 2.0 milliTorr.
  • the thickness of the Cr underlayer is 50 nm
  • the thickness of the magnetic layer is 25 nm
  • the thickness of the protective film is 10 nm.
  • the composition of the CoCrTa magnetic layer is represented by atomic%, and is C0: 80%, Cr: 16%, and Ta: 4%. This composition is hereinafter referred to as CoCr 16 Ta 4 in this specification.
  • the remanence coercive force H r of this medium was 2430 Oe.
  • Temperature coefficient of Remane Nsu coercive force was measured by C - dH r / dT was Tsu Oh at 7. 96 Oe / deg.
  • the magnetic information is recorded on the above medium using a permalloy head having a gap length of 0.4 ⁇ 24 turns per person, The reproduction was performed using a 1-malloy magnetoresistive head, and the electromagnetic conversion characteristics were examined. At this time, the flying height during recording and playback was 80 nm.
  • the purpose of the present invention is to reduce the noise during reproduction, suppress the temperature coefficient of coercive force to a low value, and withstand a 2 gigabit operating temperature of 0 to 60 ° C.
  • An object of the present invention is to provide a magnetic recording medium and a magnetic disk device having a recording density of at least a square inch. Disclosure of invention
  • FIG. 1 is an enlarged sectional view of a magnetic recording medium according to the present invention.
  • reference numeral 1 denotes a non-magnetic substrate made of aluminum-magnesium alloy, glass, carbon, or the like on which Ni-P is adhered.
  • 2 is a non-magnetic underlayer for controlling the crystal orientation and crystal grain size of the magnetic film, and is a metal layer such as Cr, Cr-Mo, Cr-W, Cr-Ti, Cr-V, etc.
  • Help. 3 is Co-Cr-Ta, Co-Cr-Ta-Ni, Co-Cr-Pt, Co-Cr-Pt-Ta, Co-0, Co-Ni, Co PT / JP97
  • a ferromagnetic thin film mainly composed of knots. 4 is a protective lubricating layer, such as carbon film, oxide film, plasma polymer film, fatty acid, perfluorocarboxylic acid, perfluoropolyether, and the like. Can be used alone or as a complex.
  • the magnetic layer 3 has a temperature coefficient of coercive force of 7 Oe / deg or more and 12 Oe / deg or less, and has a remanence coercive force of H when there is no influence of thermal fluctuation.
  • the temperature coefficient is 1.7 X ⁇ (H 0- ⁇ ⁇ ) / / ⁇ and the coercive force is
  • a ferromagnetic thin film of 2000 Oe or more is used, and the thickness of the magnetic layer is desirably 5 nm or more and 30 nm or less.
  • the ferromagnetic thin film is a covanolate-based magnetic alloy containing at least one of the group consisting of Cr, Ta, Pt, Ni, Mo, V, Ti, Zr, Hf, Si, W, and zero.
  • Thin films such as * Co-Cr-Ta, Co_Cr-Ta-Ni, Co-Cr-Pt, Co-Cr-Pt-Ta, Co-0, Co-Ni, Co-Cr, Co-Mo, Co_Ta, It is desirable that the film be a thin film containing Co / Ni—0, such as Co—Ni—Cr—Co—Ni—0.
  • the obtained coercive force or the coercive force H 0 in the case where there is no influence of thermal fluctuation is obtained from the dependency of the remanence coercive force on the magnetic field application time according to equation (6). You can do it.
  • the fluctuation field obtained from the dependence of the coercivity on the magnetic field application time shows almost the same value as the fluctuation field obtained from the dependence of the remanence coercivity on the magnetic field application time.
  • the fluctuation field was determined from the dependence of the remanence coercivity on the magnetic field application time.
  • the measurement was performed using a vibrating magnetometer manufactured by DMS (Digital Measurement Systems), the measurement temperature was 25 ⁇ 3 ° C, and the time for applying a magnetic field after DC degaussing was 8 seconds to 30 minutes.
  • the coercive force Hc was obtained by a normal hysteresis measurement.
  • the remanence coercive force ⁇ ⁇ was a value when the magnetic field application time was 8 seconds.
  • Temperature coefficient of H r (- dH r / dT ) was gradient mosquito ⁇ Motomu Luo because the temperature change of H r measured between. 20 to 60 ° C.
  • the remanence coercive force When the temperature coefficient of the remanence coercive force is 7 Oe / deg or more and 12 Oe / deg or less, the remanence coercive force is H 0 when there is no effect of thermal fluctuation, and the remanence coercivity is H.
  • the magnetic force is H r and the absolute temperature is T
  • the use of a ferromagnetic thin film having a temperature coefficient of 1.7 X ⁇ (H 0 -H r ) / T ⁇ or less will help The S / N of the medium can be increased while appropriately controlling the temperature coefficient of the magnetic force.
  • the performance of a medium capable of recording steeply can be improved. Since it can be pulled out, a high-density recording / reproducing apparatus of 2 gigabits / square inch or more can be provided.
  • FIG. 1 is a diagram showing a basic structure of the ferromagnetic metal magnetic thin film medium of the present invention
  • FIG. 2 is a diagram showing a product V ⁇ I sb of an activation volume V and spontaneous magnetization I sb and a remanence coercive force.
  • FIG. 3 is a correlation diagram of the product v 'I sb and Bruno size b of the activation volume V and the own Hatsu ⁇ of I sb
  • FIG. 4 is a structural diagram of the magnetic head
  • FIG. 5 is a structural diagram of the magnetic disk device
  • FIG. 6 is a diagram showing the activation volume V and the spontaneous magnetization Isb .
  • FIG. 7 is a correlation diagram between the product ⁇ ⁇ I sb and the temperature coefficient of the coercivity of the remanence -dH r / dT.
  • FIG. 8 is a correlation diagram between the product ⁇ ⁇ I sb of the magnetization I sb and the noise, and FIG. 8 shows the product ⁇ ⁇ I sb of the activation volume V and the spontaneous magnetization I sb and the remanence coercive force.
  • Fig. 9 shows the correlation between the noise ⁇ and ⁇ b of the activation volume V and the spontaneous magnetization I sb, and the noise with the temperature coefficient-dH r / dT of . Best mode for carrying out the invention
  • An underlayer of Cr alloy is formed on a mirror-polished disk made of Al-Mg alloy coated with Ni-P of electroless plating, and then a CoCrPt or CoCrPtTi magnetic layer is formed.
  • a magnetic disk was fabricated by forming a carbon protective film.
  • the Cr alloy underlayer, magnetic layer, and protective film were all formed by sputtering using Ar gas. At this time, the Ar pressure was set at 2.0 milliTorr.
  • the underlayer has two layers consisting of a single layer of Cr-V, Cr-W, Cr-Ti, Cr-Si or Cr-Mo alloy or a layer of a different kind of metal. For this purpose, a total of 43 samples having different base composition were prepared.
  • the total thickness of the Cr alloy layer is 20 to 50 nm
  • the thickness of the CoCrPt or CoCrPtTi magnetic layer is 3 to 30 ⁇ m
  • the thickness of the protective layer is 10 nm.
  • the Cr content of the CoCrPt magnetic layer was set at 22 to 20 atomic percent, and the Pt content was set at 4 to 10 atomic percent.
  • the CoCrPtTi magnetic layer contains CoCr 20 Pt 10 Ti 4 or CoCr 20 Pt 8 Ti 4 was used.
  • the Cr content of these magnetic layers is larger than those of Comparative Examples 1 and 2 described later.
  • the coercive force H c of the obtained medium was distributed in the range of 1400 to 28000 e.
  • the product ⁇ ⁇ I sb between the subject and the activation volume V issued magnetization I s b is the distribution in the range of 0.60 or et al 3. 67 X l (T 15 emu , Les while the value down the scan coercive
  • the temperature coefficient of magnetic force -dHf / dT ranged from 3.7 to 14.2 Oe / deg.
  • the magnetic information was recorded on the above medium using a No. 1 head having a gap length of 0.4 / zm and a winding number of 24 turns, and the No.
  • the head was reproduced with a head and the electromagnetic conversion characteristics were examined.
  • the recording height was set at 80 nra during recording.
  • the noise at a linear recording density of 150 kFCI was 8 to 31 ⁇ V rms .
  • re-raw output was Tsu Oh in 0.5 or et al. 1. 45 m V p _ p.
  • Magnetic film composition, magnetic MakumakuAtsu, the coercive force, Roh of I's measurement results, measurement or Motomu Luo because was the value of V ⁇ I sb of the magnetic viscosity, in the range of your good beauty 20 or 60 ° C, et al.
  • Table 1 summarizes the temperature coefficient of the remanence coercive force of the above.
  • Magnetic film composition Magnetic film film Coercive force H c noise v ⁇ I s b (X-dH r / dT
  • the temperature coefficient of the coercive force is affected by the thermal fluctuation obtained by fitting the data of the dependency of the remanence coercive force on the magnetic field application time using equation (6).
  • V ⁇ Isb becomes smaller.
  • the magnetic disk device shown in Fig. 5 was fabricated.
  • 201 is a recording magnetic pole
  • 202 is a magnetic pole and magnetic shield layer
  • 203 is a coil
  • 204 is a magnetic material having a high saturation magnetic flux density
  • 205 is a magnetoresistive element
  • 206 is a magnetic resistance effect element.
  • a conductor, 207 is a magnetic shield layer
  • 208 is a slider base.
  • reference numeral 211 denotes a magnetic recording medium
  • 212 denotes a magnetic recording medium driving unit
  • 213 denotes a magnetic head
  • 214 denotes a recording / reproducing signal processing system
  • 215 denotes a magnetic head driving unit.
  • FIG. 2 shows a 2-gigabyte data using the above magnetic recording / reproducing apparatus.
  • the measurement results of the reading error when measured at a recording density of bit / square inch at room temperature and at 60 ° C are indicated by ⁇ , ⁇ and-marks.
  • O mark the e la over rate shows and this was Tsu Oh in practical use possible and thinking we are Ru 10 11 hereinafter also the room temperature you good beauty 60 ° C
  • ⁇ is
  • - mark indicates a call was Tsu Oh 10 11 or more on the also the room temperature you good beauty 60 ° C.
  • Fig. 2 A magnetic disk device with a recording density of 2 gigabits / square inch or more, which enables practical use of error rates at room temperature and 60 ° C. and the shall be the thinking et been Ru 10 11 or less, the temperature coefficient of Remane Nsu coercivity 7 0e / deg force, et 12 0e / deg, and 1. 7 ⁇ ( ⁇ .- ⁇ ⁇ ) / ⁇ less In some cases, you need to use the same medium. In most cases from Table 1, media satisfying this condition have a coercive force of 20000 e or more and a magnetic film thickness of 10 nm or more and 25 nm or less. Is limited to
  • V - I sb is Ri Oh less than about 1. 5 X l (T 15 emu , a large can have force Ri by temperature coefficient is 12 Oe / deg, 1. 7 X (H.- H r) / T by Ri large At high temperatures, it was possible to fabricate a magnetic disk device with low noise at room temperature and a recording density of 2 gigabits Z square inch, but 2 gigabits. bit Z square stomach as a child you your only that e la Moltrasio over door to 10 11 below to 60 ° C in the recording density of the bench was Tsu Oh difficult.
  • a medium having a temperature coefficient force of less than 7 Oe cannot provide a medium having a small V ⁇ I sb , resulting in a high noise, and in this case also a 2 gigabit squared. It has not been possible to fabricate magnetic disk devices of more than one inch.
  • the medium had a coercive force of 2000 Oe or less, and the resolution was low as well as the output.
  • a Cr alloy underlayer was formed on a mirror-polished disk made of an A1-Mg alloy coated with electroless Ni-P, followed by a CoCrTa magnetic layer, Then, a carbon protective film was formed on the magnetic disk.
  • the Cr alloy underlayer, magnetic layer, and protective film were all formed by sputtering using Ar gas. At this time, the Ar pressure was set to 2.0 milliTorr.
  • the Cr alloy underlayer a total of 22 samples having different underlayer compositions were prepared using Cr-V, Cr-W, Cr-Ti, Cr-Si, and Cr-Mo.
  • the thickness of the Cr alloy layer is 50 nm
  • the CoCrTa magnetic layer is 19 or 25 nm
  • the protective layer is 10 nm.
  • the composition of the CoCr Ta magnetic layer was CoCri 5 Ta 4 , CoCr 18 Ta 4 and CoCr 16 Ta 6 .
  • the coercive force H c of the resulting media and will this 1500 to 2420 0e Distributed in the range. Also, the product [nu ⁇ I sb 1.72 power of the activation volume V and spontaneous magnetization I s b, and the distribution in the range of al 3.64X 10- 15 emu, the temperature coefficient of Remane emission scan coercivity - dH r / dT ranged from 4 to 6.8 Oe / deg.
