CN100555421C - Magnetic recording media and magnetic recording and transcriber - Google Patents
Magnetic recording media and magnetic recording and transcriber Download PDFInfo
- Publication number
- CN100555421C CN100555421C CNB2006800206506A CN200680020650A CN100555421C CN 100555421 C CN100555421 C CN 100555421C CN B2006800206506 A CNB2006800206506 A CN B2006800206506A CN 200680020650 A CN200680020650 A CN 200680020650A CN 100555421 C CN100555421 C CN 100555421C
- Authority
- CN
- China
- Prior art keywords
- magnetic
- layer
- magnetic recording
- recording layer
- recording media
- Prior art date
- Legal status (The legal status 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 status listed.)
- Active
Links
Images
Abstract
The invention provides a kind of magnetic recording media and a kind of magnetic recording and transcriber.Described magnetic recording media comprises substrate 11, at the lining 12 that forms in the described substrate 11, at magnetic recording layer 13 that forms on the described lining 12 and the protective seam 14 that on described magnetic recording layer 13, forms, described magnetic recording layer 13 is made of the master record layer 16 and time recording layer 15 of mutual exchange coupling.The nonmagnetic substance that described master record layer 16 has magnetic-particle and surrounds described magnetic-particle, and have the vertical magnetism anisotropy.Described time recording layer 15 is made of the material with negative crystal magnetic anisotropy, and its easy magnetization face is in the plane of described medium.
Description
The cross reference of related application
Require the right of priority of the Japanese patent application No.2005-172601 of acquisition submission on June 13rd, 2005.The application is an application of carrying out under 35U.S.C. § 111 (a), and requires to obtain the rights and interests in the applying date of the provisional application 60/693,091 of submission on June 23rd, 2005 according to 35U.S.C. § 111 (b) according to 35U.S.C. § 119 (e).
Technical field
The present invention relates to a kind of magnetic recording media and a kind of magnetic recording and transcriber.
Background technology
In the past few years, along with the increase of Computer Processing speed, wish can write down such as hard disk drive (HDD) etc. with the magnetic recording of retrieve data signal and transcriber in can realize the recording density of writing speed and Geng Gao faster.Present HDDs uses the longitudinal magnetic recording method, and wherein, direction of magnetization is positioned at the magnetic recording media plane.Yet in order to obtain higher recording density in HDDs, using direction of magnetization is favourable perpendicular to the perpendicular magnetic recording method of medium, changes because can realize rapid magnetization.
In addition, in present magnetic recording media, thermal fluctuation becomes focus, and is thick because perpendicular magnetic recording technol allows that magnetic recording layer in the medium does than in the longitudinal magnetic recording technology with regard to thermal fluctuation, so the degeneration of tracer signal can be reduced to minimum.
Research to perpendicular magnetic recording layer mainly concentrates on CoCr alloy-based (for example, the CoCrPt alloy) magnetosphere, and this magnetosphere has irregular hexagonal close packing (hcp) crystal structure.In order to solve the thermal fluctuation problem, also the material with bigger magnetic anisotropy (Ku) has been done a large amount of research.
Yet, because magnetic anisotropy Ku is proportional to coercive force (Hc), so, to having this material of big magnetic anisotropy Ku, need bigger recording magnetic field.Therefore, in this perpendicular magnetic recording medium, magnetic anisotropy Ku is set to a value near the head records ability upper limit usually.
Here,, keep big magnetic anisotropy Ku simultaneously, so just can obtain to have the perpendicular magnetic recording medium of good heat resistanceheat resistant fluctuation if coercivity H can be reduced.
Proposed apsacline perpendicular magnetic recording medium (below be called " apsacline medium ") (for example, referring to patent document 1 and 2, and non-patent document 1) recently, wherein, the direction of easy magnetizing axis tilts with respect to the normal direction of medium in the magnetic recording layer.In other words, in conventional perpendicular magnetic recording medium, the high preferred orientation of magnetic crystal particle will make easy magnetizing axis point to the normal direction of medium, and described apsacline medium is characterised in that, the high preferred orientation of magnetic crystal particle will make easy magnetizing axis tilt with respect to the normal direction of medium.
Reported in the non-patent document 1 owing to causing coercivity H to descend perpendicular to the angle between the direction of the externally-applied magnetic field direction of medium and easy magnetizing axis.Have been found that in theory when the angle between the direction of the direction of externally-applied magnetic field and easy magnetizing axis is 45 ° and can obtain minimum coercivity H