  • Magnetic information was recorded on the above medium using a permalloy head having a gap length of 0.4111 and a winding number of 24 turns. Reproduced on a Maloy MR head, the electromagnetic conversion characteristics were examined. At this time, the flying height during recording and playback was 80 nm. As a result of the measurement, the noise at a linear recording density of 150 kFCI was 15.5 to 25 V rns . In addition, the reproduction output is 1. Tsu Oh 1 or et al. 1.4 mV P i.
  • Magnetic film composition, magnetic MakumakuAtsu, coercive force, Roh I's of the measurement result, measurement or Luo value of the required order was V ⁇ I sb of the magnetic viscosity, Remane Nsu in the range of your good beauty 20 or et al 60 ° C Table 2 shows the temperature coefficient of coercive force.
  • Magnetic film composition Magnetic film film Coercive force H c noise ⁇ -I sb (X -dH r / dT thickness,
  • Fig. 6 shows the relationship between ⁇ ⁇ Isb and the temperature coefficient of the remanence coercive force
  • Fig. 7 shows the correlation between v'Isb and noise .
  • Fig. 6 As is clear from the figure, the temperature coefficient of the remanence coercive force tends to increase as V ⁇ Isb decreases. .
  • the temperature coefficient of the remanence coercive force is calculated by using the data of the dependency of the remanence coercivity on the time of applying a magnetic field to equation (6). The remanence coercivity when the magnetic field application time is 8 seconds is subtracted from the remanence coercivity H0 when there is no influence of the thermal fluctuations obtained by the calculation. The value was divided by the absolute temperature ( ⁇ 0 - ⁇ ⁇ ) / ⁇ (however, ⁇ : 298 ⁇ ).
  • the noise decreases as V ⁇ I sb decreases as the force increases.
  • the media with V ⁇ Isb of 2.0 X 10-15 emu or less showed low noise and high S / N.
  • these media have a low coercive force of less than 20000e and low resolution.
  • the magnetic disk device similar to the embodiment has a 2 gigabit capacity. DOO / square Lee emissions recording density of the switch (room temperature) picture of La-les-over door 10 - 11 and this you in following the Tsu Oh in difficult.
  • a Cr alloy underlayer was formed on a mirror-polished disk made of an A1-Mg alloy coated with an electroless plating Ni-P, and then a CoCrPt magnetic layer was formed. And carbon protective film was formed to produce a magnetic disk.
  • the underlayer, magnetic layer, and protective layer of the Cr alloy are made of Ar gas. It was formed by the butterfly ring. At this time, the Ar pressure was set at 2.0 milliTorr. Cr-V, Cr-W, Cr-Ti, Cr-Si, and Cr-Mo were used for the underlayer of the Cr alloy, and a total of 20 samples with different underlayer compositions were prepared.
  • the thickness of the Cr alloy layer is 50 nm
  • the CoCrPt magnetic layer is 25 nm
  • the protective layer is 10 nm.
  • the Cr content of the CoCrPt magnetic layer was 15 to 23 atomic percent, and the Pt content was 8 atomic percent.
  • the coercive force H c of the medium obtained in this way was distributed in the range of 1800 to 2800 Oe.
  • the product ⁇ ⁇ I sb of the activation volume V and the spontaneous magnetization I sb is 2.01 and is distributed in the range of 3.43 10 ⁇ 15 emu, and the temperature coefficient of the remanence coercivity is ⁇ dH
  • the r / dT ranged from 4.1 to 5.9 Oe / deg.
  • the magnetic information is recorded on the above medium using a permalloy head having a gap length of 0.4 / m and a winding number of 24 turns, and the magnetic information is recorded on the permalloy MR. And the electromagnetic conversion characteristics were examined. At this time, the recording height was set at 80 nra during recording.
  • Magnetic film composition Magnetic film thickness Coercive force H c noise ⁇ ⁇ I sb (X -dH r / dT,
  • Fig. 8 shows the relationship between v'Isb and the temperature coefficient of coercive force
  • Fig. 9 shows the relationship between V • Isb and noise .
  • Fig. 8 As in the case of the embodiment, as shown in Fig. 8, the temperature coefficient of the coercive force tends to increase as V ⁇ I sb decreases, as in the embodiment. is there . Also, in this comparative example, the temperature coefficient of the coercive force is calculated by using the data of the dependency of the remanence coercive force on the application time of the magnetic field in equation (6).
  • the remanence coercivity when the magnetic field application time is 8 seconds is subtracted from the remanence coercivity Ho when there is no influence of the thermal fluctuation and the subtraction is obtained.
  • the value obtained by dividing the value by absolute temperature (H 0 -H r ) / T was not less than the value.
  • the noise decreases as V ⁇ Isb decreases as the force increases.
  • v'I sb is greater than 2.0 Xl (T 15 eniu) and the noise is higher. Therefore, the coercive force is higher.
  • the temperature coefficient of the magnetic disk device is relatively low, the magnetic disk device similar to the embodiment has an error at a recording density of 2 gigabit square inch. a record over door was Tsu Oh flame frame is a child you under 10 11 or less. possibility for interest on the industry
  • the temperature coefficient of the remanence coercive force is 7 Oe / s (deg) or more and 12 Oe / deg. / deg Ri Ah in more than under, came to have a Les Mas of when the influence of NetsuYura et al technique is not the name value down scan coercive force ⁇ ⁇ , the ⁇ have absolute temperature records while the value down scan the coercive force ⁇ , If the temperature coefficient is 1.7 X ⁇
  • a ferromagnetic metal thin film of (H.-I H r ) / T ⁇ or less the medium noise during reproduction is reduced and the temperature coefficient of the coercive force of the magnetic medium is reduced.
  • the operating temperature from 0 to 60 is possible. It enables high-density recording of 2 gigabits square inch or more that can withstand high speeds, and is suitable as a means for realizing high-density magnetic disk devices.

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Abstract

A ferromagnetic metal thin film whose remanence coercive force has a temperature coefficient of 7 Oe/deg. - 12 Oe/deg. and has a temperature coefficient not larger than 1.7 x {(Ho - Hr)/T} (where Ho denotes the remanence coercive force when the influence of thermal fluctuation does not exist, Hr denotes the remanence coercive force and T denotes the absolute temperature) is used to reduce the medium noise at the time of reproduction and to suppress the temperature coefficient of the coercive force of a magnetic medium. A recording head whose magnetic pole is partially composed of the ferromagnetic metal thin film and a reproducing head in which a magnetoresistance effect device is used are combined to provide a magnetic disc apparatus which has a recording density not lower than 2 Gbit/in2 and can withstand an operation temperature of 0 - 60 °C.

Description

W  W
明 細 書 磁気記録媒体お よ び磁気記録再生装置 技術分野 Description Magnetic recording media and magnetic recording / reproducing devices
本発明 は、 強磁性金属薄膜磁気記録媒体に係わ り 、 特 に 、 電磁変換特性に優れた磁気記録媒体お よ ぴ大容 量の磁気記録再生装置 に 関す る 。 背景技術  The present invention relates to a ferromagnetic metal thin film magnetic recording medium, and in particular, to a magnetic recording medium having excellent electromagnetic conversion characteristics and a large-capacity magnetic recording / reproducing apparatus. Background art
強磁性金属薄膜磁気記録媒体の記録密度の 向上、 高 10 出力化、 低 ノ イ ズ化 に は結晶粒子 の微細化が不可欠で あ る 。 た と え ば、 従来 よ り 検討 さ れて き た Co- Cr- Ta、 Co- Cr-Pt系媒体では微細化が進み、 現在で は粒径が 30 nm内外の も の が実用化 さ れて い る 。  In order to increase the recording density, increase the output power, and reduce the noise of a ferromagnetic metal thin-film magnetic recording medium, miniaturization of crystal grains is essential. For example, Co-Cr-Ta and Co-Cr-Pt media, which have been studied in the past, have been miniaturized, and those with a particle size of 30 nm or outside are now in practical use. ing .
と こ ろ で、 強磁性結晶粒子が微細 で も 、 結晶粒子間 15 の相互作用 が強い場合に は、 複数の粒子が一団 と な つ て磁化反転 して記録 さ れ る よ う に な る 。 こ の よ う に 、 複数の粒子が一団 と な っ て磁化反転 し 、 磁化反転単位 が大き く な る と 、 個 々 の結晶粒が小 さ く て も 、 再生時 の ノ イ ズが増す。 こ の た め 、 高密度化の大 き な障害 に 20 な る 。  At this point, even if the ferromagnetic crystal grains are fine, if the interaction between the crystal grains 15 is strong, a plurality of grains will be recorded as a group with the magnetization reversal. As described above, when a plurality of particles undergo a magnetization reversal as a group and the unit of magnetization reversal increases, the noise during reproduction increases even if the individual crystal grains are small. This is a major obstacle to densification.
磁化反転単位の大 き さ は、 磁気粘性 と 関連が あ る 。 すな わ ち 、 磁気粘性の揺 ら ぎ場が 大 き い ほ ど磁化反転 単位は小 さ い と 考 え ら れて い る 。 The size of the magnetization reversal unit is related to the magnetic viscosity. In other words, the larger the magnetic viscous fluctuation field, the greater the magnetization reversal. The unit is considered small.
磁気粘性の揺 ら ぎ場の意味について は、 ジ ャ ーナル ォプ フ イ ジ イ ク ス エ フ ： メ タ ノレ フ イ ジ イ ク ス ( Journal of Physics F： Metal Physics) 14卷 L155 〜 L159頁 （ 1984年発行） に記載 さ れて い る 。 さ ら に 、 詳細 な測定条件 につい て は、 ジ ャ ー ナル ォブ マ グ ネ テ イ ズム エ ン ド マ グネ テ イ ク マ タ ー リ アノレズ For the meaning of the magnetic viscous fluctuation field, see Journal of Physics F: Metal Physics, Vol. 14, pages L155-L159. (Issued in 1984). For more detailed measurement conditions, refer to the Journal of Magnetism
( Journal of Magnetism and Magnetic Materials) 127卷 233 ~ 240 ( 1993年発行） 、 同 145卷 255〜 260 ( 19 95年発行） お よ ぴ同 152卷 411〜 416 ( 1996年発行） に 記載 さ れて い る 。 (Journal of Magnetism and Magnetic Materials) Vol. 127, 233-240 (published in 1993), Vol. 145, 255-260 (published in 1995), and Vol. 152, 411-416 (published in 1996) Yes.
以下 において 、 磁気粘性の揺 ら ぎ場の測定原理 を説 明す る 。  In the following, the principle of measurement of the magnetic viscous fluctuation field will be described.
磁性材料に新た な磁場 を 印加す る と 、 磁化 I ( t )は磁 場印加時間 の対数 In t に対 し て 、  When a new magnetic field is applied to the magnetic material, the magnetization I (t) changes with respect to the logarithm of the magnetic field application time, In t,
I (t) = const. ~ S · In t ( 1 ) の 関係 で変化す る 場合が 多い。 こ こ で 、 I ( t )は単位体 積 あ た り の磁気モー メ ン ト で あ り 、 tは新た な磁場を 印加 し た後 の経過時間 で あ る 。 粘性係数 S は磁場を正 方向 に シ フ ト し て 印力 tl し た と き に は正、 負 に シ フ ト し た と き に は負 の値を持つ。 ま た 、 S は非可逆磁化率 % irrと 揺 ら ぎ場 と の積で表 さ れ る こ と が知 ら れて い る 。 すな わ ち 、 I (t) = const. ~ S · Int (1) It often changes. Here, I (t) is the magnetic moment per unit volume, and t is the elapsed time after applying a new magnetic field. The viscosity coefficient S has a positive value when the magnetic field is shifted in the positive direction and the printing force is tl, and a negative value when the magnetic field is shifted to the negative direction. It is also known that S is represented by the product of the irreversible susceptibility% irr and the fluctuation field. That is,
S = % irr · Hf ( 2 ) が成立す る 。 し た が っ て 、 実験力 ら S お よ ぴ を ％ irrを 求 めれば、 揺 ら ぎ場が求ま る 。 揺 ら ぎ場は熱揺 ら ぎの 影響の大小 を示す量で あ り 、 揺 ら ぎ場が大 き い こ と は 熱揺 ら ぎの影響 を受 けやす く 、 磁化反転単位が小 さ い こ と を意味す る 。 S =% irr · H f ( 2) Holds. Therefore, if S and Y are obtained from the experimental force and% irr is obtained, a fluctuation field can be obtained. The fluctuation field is an amount that indicates the magnitude of the effect of the thermal fluctuation.A large fluctuation field is susceptible to the thermal fluctuation and a small unit of magnetization reversal. Means.
磁界強度が保磁力 Hcな い し は レ マ ネ ンス 保磁力 （残 留磁化がゼ ロ に な る 保磁力 ） Hrに等 し い と こ ろ での揺 ら ぎ場は、 保磁力 な い し は レ マ ネ ンス 保磁力 の磁場印 加時間依存性か ら も 求 め る こ と が で き る 。 保磁力 な い し は レマネ ンス保磁力 は 、 磁場印加時間 t と と も に 、 Yura et al. Technical field of the magnetic field strength in a furnace come when not to, such as the coercive force H is Shi had a c-les while the value Nsu coercive force (coercivity residual magnetization ing to zero) H r is, coercive force It can also be obtained from the dependence of the remanence coercivity on the magnetic field application time. The coercive force or the remanence coercive force, together with the magnetic field application time t,
Hc (又 は Hr) = — Β · In t + const. ( 3 ) の 関係で印加時間 と と も に低下す る 場合が 多い。 本明 細書に記載 し た試料で は 、 すべて式 （ 3 ) の 関係が成 立 した。 た だ し 、 磁場印加時間 は 8 秒カゝ ら 30分 と し た 。 式 （ 3 ) に し た が っ て保磁力 ない し は レマ ネ ンス 保 磁力 が磁場印加時間 t と と も に変化す る 場合、 Bは磁 界強度が保磁力 ない し は レマ ネ ンス 保磁力 に等 しい と こ ろ で の揺 ら ぎ場 Hf と ほ と ん ど 同 じ値を示す。 こ の方 法は、 簡便かつ再現性が よ い。 H c (or H r ) = — Β · Int + const. (3) In many cases, it decreases with the application time. In the samples described in this specification, the relationship of the formula (3) was established. However, the time for applying the magnetic field was set to 8 seconds to 30 minutes. If coercivity or remanence varies according to magnetic field application time t according to equation (3), B indicates coercivity or remanence coercivity in magnetic field strength etc. does O coercive and swinging, et al Technical field H f of an equal arbitrariness and this filtered to show the same value. This method is simple and has good reproducibility.
そ こ で、 本発明 では Bの値 を磁気の揺 ら ぎ場 と し た Therefore, in the present invention, the value of B is used as a magnetic fluctuation field.
。 すな わ ち 、 . That is,
H„ (又は Hr) = -Hf - In t + const. ( 4 ) 揺 ら ぎ場 Hfが求ま る と 、 H „(or H r ) = -H f -Int + const. (4) Once the fluctuation field H f is found,
V · b=kT/Hf ( 5 ) に従い、 活性化体積 V が求ま る （ ジ ャ ー ナル ォブ フ イ ジ イ ク ス エ フ ： メ タ ル フ イ ジ イ ク ス （ Journa 1 of Physics F： Metal Physics) 14卷 L 155〜し 159頁 ( 1984年発行） ) 。 なお、 式 （ 5 ) におい て 、 kは Bol tzmann定数、 Tは絶対温度 、 Isbは磁性膜 中 の磁性 を持 つ た部分の 自 発磁化で あ る 。 Vb = kT / H f (5) The activation volume V is obtained according to (Journa 1 of Physics F: Metal Physics) 14 vol. L155 ~ 159 pages (issued in 1984). In equation (5), k is the Boltzmann constant, T is the absolute temperature, and I sb is the spontaneous magnetization of the magnetic part in the magnetic film.
活性化体積 V と 自 発磁化 Isbと の積 V · Isbは磁化反 転単位の大 き さ を表 し 、 発 明者 ら に よ り 、 v * Isbが 小 さ い ほ ど媒体 ノ イ ズが低い こ と が 明 ら 力、 に な っ た （ ジ ャ ー ナル ォ ブ マ グネ テ イ ズ ム エ ン ド マ グネ テ イ ク マ タ ー リ ア ノレ ズ ( Journal of Magnetism andThe product V · I sb of the activation volume V and the spontaneous magnetization I sb represents the size of the unit of magnetization reversal. According to the inventors, the smaller v * I sb is, the smaller the medium It was clear that the noise was low (Journal of Magnetism and End Magnetism).
Magnetic Materials) 145卷 255〜 260 ( 1995年発行 ) お よ び同 152卷 411〜 416 ( 1996年発行） ) 。 Magnetic Materials) Vol. 145, 255-260 (published in 1995) and Vol. 152, 411-416 (published in 1996).
式 （ 4 ) は測定磁場印加時間 の範囲 が 比較的狭い場 合に成立す る 。 実際の書き 込み （パ ル ス 印加時間 ： 〜 10 8秒）か ら保存 （ 10年 ： 〜 108 秒） に至 る 広い範囲 で は 、 Equation (4) holds when the range of the application time of the measurement magnetic field is relatively narrow. Actual write (Pulse application time: ~ 10 8 seconds) or, et al. Storage: In a broad range Ru optimal (10 years to 10 8 seconds),
Hc (又 は Hr) H c (or H r )
= H0 { 1- [ Cln ( At/0.693) ] 1/2} ( 6 ) の方が実測値 と 良 く 一致す る （ア イ イ一ィ ーィ一 ト ラ ン ザ ク シ ヨ ン ズ オ ン マ グネ テ イ ク ス マ グ （ IE EE TRANSACTIONS ON MAGNETICS MAG) - 20卷 754〜756 ( 1994年発行） ）。 こ こ で 、 H0は熱揺 ら ぎの影響が な い場合の保磁力 、 C は フ ィ ッ テ ィ ン グパ ラ メ ー タ で あ る 。 さ ら に A はス ピ ン歳差運動 の周 波数で 109/sの値 が と ら れ る 。 = H 0 {1- [Cln (At / 0.693)] 1/2 } (6) is in good agreement with the measured value (II-transactions) IE EE TRANSACTIONS ON MAGNETICS MAG-20 vol. 754-756 (issued in 1994). Here, H 0 is a coercive force when there is no influence of thermal fluctuation, and C is a fitting parameter. . Is found in the A value of 10 9 / s in the frequency of the scan pin precession DOO et is Ru.
磁場印加時間 を 8 秒か ら 30分 と し て得 ら れた保磁力 ない し は レマネ ンス保磁力 の磁場印加時間依存性のデ 一タ を式 （ 6 ) に フ ィ ッ テ ィ ン グす る と 、 熱揺 ら ぎ の 影響が ない場合の保磁力 Hoお よ び C が 求ま る 。  The coercive force obtained when the magnetic field application time is set to 8 seconds to 30 minutes or the data of the magnetic field application time dependence of the remanence coercivity is fitted to equation (6). Then, the coercive forces Ho and C in the case where there is no influence of the thermal fluctuation are obtained.
従来法 に従 っ て 、 無電解 メ ツ キ の Ni-Pで被覆 し た A1 - M g合金か ら な る 鏡面研磨 し た 円板上 に Cr下地層 を形成 し 、 ついで CoCrTa磁性層 、 さ ら に カ ー ボ ン保護膜 を形 成 し て磁気デ ィ ス ク を作製 し た。 Cr下地層 、 磁性層 、 保護膜は と も に Arガ ス を用 い た ス パ ッ タ リ ン グで形成 した。 こ の際、 基板温度 は 300°C、 Ar圧力 は 2. 0ミ リ To rrと した。 Cr下地層 の厚 さ は 50nm、 磁 性層 は 25nm、 保護膜は 10nmで あ る 。 CoCrTa磁性層 の組成は原子％ で表 し、 C 0 ： 80 %、 C r ： 16 %、 T a ： 4 % で あ る 。 こ の 組成 を以下本明細書では CoCr16Ta4の よ う に表す。 こ の 媒体の レマネ ンス保磁力 Hrは 2430 Oeで あ っ た。 ま た 、 レマネ ンス 保磁力 と 等 し い磁界強度での 25 °Cで の活 性化体積 V と 自 発 磁化 Isbと の積 ν · Isbの値は 1. 75 X 10— 15 emuで あ っ た。 さ ら に 、 20。C か ら 60。Cで測定 し た レマネ ンス 保磁力 の温度係数 - dHr/dTは 7. 96 Oe/degで あ っ た。 According to the conventional method, a Cr underlayer is formed on a mirror-polished disk made of an A1-Mg alloy coated with an electroless plating Ni-P, and then a CoCrTa magnetic layer is formed. In addition, a magnetic disk was fabricated by forming a carbon protective film. The Cr underlayer, magnetic layer, and protective film were all formed by sputtering using Ar gas. At this time, the substrate temperature was 300 ° C, and the Ar pressure was 2.0 milliTorr. The thickness of the Cr underlayer is 50 nm, the thickness of the magnetic layer is 25 nm, and the thickness of the protective film is 10 nm. The composition of the CoCrTa magnetic layer is represented by atomic%, and is C0: 80%, Cr: 16%, and Ta: 4%. This composition is hereinafter referred to as CoCr 16 Ta 4 in this specification. The remanence coercive force H r of this medium was 2430 Oe. Also, the value of the product [nu · I sb and vitalize the volume V and the spontaneous magnetization I sb in = 25 ° C in at magnetic field strength has to equal the Remane Nsu coercive force at 1. 75 X 10- 15 emu there were. In addition, 20. C to 60. Temperature coefficient of Remane Nsu coercive force was measured by C - dH r / dT was Tsu Oh at 7. 96 Oe / deg.
上記媒体に 、 ギ ャ ッ プ長が 0. 4 《1人 卷線数が 24タ ー ン のパー マ ロ イ へ ッ ド を用 いて磁気情報 を記録 し 、 パ 一マ ロ ィ 磁気抵抗へ ッ ド を用 い て 再生 し て電磁変換特 性 を調べた。 こ の際、 記録お よ び再生時の浮上高 さ は 80 n mと し た The magnetic information is recorded on the above medium using a permalloy head having a gap length of 0.4 《24 turns per person, The reproduction was performed using a 1-malloy magnetoresistive head, and the electromagnetic conversion characteristics were examined. At this time, the flying height during recording and playback was 80 nm.
こ の媒体を用 い る と 1 ギガ ビ ッ ト 平方ィ ン チ の記 録密度 を有す る 磁気デ ィ ス ク 装置 を作製で き た 力 S、 2 ギ ガ ビ ッ ト 平方ィ ン チ以上 の記録密度 を有す る 実用 に耐 え る 磁気デ ィ ス ク 装置 は作製で き な か っ た。 そ の 原因 は媒体 ノ イ ズが大 き く かつ保磁力 の温度係数が 大 き い た め で め っ た 。  Using this medium, a magnetic disk device with a recording density of 1 gigabit square inch could be manufactured. Force S, 2 gigabit square inch or more A practical magnetic disk device with a recording density of the above could not be manufactured. This was due to the large noise of the medium and the large temperature coefficient of the coercive force.
本発明 の 目 的 は、 再生時の ノ イ ズを低減す る と と も に 、 保磁力 の温度係数 を低 く 抑 え 、 0 か ら 60 °C の使用 温度 に耐え る 2 ギガ ビ ッ ト 平方イ ンチ以上の記録密 度 を有す る 磁気記録媒体お よ び磁気デ ィ ス ク 装置 を提 供す る こ と に あ る 。 発明 の 開示  The purpose of the present invention is to reduce the noise during reproduction, suppress the temperature coefficient of coercive force to a low value, and withstand a 2 gigabit operating temperature of 0 to 60 ° C. An object of the present invention is to provide a magnetic recording medium and a magnetic disk device having a recording density of at least a square inch. Disclosure of invention
上記 目 的 を達成す る た め の基本構成を以下 に示す。 図 1 は、 本発明 に よ る 磁気記録媒体の拡大断面図 で あ る 。 図 1 で、 1 は Ni- Pを被着 した アル ミ ニ ウ ム 一 マ グネ シ ゥ ム合金、 ガ ラ ス 、 カ ー ボ ン等の非磁性基板で あ る 。 2 は磁性膜の結晶方向 お よ び結晶粒子サイ ズを 制御す る た め の非磁性下地層 で、 Cr、 Cr- Mo、 Cr-W、 C r-Ti、 Cr-Vな ど の金属層 力 ら な る 。 3 は Co-Cr-Ta, Co -Cr-Ta-Ni, Co-Cr-Pt, C o - C r一 P t - T a、 Co - 0、 Co - Ni、 Co P T/JP97 The basic configuration to achieve the above objective is shown below. FIG. 1 is an enlarged sectional view of a magnetic recording medium according to the present invention. In FIG. 1, reference numeral 1 denotes a non-magnetic substrate made of aluminum-magnesium alloy, glass, carbon, or the like on which Ni-P is adhered. 2 is a non-magnetic underlayer for controlling the crystal orientation and crystal grain size of the magnetic film, and is a metal layer such as Cr, Cr-Mo, Cr-W, Cr-Ti, Cr-V, etc. Help. 3 is Co-Cr-Ta, Co-Cr-Ta-Ni, Co-Cr-Pt, Co-Cr-Pt-Ta, Co-0, Co-Ni, Co PT / JP97
_Cr、 Co-Mo , Co一 Ta、 Co一 Ni一 Cr、 Co一 Ni 25— 0等 の ノ ル ト を 主成分 と す る 強磁性薄膜 で あ る 。 4 は保護 潤 滑 層 で 、 炭 素膜 、 酸化膜 、 プ ラ ズ マ 重 合膜 、 脂肪酸 、 パ 一 フ ル ォ ロ カ ル ボ ン 酸 、 パ ー フ ル ォ ロ ポ リ エ ー テ ル等 を 単独 な い し は複合体 と し て 用 い る こ と が で き る 。 _Cr, Co-Mo, Co-Ta, Co-Ni-Cr, Co-Ni 25-0 A ferromagnetic thin film mainly composed of knots. 4 is a protective lubricating layer, such as carbon film, oxide film, plasma polymer film, fatty acid, perfluorocarboxylic acid, perfluoropolyether, and the like. Can be used alone or as a complex.
磁性層 3 に は 、 保磁力 の 温度係 数 が 7 Oe/deg以 上 、 12 Oe/deg以 下 で あ り 、 熱揺 ら ぎ の 影響 が な い 場合 の レ マ ネ ン ス 保磁力 を H0、 レ マ ネ ン ス 保磁力 を Hr、 絶 対 温度 を T と し た と き 、 温度係 数 が 1.7 X { ( H0- ΗΓ ) / Τ } 以 下 で あ り 、 保磁力 が 2000 Oe以 上 で あ る 強 磁性薄膜 を 用 い 、 磁性層 の 厚 さ は 5nm以 上 、 30nm以 下 と す る の が 望 ま し い 。 The magnetic layer 3 has a temperature coefficient of coercive force of 7 Oe / deg or more and 12 Oe / deg or less, and has a remanence coercive force of H when there is no influence of thermal fluctuation. 0 , when the remanence coercive force is H r and the absolute temperature is T, the temperature coefficient is 1.7 X {(H 0- Γ Γ ) / /} and the coercive force is A ferromagnetic thin film of 2000 Oe or more is used, and the thickness of the magnetic layer is desirably 5 nm or more and 30 nm or less.
強磁性薄膜 は Cr、 Ta、 Pt、 Ni、 Mo、 V、 Ti、 Zr、 Hf 、 Si、 W、 0か ら な る 群 の す く な く と も 一種 を 含 む コ バ ノレ ト 基磁性合金薄膜 、 例 え は * Co— Cr一 Ta， Co_Cr— Ta— Ni， Co-Cr-Pt , Co-Cr-Pt-Ta, Co - 0、 Co - Ni、 Co - Cr、 Co-Mo 、 Co_Ta、 Co— Ni— Crゝ Co— Ni— 0等 の コ ノ /レ 卜 を 含 有す る 薄膜 で あ る こ と が 望 ま し い 。  The ferromagnetic thin film is a covanolate-based magnetic alloy containing at least one of the group consisting of Cr, Ta, Pt, Ni, Mo, V, Ti, Zr, Hf, Si, W, and zero. Thin films, such as * Co-Cr-Ta, Co_Cr-Ta-Ni, Co-Cr-Pt, Co-Cr-Pt-Ta, Co-0, Co-Ni, Co-Cr, Co-Mo, Co_Ta, It is desirable that the film be a thin film containing Co / Ni—0, such as Co—Ni—Cr—Co—Ni—0.
本発 明 に お け る 保磁力 Hcな い し は レ マ ネ ン ス 保磁力 Hrと 等 し い磁界 強度 で の 活性化 体積 V と 自 発 磁化 Isb と の 積 ν · Isbお よ び熱揺 ら ぎ の 影響 が な い 場合 の レ マ ネ ン ス 保磁力 Η0の 具体 的 測 定方法 は 、 以 下 の 通 り で あ る 。 That only in this onset Ming Shi have coercive force H c is your product ν · I sb of the record while the value down the scan coercivity H r and the activation volume V and the spontaneous magnetization I sb of an equal and have the magnetic field strength good beauty Les while the value down scan specific measurement method of the coercive force Η 0 of when the influence of NetsuYura et al technique is not name, Ru Oh the Ri through the following.
揺 ら ぎ場 Hf を 求 め る た め 、 磁気 デ ィ ス ク カゝ ら 切 り 出 した 7 mm角 の試料片 に 一 10， 000 Oeの磁場を 印加 し て 直流消磁 した の ち 、 保磁力 ない し は レマ ネ ン ス 保磁力 よ り も わずかに低い正 の磁場 を印加 し 、 磁化 ない し は 残留磁化がゼ ロ に な る ま での 時間 t を求 め る 。 To obtain the fluctuation field H f , cut out from the magnetic disk After applying a magnetic field of 10,000 Oe to apply a magnetic field of 10,000 Oe to the 7 mm square specimen and applying a magnetic field, the coercive force or a positive magnetic field slightly lower than the remanence coercive force was applied. Otherwise, the time t until the remanent magnetization becomes zero is determined.
こ の操作を直流消磁後 に 印加す る 正 の磁場 を少 しず つ低 く して繰 り 返す。 こ う し て 求 め た保磁力 ない し は レ マ ネ ン ス 保磁力 の磁場印加時間依存性か ら 式 （ 4 ) に し た が っ て揺 ら ぎ場 H f の値が求ま り 、 式 （ 5 ) 力 > ら 活性化体積 V と 自 発磁化 Isbと の積 ν · Isbが 求 ま る 。 This operation is repeated while the positive magnetic field applied after DC demagnetization is gradually reduced. The value of the fluctuation field H f can be obtained from the dependence of the coercive force thus obtained on the magnetic field application time of the remanence coercive force according to equation (4). equation (5) force> product [nu · I sb with al the activation volume V and spontaneous magnetization I sb is Ru determined or.
ま た 、 求 め た保磁力 な い し は レマネ ンス 保磁力 の磁 場印加時間依存性か ら 式 （ 6 ) に従 っ て 、 熱揺 ら ぎの 影響の な い場合の保磁力 H0を 求 め る こ と が で き る 。 保 磁力 の磁場印加時間依存性か ら 求 め た揺 ら ぎ場は 、 レ マネ ンス保磁力 の磁場印加時間依存性か ら 求 め た揺 ら ぎ場 と ほ と ん ど 同 じ値 を示す。 測定が容易 で あ る こ と 力、 ら 、 本発 明 において は レマネ ン ス 保磁力 の磁場印加 時間依存性か ら 揺 ら ぎ場を求 め た。 測定は D M S ( D i gital Measurement Systems) 社製の振動型磁力計を 用 いて行い 、 測定温度 は 25 ± 3 °C 、 直流消磁後 の磁場 印加時間 は 8 秒カゝ ら 30分 と し た。 ま た 、 保磁力 H cは通 常の ヒ ス テ リ シ ス の測定に よ っ て 求 め た。 他方、 レ マ ネ ンス保磁力 Ητは磁場印加時間 を 8秒 と し た場合の値 と した。 さ ら に 、 Hrの温度係数 （ - dHr/dT) は 20〜 60 °C の間 で測定 した Hrの温度変化の勾配カゝ ら 求 め た。 レマネ ンス 保磁力 の温度係数が 7 Oe/deg以上、 12 Oe/deg以下で あ り 、 熱揺 ら ぎ の影響が ない場合の レ マ ネ ン ス 保磁力 を H0, レ マ ネ ン ス 保磁力 を Hr、 絶対温 度 を T と し た と き 、 温度係数が 1.7 X { ( H0- Hr) / T } 以下で あ る 強磁性薄膜を用 い る こ と に よ り 、 保磁 力 の温度係数を適切 に抑 え る と と も に 、 媒体の S / N を高 く す る こ と が 出来 る 。 In addition, the obtained coercive force or the coercive force H 0 in the case where there is no influence of thermal fluctuation is obtained from the dependency of the remanence coercive force on the magnetic field application time according to equation (6). You can do it. The fluctuation field obtained from the dependence of the coercivity on the magnetic field application time shows almost the same value as the fluctuation field obtained from the dependence of the remanence coercivity on the magnetic field application time. In addition, in the present invention, the fluctuation field was determined from the dependence of the remanence coercivity on the magnetic field application time. The measurement was performed using a vibrating magnetometer manufactured by DMS (Digital Measurement Systems), the measurement temperature was 25 ± 3 ° C, and the time for applying a magnetic field after DC degaussing was 8 seconds to 30 minutes. In addition, the coercive force Hc was obtained by a normal hysteresis measurement. On the other hand, the remanence coercive force τ τ was a value when the magnetic field application time was 8 seconds. Et al., Temperature coefficient of H r (- dH r / dT ) was gradient mosquitoゝMotomu Luo because the temperature change of H r measured between. 20 to 60 ° C. When the temperature coefficient of the remanence coercive force is 7 Oe / deg or more and 12 Oe / deg or less, the remanence coercive force is H 0 when there is no effect of thermal fluctuation, and the remanence coercivity is H. Assuming that the magnetic force is H r and the absolute temperature is T, the use of a ferromagnetic thin film having a temperature coefficient of 1.7 X {(H 0 -H r ) / T} or less will help The S / N of the medium can be increased while appropriately controlling the temperature coefficient of the magnetic force.
磁極の一部 に金属磁性膜を用 い た記録へ ッ ド と 、 磁 気抵抗効果素子 を用 い た再生へ ッ ド と 組み合わせ る こ と に よ り 、 急峻に記録で き る 媒体の性能 を 引 き 出せ る の で 2 ギガ ビ ッ ト Ζ平方イ ン チ以上の高密度記録再生 装置 を提供す る こ と が 出来 る 。  By combining a recording head using a metal magnetic film for part of the magnetic pole with a reproducing head using a magnetoresistive element, the performance of a medium capable of recording steeply can be improved. Since it can be pulled out, a high-density recording / reproducing apparatus of 2 gigabits / square inch or more can be provided.
図面の簡 単な説明 Brief description of the drawings
図 1 は、 本発明 の強磁性金属磁性薄膜媒体の基本構 造を示す図 で あ り 、 図 2 は 、 活性化体積 V と 自 発磁化 Isbと の積 V · Isbと レマネ ンス 保磁力 の温度係数 - dHr/d Tと の相 関図 で あ り 、 図 3 は、 活性化体積 V と 自 発磁 化 Isbと の積 v ' Isbと ノ イ ズ と の相 関 図 で あ り 、 図 4 は、 磁気ヘ ッ ド の構造図 で あ り 、 図 5 は、 磁気デ ィ ス ク 装置の構造図 で あ り 、 図 6 は、 活性化体積 V と 自 発 磁化 Isbと の積 ν · Isbと レマ ネ ン ス 保磁力 の温度係数 - dHr/dTと の相 関図 で あ り 、 図 7 は、 活性化体積 V と 自 発磁化 Isbと の積 ν · Isbと ノ ィ ズ と の相 関図 で あ り 、 図 8 は、 活性化体積 V と 自 発磁化 Isbと の積 ν · Isbと レマネ ンス保磁力 の温度係数 - dHr/dTと の相 関図 で あ り 、 図 9 は、 活性化体積 V と 自 発磁化 Isbと の積 ν · Ι bと ノ イ ズ と の相 関図 で あ る 。 発 明 を 実施す る た め の最 良 の形態 FIG. 1 is a diagram showing a basic structure of the ferromagnetic metal magnetic thin film medium of the present invention, and FIG. 2 is a diagram showing a product V · I sb of an activation volume V and spontaneous magnetization I sb and a remanence coercive force. temperature coefficient of - Ri Ah in phase Sekizu with dH r / d T, FIG. 3 is a correlation diagram of the product v 'I sb and Bruno size b of the activation volume V and the own Hatsu磁of I sb FIG. 4 is a structural diagram of the magnetic head, FIG. 5 is a structural diagram of the magnetic disk device, and FIG. 6 is a diagram showing the activation volume V and the spontaneous magnetization Isb . FIG. 7 is a correlation diagram between the product ν · I sb and the temperature coefficient of the coercivity of the remanence -dH r / dT. FIG. 8 is a correlation diagram between the product ν · I sb of the magnetization I sb and the noise, and FIG. 8 shows the product ν · I sb of the activation volume V and the spontaneous magnetization I sb and the remanence coercive force. Fig. 9 shows the correlation between the noise ν and Ιb of the activation volume V and the spontaneous magnetization I sb, and the noise with the temperature coefficient-dH r / dT of . Best mode for carrying out the invention
以下 に 、 本発明 の 内容 を 実施例お よ び比較例 に よ つ て詳細 に説明す る 。  Hereinafter, the content of the present invention will be described in detail with reference to Examples and Comparative Examples.
[実施例 ] [Example ]
無電解 メ ッ キ の Ni- Pで被覆 し た Al-Mg合金カゝ ら な る 鏡面研磨 した 円 板上 に Cr合金下地層 を形成 し 、 ついで CoCrPtない し は CoCrPtTi磁性層 、 さ ら に カ ー ボ ン保護 膜を形成 し て磁気デ ィ ス ク を作製 し た。  An underlayer of Cr alloy is formed on a mirror-polished disk made of Al-Mg alloy coated with Ni-P of electroless plating, and then a CoCrPt or CoCrPtTi magnetic layer is formed. A magnetic disk was fabricated by forming a carbon protective film.
Cr合金下地膜、 磁性層 、 保護膜は と も に Arガ ス を用 いた ス パ ッ タ リ ン グ で形成 し た。 こ の 際、 Ar圧力 は 2 .0ミ リ Torrと した。 下地層 に は Crの他 に 、 Cr- V、 Cr - W 、 Cr- Ti、 Cr- Siない し は Cr-Mo合金 を 単層 な い し は異 種の金属層 か ら な る 2 層 と し て用 い 、 下地組成の異な る 試料を合計 43個用意 し た。 Cr合金層 の総膜厚は 20か ら 50nm、 CoCrPtない し は CoCrPtTi磁性層 は 3 力、 ら 30η m 、 保護層 は 10nmで あ る 。 CoCrPt磁性層 の Cr含量は 19力 ら 22原子パーセ ン ト 、 Pt含量は 4 か ら 10原子パーセ ン ト と した。 CoCrPtTi磁性層 に は CoCr20Pt10Ti4な い し は CoCr20Pt8Ti4を 使 用 し た 。 こ れ ら の 磁 性 層 の Cr含 量 は後 述 の 比較例 1 お よ び 2 よ り も 多 く な つ て い る 。 The Cr alloy underlayer, magnetic layer, and protective film were all formed by sputtering using Ar gas. At this time, the Ar pressure was set at 2.0 milliTorr. In addition to Cr, the underlayer has two layers consisting of a single layer of Cr-V, Cr-W, Cr-Ti, Cr-Si or Cr-Mo alloy or a layer of a different kind of metal. For this purpose, a total of 43 samples having different base composition were prepared. The total thickness of the Cr alloy layer is 20 to 50 nm, the thickness of the CoCrPt or CoCrPtTi magnetic layer is 3 to 30 ηm, and the thickness of the protective layer is 10 nm. The Cr content of the CoCrPt magnetic layer was set at 22 to 20 atomic percent, and the Pt content was set at 4 to 10 atomic percent. The CoCrPtTi magnetic layer contains CoCr 20 Pt 10 Ti 4 or CoCr 20 Pt 8 Ti 4 was used. The Cr content of these magnetic layers is larger than those of Comparative Examples 1 and 2 described later.
こ う し て 得 ら れ た 媒体 の保磁力 Hcは 1400か ら 2800 0 eの 範 囲 に 分布 し た 。 ま た 、 活性化 体積 V と 自 発磁化 I sbと の積 ν · Isbは 0. 60か ら 3. 67 X l(T15emuの 範 囲 に 分 布 し 、 レ マ ネ ン ス 保磁力 の 温度係数 -dHf/dTは 3. 7か ら 14. 2 Oe/degの 範囲 に 分布 し た 。 The coercive force H c of the obtained medium was distributed in the range of 1400 to 28000 e. In addition, the product ν · I sb between the subject and the activation volume V issued magnetization I s b is the distribution in the range of 0.60 or et al 3. 67 X l (T 15 emu , Les while the value down the scan coercive The temperature coefficient of magnetic force -dHf / dT ranged from 3.7 to 14.2 Oe / deg.
上記媒体 に 、 ギ ャ ッ プ長 が 0. 4 /z m、 卷 き 線数 24タ ー ン の ノ 一マ ロ イ へ ッ ド を 用 い て 磁気 情 報 を 記録 し 、 パ 一マ ロ イ MRへ ッ ド で 再 生 し て 電磁 変 換特性 を 調 べ た 。 こ の 際 、 記録お ょ ぴ再 生 時 の 浮 上 高 さ は 80nraと し た 。 測 定 し た 結果 、 線記録密 度 150kFCIで の ノ ィ ズ は 8 か ら 31 μ Vrmsで あ っ た 。 ま た 、 再 生 出 力 は 0. 5か ら 1. 45 m Vp_pで あ っ た 。 磁性膜組成 、 磁性膜膜厚 、 保磁力 、 ノ ィ ズ の 測 定結果 、 磁気粘性 の 測 定 か ら 求 め た V · I s bの 値 、 お よ び 20か ら 60 °C の 範 囲 で の レ マ ネ ン ス 保磁力 の 温度係数 を 表 1 に ま と め て 示す。 The magnetic information was recorded on the above medium using a No. 1 head having a gap length of 0.4 / zm and a winding number of 24 turns, and the No. The head was reproduced with a head and the electromagnetic conversion characteristics were examined. At this time, the recording height was set at 80 nra during recording. As a result of the measurement, the noise at a linear recording density of 150 kFCI was 8 to 31 μV rms . In addition, re-raw output was Tsu Oh in 0.5 or et al. 1. 45 m V p _ p. Magnetic film composition, magnetic MakumakuAtsu, the coercive force, Roh of I's measurement results, measurement or Motomu Luo because was the value of V · I sb of the magnetic viscosity, in the range of your good beauty 20 or 60 ° C, et al. Table 1 summarizes the temperature coefficient of the remanence coercive force of the above.
1 1
磁性膜組成 磁性膜膜 保磁力 Hc ノイズ v · Isb ( X - dHr/dT Magnetic film composition Magnetic film film Coercive force H c noise v · I s b (X-dH r / dT
厚 (nm) (Oe) ( vrBS) 10 15emu) (Oe/deg)Thickness (nm) (Oe) (v rBS ) 10 15 emu) (Oe / deg)
CoCr19Pt8 30 1800 31 3. 67 4. 1CoCr 19 Pt 8 30 1800 31 3.67 4.1
CoCr19Pt8 30 1890 29. 6 3. 52 4. 2CoCr 19 Pt 8 30 1890 29.6 3.52 4.2
CoCr19Pt8 30 1820 19. 6 2. 73 4. 6CoCr 19 Pt 8 30 1820 19.6 2.73 4.6
CoCr19Pt8 30 1850 21. 9 2. 66 4. 8CoCr 19 Pt 8 30 1850 21. 9 2.66 4.8
CoCr19Pt8 30 1920 21. 9 2. 60 5. 2CoCr 19 Pt 8 30 1920 21.9 2.60 5.2
CoCr19Pt8 27 2010 23. 1 3. 40 4CoCr 19 Pt 8 27 2010 23.1 3.40 4
CoCr19Pt8 27 1860 24 3. 12 3. 9CoCr 19 Pt 8 27 1860 24 3.12 3.9
CoCr19Pt8 27 2011 22. 8 2. 98 3. 7CoCr 19 Pt 8 27 2011 22.8 2.98 3.7
CoCr19Pt8 27 2306 21. 5 2. 90 4. 1CoCr 19 Pt 8 27 2306 21.5 2.90 4.1
CoCr19Pt8 27 2215 18. 2 2. 09 5. 7CoCr 19 Pt 8 27 2215 18.2 2.09 5.7
CoCr19Pt8 25 2526 25. 8 3. 32 3. 8CoCr 19 Pt 8 25 2526 25. 8 3.32 3.8
CoCr19Pt8 25 2756 20. 7 2. 69 4. 5CoCr 19 Pt 8 25 2756 20.7 2.69 4.5
CoCr19Pt8 25 2654 18. 6 2. 49 4. 9CoCr 19 Pt 8 25 2654 18.6 2.49 4.9
CoCr19Pta 22 2345 18. 8 1. 81 5. 8CoCr 19 Pt a 22 2345 18.8 1.81 5.8
CoCr19Pt8 22 2645 16. 7 1. 24 7. 1CoCr 19 Pt 8 22 2645 16.7 1.24 7.1
CoCr19Pt8 20 2689 19. 2 1. 74 5. 8CoCr 19 Pt 8 20 2689 19.2 1.74 5.8
CoCr19Pt8 20 2608 18 3 1. 60 6. 3 CoCr 19 Pt 8 20 2608 18 3 1.60 6.3
1  1
CoCr19Pt8 15 7^0 17. 8 1. 56 7. 5CoCr 19 Pt 8 15 7 ^ 0 17.8 1.56 7.5
CoCr19rt8 15 2800 17. 6 1. 40 8. ICoCr 19 rt 8 15 2800 17.6 1.40 8.I
CoCr19Pt8 1b /oU 1 lb. D 1 Ub 9CoCr 19 Pt 8 1b / oU 1 lb.D 1 Ub 9
Loし Γ19 1:8 O Lo then Γ 19 1: 8 O
丄 1. y 1 に y し oし r19rt8 丄 U 1 丄 1. y to y 1 to o r 19 rt 8丄 U 1
丄 4. 0 上 0 し oし r19rt8 11U 上 丄 0 し o 19 t8 7QQ 9 丄 4.0 above 0 and o r 19 rt 8 11U on 丄 0 and o 19 t 8 7QQ 9
し r I U 丄 4. Δ 上 4. L し 0し r19rt8 1 R IU 丄 4. Δ above 4. L then 0 r 19 rt 8 1
丄 U 丄 丄丄 · 77  丄 U 丄 丄 丄 · 77
上丄， 0 し 0し 8 0 1丄 Ο OΠU 丄 0 Π U . 00Q 1丄 00 0, then 0, then 8 0 1 丄 丄 OΠU 丄 0 Π U. 00Q 1 丄 00
CoCr19Pt8 8 1400 9. 5 0. 61 14CoCr 19 Pt 8 8 1400 9.5 0.61 14
CoCr19Pt8 5 1830 8. 9 0. 67 14. 5CoCr 19 Pt 8 5 1830 8.9 0.67 14.5
CoCr19Pt8 5 1750 8. 3 0. 65 13. 2 し 0し r19Pt8 3 1540 8 0. 60 13. 6CoCr 19 Pt 8 5 1750 8.30.65 13.2 then 0 r 19 Pt 8 3 1540 8 0.60 13.6
CoCr22Pt10 20 2300 21. 6 1. 82 8. 9CoCr 22 Pt 10 20 2300 21.6 1.82 8.9
CoCr22Pt10 20 2150 18. 3 1. 50 10CoCr 22 Pt 10 20 2 150 18.3 1.50 10
CoCr22Pt10 20 2090 19. 6 1. 41 8. 3CoCr 22 Pt 10 20 2090 19.6 1.41 8.3
CoCr22Pt10 20 2065 17. 2 1. 23 10. 7CoCr 22 Pt 10 20 2065 17.2 1.23 10.7
CoCr22Pt10 20 2080 15. 9 1. 00 10CoCr 22 Pt 10 20 2080 15.9 1.00 10
CoCr22Pt6 23 2060 16. 5 1. 11 9CoCr 22 Pt 6 23 2060 16.5 1.11 9
CoCr20Pt6 19 2440 16. 2 1. 13 9 los/ 6A:dfcL> sexs/一. CoCr 20 Pt 6 19 2440 16.2 1.13 9 los / 6A: dfcL> sexs / one.
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ま た 、 図 2 に v ' Isbと 保磁力 の温度係数、 図 3 に V • I s bと ノ イ ズの相 関 を示 し た。 図 3 力、 ら 明 ら 力、な よ う に 、 V · Isbが小 さ く な る に し た が い、 保磁力 の温 度係数が大き く な る 傾 向 が あ る 。 本実施例 におい て 、 保磁力 の温度係数は レマネ ンス 保磁力 の磁場印加時間 依存性のデー タ を式 （ 6 ) に フ ィ ッ テ ィ ン グ し て 求 め た熱揺 ら ぎ の影響が な い場合の レマネ ン ス 保磁力 H 0か ら 磁場印加時間 が 8 秒の と き の レマネ ン ス 保磁力 を差 し 引 い た値 を絶対温度で除 し た値 （ Hc-Hr) /Tを下 ま わ る こ と は な力、つ た。 Also, to show the correlation of V • I sb and Roh size b in temperature coefficient, as shown in FIG. 3 of the v 'I sb and the coercive force in Figure 2. As shown in Fig. 3, as V · Isb decreases, the temperature coefficient of the coercive force tends to increase as the force decreases. In this embodiment, the temperature coefficient of the coercive force is affected by the thermal fluctuation obtained by fitting the data of the dependency of the remanence coercive force on the magnetic field application time using equation (6). The value obtained by subtracting the remanence coercivity when the magnetic field is applied for 8 seconds from the remanence coercivity H 0 when no magnetic field is applied is divided by the absolute temperature (Hc-H r ) / The power to fall below T was achieved.
ま た 、 図 3 力、 ら 明 ら 力 な よ う に 、 V · I s bが小 さ く な る に し たが い、 ノ イ ズが低 く な る 。 V · I s bが約 1.5 X 10"15 emu以下の媒体で は ノ イ ズが低 く 、 高い S Z N が 得 ら れた。 In addition, as shown in FIG. 3, as the power becomes clearer, the noise becomes lower as V · Isb becomes smaller. A medium with V · I sb of about 1.5 X 10 " 15 emu or less showed low noise and high SZN.
こ れ ら の媒体 と 図 4 に示 した磁気ヘ ッ ド を用 い 、 図 Using these media and the magnetic head shown in Fig. 4,
5 に示 した磁気デ ィ ス ク 装置 を作製 した。 図 4 に於い て 、 201は記録磁極、 202は磁極兼磁気シール ド層 、 20 3は コ イ ル、 204は飽和磁束密度の大 き な磁性材料、 20 5は磁気抵抗効果素子、 206は導電体、 207は磁気シー ル ド層 、 208はス ラ イ ダ基体を示す。 The magnetic disk device shown in Fig. 5 was fabricated. In FIG. 4, 201 is a recording magnetic pole, 202 is a magnetic pole and magnetic shield layer, 203 is a coil, 204 is a magnetic material having a high saturation magnetic flux density, 205 is a magnetoresistive element, and 206 is a magnetic resistance effect element. A conductor, 207 is a magnetic shield layer, and 208 is a slider base.
ま た、 図 5 に於いて 、 211は磁気記録媒体、 212は磁 気記録媒体駆動部、 213は磁気へ ッ ド、 214… 記録再生 信号処理系 、 215は磁気へ ッ ド駆動部 を示す。  In FIG. 5, reference numeral 211 denotes a magnetic recording medium, 212 denotes a magnetic recording medium driving unit, 213 denotes a magnetic head, 214 denotes a recording / reproducing signal processing system, and 215 denotes a magnetic head driving unit.
図 2 に は、 上記磁気記録再生装置を用 いて 、 2 ギガ ビ ッ ト /平方イ ンチの記録密度で、 室温お ょ ぴ 60 °C で 測定 した場合の読み と り エ ラ ー の測定結果 を 〇 、 △お よ び - 印で示 して あ る 。 O 印 は、 エ ラ ー レー ト が 室温 お よ び 60 °C と も に実用 化可能 と 考 え ら れ る 10 11以 下 で あ っ た こ と を示 し 、 △ は、 エ ラ ー レー ト が室温で は 10 — 11以下で あ つ た が 、 60 °C で は 10 11以上で あ っ た こ と を示す。 ま た 、 - 印 は室温お よ び 60 °C と も に 10 11以 上で あ っ た こ と を示す。 FIG. 2 shows a 2-gigabyte data using the above magnetic recording / reproducing apparatus. The measurement results of the reading error when measured at a recording density of bit / square inch at room temperature and at 60 ° C are indicated by 〇, △ and-marks. O mark, the e la over rate shows and this was Tsu Oh in practical use possible and thinking we are Ru 10 11 hereinafter also the room temperature you good beauty 60 ° C, △ is, e la over rate DOO 10 at room temperature - was one Ah at 11 below, showing the this was Tsu Oh 10 11 more than 60 ° C. Also, - mark indicates a call was Tsu Oh 10 11 or more on the also the room temperature you good beauty 60 ° C.
図 2 力ゝ ら 、 2 ギガ ビ ッ ト /平方イ ンチ以上の記録密 度 を も つ磁気デ ィ ス ク 装置で、 エ ラ ー レー ト を 室温お よ び 60°C と も に実用化可能 と 考 え ら れ る 10 11以下 と す る に は、 レマネ ンス 保磁力 の温度係数が 7 0e/deg力、 ら 12 0e/deg、 かつ 1. 7 Χ (Η。- ΗΓ) /Τ以下 の媒体 を用 い る 必要が あ る こ と が ゎカゝ る 。 ま た 、 こ の条件 を満たす媒 体は、 表 1 か ら ほ と ん ど の場合、 保磁力 が 2000 0e以 上で あ り 、 磁性膜の膜厚が 10nm以上で あ り 25nm以下の も の に 限定 さ れ る こ と が分力ゝ る 。 Fig. 2 A magnetic disk device with a recording density of 2 gigabits / square inch or more, which enables practical use of error rates at room temperature and 60 ° C. and the shall be the thinking et been Ru 10 11 or less, the temperature coefficient of Remane Nsu coercivity 7 0e / deg force, et 12 0e / deg, and 1. 7 Χ (Η.- Η Γ) / Τ less In some cases, you need to use the same medium. In most cases from Table 1, media satisfying this condition have a coercive force of 20000 e or more and a magnetic film thickness of 10 nm or more and 25 nm or less. Is limited to
V - Isbが約 1. 5 X l(T15emu以下で あ り 、 温度係数が 12 Oe/degよ り 大 き い力、 1. 7 X (H。- Hr) /Tよ り 大 き い場合 に は、 室温では ノ イ ズが低 く 、 2 ギガ ビ ッ ト Z平方ィ ンチの記録密度 を も つ磁気デ ィ ス ク 装置 を作製す る こ と が で き た が 、 2 ギガ ビ ッ ト Z平方イ ンチの記録密度 で の 60 °C にお け る エ ラ ー レ ー ト を 10 11以下 にす る こ と は困難で あ っ た。 こ れは 、 保磁力 の温度係数が大 き く 、 60°C にお け る 記録では最適書 き 込み電流値か ら のず れが大 き く な る た め と 考 え ら れ る 。 なお、 温度係数が (H0-Hr) /T以下の媒体は作成で き な か っ た。 V - I sb is Ri Oh less than about 1. 5 X l (T 15 emu , a large can have force Ri by temperature coefficient is 12 Oe / deg, 1. 7 X (H.- H r) / T by Ri large At high temperatures, it was possible to fabricate a magnetic disk device with low noise at room temperature and a recording density of 2 gigabits Z square inch, but 2 gigabits. bit Z square stomach as a child you your only that e la Moltrasio over door to 10 11 below to 60 ° C in the recording density of the bench was Tsu Oh difficult. this is the temperature coefficient of the coercive force Is large This is considered to be because the deviation from the optimum write current value becomes large in the recording at 60 ° C. A medium with a temperature coefficient of (H 0 -H r ) / T or less could not be created.
さ ら に 、 温度係数力 7 Oeよ り 小 さ い媒体では、 V · I sbの小 さ な媒体が得 ら れず、 ノ イ ズが 高 く 、 こ の場合 に も 2 ギガ ビ ッ ト 平方イ ンチ以上の磁気デ ィ ス ク 装 置 を作製す る こ と が で き な か っ た。 Furthermore, a medium having a temperature coefficient force of less than 7 Oe cannot provide a medium having a small V · I sb , resulting in a high noise, and in this case also a 2 gigabit squared. It has not been possible to fabricate magnetic disk devices of more than one inch.
なお 、 磁性膜の膜厚が 8 nm以下で は、 保磁力 が 2000 Oe以下の媒体 し か得 ら れず、 出力 と と も に分解能が 低 く な つ た。  When the thickness of the magnetic film was 8 nm or less, the medium had a coercive force of 2000 Oe or less, and the resolution was low as well as the output.
[比較例 1 ] [Comparative Example 1]
実施例 と 同様、 無電解メ ッ キ の Ni- Pで被覆 した A1 - M g合金か ら な る 鏡面研磨 し た 円板上 に Cr合金下地層 を 形成 し 、 つい で CoCrTa磁性層 、 さ ら に カ ー ボ ン保護膜 を形成 し て磁気デ ィ ス ク を作製 し た。  As in the embodiment, a Cr alloy underlayer was formed on a mirror-polished disk made of an A1-Mg alloy coated with electroless Ni-P, followed by a CoCrTa magnetic layer, Then, a carbon protective film was formed on the magnetic disk.
Cr合金下地膜、 磁性層 、 保護膜は と も に Arガ ス を用 いた ス パ ッ タ リ ン グ で形成 し た。 こ の 際、 Ar圧力 は 2. 0ミ リ Torrと した。 Cr合金下地層 に は、 Cr- V、 Cr- W、 C r-Ti、 Cr- Si、 Cr- Moを用 い 、 下地組成の異な る 試料を 合計 22個用意 した。 Cr合金層 の厚 さ は 50nm、 CoCrTa 磁性層 は 19ない し は 25nm、 保護層 は 10 n mで あ る 。 CoCr Ta磁性層 の組成は CoCri5Ta4、 CoCr18Ta4お よ び CoCr16Ta 6と した。 The Cr alloy underlayer, magnetic layer, and protective film were all formed by sputtering using Ar gas. At this time, the Ar pressure was set to 2.0 milliTorr. For the Cr alloy underlayer, a total of 22 samples having different underlayer compositions were prepared using Cr-V, Cr-W, Cr-Ti, Cr-Si, and Cr-Mo. The thickness of the Cr alloy layer is 50 nm, the CoCrTa magnetic layer is 19 or 25 nm, and the protective layer is 10 nm. The composition of the CoCr Ta magnetic layer was CoCri 5 Ta 4 , CoCr 18 Ta 4 and CoCr 16 Ta 6 .
こ う して得 ら れた媒体の保磁力 Hcは 1500〜 2420 0e の範囲 に分布 し た。 ま た 、 活性化体積 V と 自 発磁化 Is bと の積 ν · Isbは 1.72力、 ら 3.64X 10-15 emuの範囲 に分 布 し、 レマネ ン ス保磁力 の温度係数 - dHr/dTは 4 か ら 6 .8 Oe/degの範囲 に分布 し た。 The coercive force H c of the resulting media and will this 1500 to 2420 0e Distributed in the range. Also, the product [nu · I sb 1.72 power of the activation volume V and spontaneous magnetization I s b, and the distribution in the range of al 3.64X 10- 15 emu, the temperature coefficient of Remane emission scan coercivity - dH r / dT ranged from 4 to 6.8 Oe / deg.
上記媒体に 、 ギ ャ ッ プ長 が 0.4 111、 卷 き 線数 24タ ー ン のパーマ ロ イ へ ッ ド を用 いて磁気情報 を記録 し 、 ノ、。 一マ ロ イ MRへ ッ ドで再生 し て電磁変換特性を調べた。 こ の 際、 記録お ょ ぴ再生時の浮上高 さ は 80nmと し た。 測定 した結果、 線記録密度 150 k F C Iで の ノ ィ ズは 15.5 〜 25 Vrnsで あ っ た。 ま た 、 再生出力 は 1. 1か ら 1.4 mV Piで あ っ た。 磁性膜組成、 磁性膜膜厚、 保磁力 、 ノ ィ ズ の測定結果、 磁気粘性の測定か ら 求 め た V · I s bの値 、 お よ び 20か ら 60 °C の範囲 で の レマネ ンス 保磁力 の温 度係数を表 2 に ま と め て示す。 Magnetic information was recorded on the above medium using a permalloy head having a gap length of 0.4111 and a winding number of 24 turns. Reproduced on a Maloy MR head, the electromagnetic conversion characteristics were examined. At this time, the flying height during recording and playback was 80 nm. As a result of the measurement, the noise at a linear recording density of 150 kFCI was 15.5 to 25 V rns . In addition, the reproduction output is 1. Tsu Oh 1 or et al. 1.4 mV P i. Magnetic film composition, magnetic MakumakuAtsu, coercive force, Roh I's of the measurement result, measurement or Luo value of the required order was V · I sb of the magnetic viscosity, Remane Nsu in the range of your good beauty 20 or et al 60 ° C Table 2 shows the temperature coefficient of coercive force.
表 2 Table 2
磁性膜組成 磁性膜膜 保磁力 Hc ノイズ ν - Isb ( X -dHr/dT 厚 、 Magnetic film composition Magnetic film film Coercive force H c noise ν-I sb (X -dH r / dT thickness,
(nm) (Oe) /ハ ノ  (nm) (Oe) / Hano
( β vrms) 10 lserau) (Oe/deg)(β v rms ) 10 ls erau) (Oe / deg)
CoCr15ra4 25 1500 25 3. 64 5. 1CoCr 15 ra 4 25 1500 25 3.64 5.1
CoCr15Ta 25 1601 24. 6 3. 58 5. 3CoCr 15 Ta 25 1601 24.6 3.58 5.3
CoCr15ra4 25 1685 24. 3 3. 49 4. 8CoCr 15 ra 4 25 1685 24.3 3.49 4.8
CoCr15Ta4 25 1723 24. 5 3. 40 4. 4CoCr 15 Ta 4 25 1723 24.5 3.40 4.4
CoCr15Ta4 25 1756 23. 6 3. 35 4. 3CoCr 15 Ta 4 25 1756 23.6 3.35 4.3
CoCr15Ta 25 1882 23. 2 3. 27 4. 6CoCr 15 Ta 25 1882 23.2 3.27 4.6
CoCr15Ta4 25 1889 22. 6 3. 19 4. 7CoCr 15 Ta 4 25 1889 22.6 3.19 4.7
CoCr15Ta4 25 1890 22. 5 3. 17 4. 2CoCr 15 Ta 4 25 1890 22.5 3.17 4.2
CoCr15Ta4 25 1926 22 3. 14 4CoCr 15 Ta 4 25 1926 22 3.14 4
CoCr15ra4 25 1956 22. 1 3. 12 4. 1CoCr 15 ra 4 25 1956 22.1 3.12 4.1
CoCr15Ta4 25 1985 21. 8 3. 07 4. 6CoCr 15 Ta 4 25 1985 21.8 3.07 4.6
CoCr15Ta 25 1989 21. 5 3. 03 4. 4CoCr 15 Ta 25 1989 21.5 3.03 4.4
CoCr15Ta4 25 2023 21. 3 2. 96 5. 1CoCr 15 Ta 4 25 2023 21.3 2.96 5.1
CoCr15Ta4 25 2056 21. 4 2. 92 5. 6CoCr 15 Ta 4 25 2056 21. 4 2.92 5.6
CoCr15Ta4 25 2122 20. 7 2. 88 4. 9CoCr 15 Ta 4 25 2 122 20.7 2.88 4.9
CoCr15Ta4 25 2146 20. 2 2. 82 5. 3CoCr 15 Ta 4 25 2 146 20.2 2.82 5.3
CoCr15Ta4 25 2250 20. 5 2. 80 5. 1CoCr 15 Ta 4 25 2 250 20.5 2.80 5.1
CoCr15Ta4 25 2280 19. 5 2. 74 4. 9CoCr 15 Ta 4 25 2 280 19.5 2.74 4.9
CoCr15Ta4 25 2420 19 2. 66 5. 4CoCr 15 Ta 4 25 2420 19 2.66 5.4
CoCr15Ta4 25 2400 18 2. 49 5. 1CoCr 15 Ta 4 25 2400 18 2.49 5.1
CoCr18Ta4 19 1850 15. 5 1. 72 6. 8CoCr 18 Ta 4 19 1850 15.5 1.72 6.8
CoCr16Ta6 25 1953 16. 5 1. 77 6. 5 CoCr 16 Ta 6 25 1953 16.5 1.77 6.5
ま た 、 図 6 に ν · Isbと レ マ ネ ン ス 保磁力 の 温度係数 、 図 7 に v ' Isbと ノ イ ズ の 相 関 を 示 し た 。 図 6 力ゝ ら 明 ら カ な よ う に 、 V · Isbが 小 さ く な る に し た カ い 、 レ マ ネ ン ス 保磁力 の 温度係数 が 大 き く な る 傾 向 が あ る 。 実 施例 と 同 様 、 レ マ ネ ン ス 保磁力 の 温度係数 は レ マ ネ ン ス 保磁力 の 磁場 印加 時 間 依 存性 の デ ー タ を 式 （ 6 ) に フ ィ ッ テ ィ ン グ し て 求 め た 熱揺 ら ぎ の 影響 が な い 場合 の レ マ ネ ン ス 保磁力 H 0か ら 磁場 印 加 時 間 が 8 秒 の と き の レ マ ネ ン ス 保磁力 を 差 し 引 い た 値 を 絶対 温度 で 除 し た値 （ Η0- ΗΓ) /Τ ( 但 し 、 Τ ： 298Κ) を 下 ま わ る こ と は な カゝ つ た 。 Fig. 6 shows the relationship between ν · Isb and the temperature coefficient of the remanence coercive force, and Fig. 7 shows the correlation between v'Isb and noise . Fig. 6 As is clear from the figure, the temperature coefficient of the remanence coercive force tends to increase as V · Isb decreases. . As in the embodiment, the temperature coefficient of the remanence coercive force is calculated by using the data of the dependency of the remanence coercivity on the time of applying a magnetic field to equation (6). The remanence coercivity when the magnetic field application time is 8 seconds is subtracted from the remanence coercivity H0 when there is no influence of the thermal fluctuations obtained by the calculation. The value was divided by the absolute temperature (Η 0 -Η Γ ) / Τ (however, Κ: 298 た).
ま た 、 図 7 力 ら 明 ら 力、 な よ う に 、 V · I s bが 小 さ く な る に し た が い 、 ノ イ ズ が 低 く な る 。 V · I s bが 2.0 X 10 -15 emu以 下 の 媒体 で は ノ イ ズ が 低 く 、 高 い S ノ N が 得 ら れ た 。 し カゝ し な が ら 、 こ れ ら の 媒 体 は保磁力 が 2000 0e以 下 で あ り 、 分解能 が 低 い 。 こ の た め 、 保磁力 の 温度係数お よ び ノ イ ズ が 比較 的 低 い に も か か わ ら ず 、 実施例 と 同 様 の磁気デ ィ ス ク 装 置 で は 、 2 ギ ガ ビ ッ ト / 平方イ ン チ の 記録密 度 （ 室温） で の エ ラ レ ー ト を 10 —11以 下 に す る こ と は 困 難 で あ っ た 。 Also, as shown in FIG. 7, the noise decreases as V · I sb decreases as the force increases. The media with V · Isb of 2.0 X 10-15 emu or less showed low noise and high S / N. However, these media have a low coercive force of less than 20000e and low resolution. For this reason, despite the fact that the temperature coefficient and noise of the coercive force are relatively low, the magnetic disk device similar to the embodiment has a 2 gigabit capacity. DOO / square Lee emissions recording density of the switch (room temperature) picture of La-les-over door 10 - 11 and this you in following the Tsu Oh in difficult.
[比較例 2 ]  [Comparative Example 2]
実施例 と 同 様 、 無 電解 メ ツ キ の Ni-Pで被覆 し た A1-M g合金 か ら な る 鏡面研磨 し た 円 板 上 に Cr合金 下 地層 を 形成 し 、 つ い で CoCrPt磁性層 、 さ ら に カ ー ボ ン保護膜 を 形成 し て 磁気デ ィ ス ク を 作製 し た 。 As in the embodiment, a Cr alloy underlayer was formed on a mirror-polished disk made of an A1-Mg alloy coated with an electroless plating Ni-P, and then a CoCrPt magnetic layer was formed. And carbon protective film Was formed to produce a magnetic disk.
Cr合金 下 地膜 、 磁性層 、 保護膜 は と も に Arガ ス を 用 い た ス ノ、。 ッ タ リ ン グ で形成 し た 。 こ の 際 、 Ar圧 力 は 2 .0ミ リ Torrと し た 。 Cr合金 下 地層 に は 、 Cr- V、 Cr - W、 Cr一 Ti、 Cr一 Si、 Cr— Moを 用 ヽ 、 下 地組成 の 異 な る 試料 を 合計 20個 用 意 し た 。 Cr合金層 の 厚 さ は 50nm、 CoCrPt 磁性層 は 25nm、 保護層 は 10nmで あ る 。 CoCrPt磁性層 の Cr含 量 は 15か ら 23原 子 パ ー セ ン ト 、 Pt含 量 は 8 原 子 パ — セ ン ト と し た 。  The underlayer, magnetic layer, and protective layer of the Cr alloy are made of Ar gas. It was formed by the butterfly ring. At this time, the Ar pressure was set at 2.0 milliTorr. Cr-V, Cr-W, Cr-Ti, Cr-Si, and Cr-Mo were used for the underlayer of the Cr alloy, and a total of 20 samples with different underlayer compositions were prepared. The thickness of the Cr alloy layer is 50 nm, the CoCrPt magnetic layer is 25 nm, and the protective layer is 10 nm. The Cr content of the CoCrPt magnetic layer was 15 to 23 atomic percent, and the Pt content was 8 atomic percent.
こ う し て 得 ら れ た 媒 体 の 保磁力 Hcは 1800〜 2800 Oe の 範 囲 に 分布 し た 。 ま た 、 活性化 体積 V と 自 発磁化 Isbと の積 ν · Isbは 2.01カ、 ら 3.43 10—15 emuの 範 囲 に 分布 し 、 レ マ ネ ン ス 保磁力 の 温度係 数 - dHr/dTは 4. 1か ら 5.9 Oe/degの 範 囲 に 分布 し た 。 The coercive force H c of the medium obtained in this way was distributed in the range of 1800 to 2800 Oe. The product ν · I sb of the activation volume V and the spontaneous magnetization I sb is 2.01 and is distributed in the range of 3.43 10−15 emu, and the temperature coefficient of the remanence coercivity is −dH The r / dT ranged from 4.1 to 5.9 Oe / deg.
上記媒体 に 、 ギ ャ ッ プ長 が 0.4/ m、 卷 き 線数 24タ ー ン の パ ー マ ロ イ へ ッ ド を 用 い て 磁気 情報 を 記録 し 、 パ 一マ ロ イ MRへ ッ ド で再生 し て 電磁変 換特性 を 調べ た 。 こ の 際 、 記録お ょ ぴ再 生 時 の 浮 上 高 さ は 80nraと し た 。  The magnetic information is recorded on the above medium using a permalloy head having a gap length of 0.4 / m and a winding number of 24 turns, and the magnetic information is recorded on the permalloy MR. And the electromagnetic conversion characteristics were examined. At this time, the recording height was set at 80 nra during recording.
測 定 し た 結果 、 線記録密 度 150 kFC Iで の ノ ィ ズ は 17 .9力 ら 30.0 X Vrmsで あ っ た 。 ま た 、 再 生 出 力 は 1.2か ら 1.45 mVp-pで あ っ た 。 磁性膜組成 、 磁性膜膜厚 、 保磁 力 、 ノ イ ズ の 測 定結果 、 磁気粘性 の 測 定 か ら 求 め た V • Isbの値 、 さ ら に 20か ら 60 °C の 範 囲 で の レ マ ネ ン ス 保磁力 の 温度係数 を 表 3 に ま と め て 示 す。 表 3 As a result of the measurement, the noise at a linear recording density of 150 kFCI was 37.9 XV rms from 17.9 force. Reproduction output was 1.2 to 1.45 mV pp . V • I sb value obtained from magnetic film composition, magnetic film thickness, coercive force, noise measurement results, magnetic viscosity measurement, and in the range of 20 to 60 ° C Table 3 summarizes the temperature coefficient of the remanence coercive force at this point. Table 3
磁性膜組成 磁性膜膜厚 保磁力 Hc ノイズ ν · Isb ( X -dHr/dT 、 Magnetic film composition Magnetic film thickness Coercive force H c noise ν · I sb (X -dH r / dT,
(nra (Oe) ( vrBS) 10一15 emu) (Oe/deg)(nra (Oe) (v rBS ) 10-15 emu) (Oe / deg)
CoCr15Pt8 25 1800 30 3. 43 4. 2CoCr 15 Pt 8 25 1800 30 3.43 4.2
CoCr15Pt8 25 1890 24. 3 3. 27 4. 5CoCr 15 Pt 8 25 1890 24.3 3.27 4.5
CoCr15Pt8 25 1820 29. 8 3. 37 4. 1CoCr 15 Pt 8 25 1820 29. 8 3.37 4.1
CoCr16Pt8 25 1850 26. 3 3. 19 4. 3CoCr 16 Pt 8 25 1850 26.3 3.194.3
CoCr17Pt8 25 1920 23. 6 2. 27 4. 7CoCr 17 Pt 8 25 1920 23.6 2.27 4.7
CoCr17Pt8 25 2010 23. 2 3. 09 5. 1 し oCr17Pt8 25 1860 22. 6 3. 00 5. 5 CoCr 17 Pt 8 25 2010 23. 2 3. 09 5. 1 Mr. oCr 17 Pt 8 25 1860 22. 6 3. 00 5. 5
CoCr18Pt8 25 2011 23. 3 3. 09 5. 2CoCr 18 Pt 8 25 2011 23.3 3.09 5.2
CoCr18Pt8 25 2306 22. 1 2. 84 4. 4CoCr 18 Pt 8 25 2306 22.1 2.84 4.4
CoCr19Pt8 25 2215 22. 2 2. 92 4. 8CoCr 19 Pt 8 25 2215 22.2 2.92 4.8
CoCr19Pt8 25 2526 21. 8 2. 82 4. 9CoCr 19 Pt 8 25 2526 21.8 2.82 4.9
CoCr20Pt8 25 2756 21. 6 2. 76 5. 1CoCr 20 Pt 8 25 2756 21.6 2.76 5.1
CoCr20Pt8 25 2654 19. 5 2. 74 4. 7CoCr 20 Pt 8 25 2654 19.5 2.74 4.7
CoCr21Pt8 25 2345 18. 8 2. 73 4. 5CoCr 21 Pt 8 25 2345 18.8 2.73 4.5
CoCr21Pt8 25 2645 18. 8 2. 54 5. 1CoCr 21 Pt 8 25 2645 18.8 2.54 5.1
CoCr22Pt8 25 2689 19. 3 2. 69 4. 7CoCr 22 Pt 8 25 2689 19.3 2.69 4.7
CoCr22Pt8 25 2608 19. 2 2. 45 4. 3CoCr 22 Pt 8 25 2608 19.2 2.45 4.3
CoCr23Pt8 25 2720 18. 3 2. 35 5. 5CoCr 23 Pt 8 25 2720 18.3 2.35 5.5
CoCr23Pt8 25 2800 19. 1 2. 19 5. 2CoCr 23 Pt 8 25 2800 19.1 2.19 5.2
CoCr23Pt8 25 2750 17. 9 2. 01 5. 9 CoCr 23 Pt 8 25 2750 17.9 2.01 5.9
ま た 、 図 8 に v ' Isbと 保磁力 の 温度係 数 、 図 9 に V • I sbと ノ イ ズ の 相 関 を 示す。 図 8 力、 ら 明 ら 力、 な よ う に 、 実施例 と 同 様 、 V · Isbが 小 さ く な る に し た が い 、 保磁力 の 温度係数 が 大 き く な る 傾 向 が あ る 。 ま た 、 本 比 較例 に お い て も 保磁力 の 温度係数 は レ マ ネ ン ス 保磁 力 の 磁場 印加 時 間 依存性 の デ ー タ を 式 （ 6 ) に フ イ ツ テ ィ ン グ し て 求 め た 熱揺 ら ぎ の 影 響 が な い 場合 の レ マ ネ ン ス 保磁力 Hoか ら 磁場 印 加 時 間 が 8 秒 の と き の レ マ ネ ン ス 保磁力 を 差 し 引 い た 値 を 絶 対温度 で 除 し た 値 （ H0-Hr) /Tを 下 ま わ る こ と は な か っ た 。 Fig. 8 shows the relationship between v'Isb and the temperature coefficient of coercive force, and Fig. 9 shows the relationship between V • Isb and noise . Fig. 8 As in the case of the embodiment, as shown in Fig. 8, the temperature coefficient of the coercive force tends to increase as V · I sb decreases, as in the embodiment. is there . Also, in this comparative example, the temperature coefficient of the coercive force is calculated by using the data of the dependency of the remanence coercive force on the application time of the magnetic field in equation (6). The remanence coercivity when the magnetic field application time is 8 seconds is subtracted from the remanence coercivity Ho when there is no influence of the thermal fluctuation and the subtraction is obtained. The value obtained by dividing the value by absolute temperature (H 0 -H r ) / T was not less than the value.
ま た 、 図 9 力 ら 明 ら 力、 な よ う に 、 V · I s bが 小 さ く な る に し た が い 、 ノ イ ズ が 低 く な る 。 し 力 し な 力 S ら 、 こ れ ら の 媒体 で は v ' Isbが 2. 0 X l(T15 eniuよ り 大 で あ り 、 ノ イ ズ が 高 い。 こ の た め 、 保磁力 の 温度係数 が 比 較 的低 い に も か か わ ら ず 、 実施 例 と 同 様 の 磁気 デ ィ ス ク 装置 で は 、 2 ギ ガ ビ ッ ト 平方 イ ン チ の 記録密 度 で の エ ラ レ ー ト を 10— 11以 下 に す る こ と は 困 難 で あ っ た 。 産業 上 の利 用 可能性 In addition, as shown in FIG. 9, the noise decreases as V · Isb decreases as the force increases. In these media, v'I sb is greater than 2.0 Xl (T 15 eniu) and the noise is higher. Therefore, the coercive force is higher. Although the temperature coefficient of the magnetic disk device is relatively low, the magnetic disk device similar to the embodiment has an error at a recording density of 2 gigabit square inch. a record over door was Tsu Oh flame frame is a child you under 10 11 or less. possibility for interest on the industry
以 上 に 述べ た よ う に 、 本発 明 に よ れ ば 、 レ マ ネ ン ス 保磁力 の 温度係数 が 7 エ ー ル ス テ ッ ド （ Oe) /度 （ d eg) 以 上 、 12 Oe/deg以 下 で あ り 、 熱揺 ら ぎ の 影響 が な い場合 の レ マ ネ ン ス 保磁力 を Ηβ， レ マ ネ ン ス 保磁力 を Ηい 絶対温度 を Τ と し た と き 、 温度係 数 が 1. 7 X { ( H。一 H r ) / T } 以下で あ る 強磁性金属薄膜を用 い て 、 再生時の媒体 ノ イ ズを低減す る と と も に 、 磁性媒体 の保磁力 の温度係数を低 く 抑 え 、 強磁性薄膜 を磁極の 一部 と す る 記録へ ッ ド と 、 磁気抵抗効果素子 を 用 い た 再生ヘ ッ ド と 組み合わせ る こ と に よ り 、 0 か ら 6 0で の 使用 温度 に耐 え る 2 ギガ ビ ッ ト 平方ィ ンチ以上の高 密度記録が 可能 と な り 、 高密度磁気デ ィ ス ク 装置 の実 現手段 と し て適 し て い る 。 As mentioned above, according to the present invention, the temperature coefficient of the remanence coercive force is 7 Oe / s (deg) or more and 12 Oe / deg. / deg Ri Ah in more than under, came to have a Les Mas of when the influence of NetsuYura et al technique is not the name value down scan coercive force Η β, the Η have absolute temperature records while the value down scan the coercive force Τ, If the temperature coefficient is 1.7 X { By using a ferromagnetic metal thin film of (H.-I H r ) / T} or less, the medium noise during reproduction is reduced and the temperature coefficient of the coercive force of the magnetic medium is reduced. In addition, by combining a recording head with a ferromagnetic thin film as a part of the magnetic pole and a reproducing head using a magnetoresistive element, the operating temperature from 0 to 60 is possible. It enables high-density recording of 2 gigabits square inch or more that can withstand high speeds, and is suitable as a means for realizing high-density magnetic disk devices.

Claims

3* 求 の 範 囲 3 * Range of request
1 . 非磁性基板上に、 下地層 、 磁性層 、 保護層 を設 け た磁気記録媒体 におい て 、 磁性層 と し て レマネ ン ス 保 磁力 の温度係数が 7 エ ー ル ス テ ッ ド （ Oe) /度 （ deg) 以上、 12 0e/deg以下で あ り 、 熱揺 ら ぎの影響が な い 場合 の レ マ ネ ン ス 保磁力 を H。， レ マ ネ ン ス 保磁力 を Hr 、 絶対温度 を T と し た と き 、 レマネ ン ス 保磁力 の温度 係数が 1. 7 X { ( H0- Hr) / T } 以下 で あ る 強磁性金 属薄膜 を用 い た こ と を特徴 と す る 磁気記録媒体。 1. In a magnetic recording medium in which an underlayer, a magnetic layer, and a protective layer are provided on a nonmagnetic substrate, the temperature coefficient of the remanence coercive force of the magnetic layer is 7 e ) / Degree (deg) or more and 120 e / deg or less, and the remanence coercive force is H when there is no influence of thermal fluctuation. , Where the remanence coercivity is H r and the absolute temperature is T, the temperature coefficient of the remanence coercivity is 1.7 X {(H 0 -H r ) / T} or less. A magnetic recording medium characterized by using a ferromagnetic metal thin film.
2 . 前記強磁性金属薄膜の保磁力 が 2000 Oe以上で あ る こ と を特徴 と す る 請求項 1 記載の磁気記録媒体。 2. The magnetic recording medium according to claim 1, wherein the coercive force of the ferromagnetic metal thin film is 2000 Oe or more.
3 . 前記強磁性金属薄膜の保磁力 が 2400 Oe以上で あ る こ と を特徴 と す る 請求項 1 記載の磁気記録媒体。3. The magnetic recording medium according to claim 1, wherein the coercive force of the ferromagnetic metal thin film is 2400 Oe or more.
4 . 前記強磁性金属薄膜の厚 さ が 10 n m以上、 25 n m 以下で あ る こ と を特徴 と す る 請求項 1 〜 3 ま での いず れかに記載の磁気記録媒体。 4. The magnetic recording medium according to any one of claims 1 to 3, wherein the thickness of the ferromagnetic metal thin film is 10 nm or more and 25 nm or less.
5 . 前記強磁性金属薄膜力 S Co-Cr - Ta, Co-Cr-Ta-Ni , Co-Cr-Pt , Co-Cr-Pt-Ta, Co_0、 Co- Ni、 Co - Cr、 Co - M o、 Co— Ta、 Co— Ni—Cr、 Co_Ni_0の群カ ら 選 ばれた コ パ ル ト を 主た る 成分 と す る 薄膜で あ る こ と を 特徴 と す る 請求項 1 ~ 4 ま でのいずれかに記載の磁気記録媒体。 5. The ferromagnetic metal thin film force S Co-Cr-Ta, Co-Cr-Ta-Ni, Co-Cr-Pt, Co-Cr-Pt-Ta, Co_0, Co-Ni, Co-Cr, Co-M Claims 1 to 4 characterized in that the film is a thin film mainly composed of a cobalt selected from the group consisting of o, Co—Ta, Co—Ni—Cr, and Co_Ni_0. The magnetic recording medium according to any one of the above.
6 . 前記強磁性金属薄膜が Crを 19原子パ ー セ ン ト 以上 含有す る コ バル ト を 主た る 成分 と す る 薄膜で あ る こ と を特徴 と す る 請求項 1 〜 4 ま で のいずれかに記載 の磁 気記録媒体。 6. The ferromagnetic metal thin film is a thin film containing cobalt as a main component containing at least 19 atomic percent of Cr. The magnetic recording medium according to any one of claims 1 to 4, characterized in that:
7 . 前記下地層 ίこ Cr、 Cr一 V、 Cr_W、 Cr— Ti、 Cr一 Siな ヽ し は Cr- Mo合金を単層 ない し は異種の金属層 か ら な る 2 層 と し て用 いた こ と を特徴 と す る 請求項 1 記載 の磁 気記録媒体。  7. The underlayers Cr, Cr-V, Cr_W, Cr-Ti, Cr-Si or Cr-Mo alloy are used as a single layer or as two layers composed of different metal layers. 2. The magnetic recording medium according to claim 1, wherein the magnetic recording medium is characterized in that:
8 . 請求項 1 に記載の磁気記録媒体 を 用 い、 強磁性薄 膜 を磁極の一部 と す る 記録へ ッ ド と 、 磁気抵抗効果素 子 を用 い た再生ヘ ッ ド と を 上記媒体 と 非接触で用 いて 、 2 ギガ ビ ッ ト Z平方イ ンチ以上の記録密度で情報 を 記録、 再生す る こ と を特徴 と す る 磁気記録再生装置。  8. Using the magnetic recording medium according to claim 1, a recording head using a ferromagnetic thin film as a part of a magnetic pole, and a reproducing head using a magnetoresistive element. A magnetic recording / reproducing apparatus that records and reproduces information at a recording density of 2 gigabits Z square inches or more without contact with the magnetic recording / reproducing apparatus.
PCT/JP1997/002017 1997-06-11 1997-06-11 Magnetic recording medium and magnetic recorder/reproducer WO1998057324A1 (en)

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Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0877543A (en) * 1994-09-08 1996-03-22 Hitachi Ltd Magnetic recording medium and magnetic recording and reproducing device
JPH08249640A (en) * 1995-03-15 1996-09-27 Hitachi Ltd Magnetic recording medium and magnetic recording device

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0877543A (en) * 1994-09-08 1996-03-22 Hitachi Ltd Magnetic recording medium and magnetic recording and reproducing device
JPH08249640A (en) * 1995-03-15 1996-09-27 Hitachi Ltd Magnetic recording medium and magnetic recording device

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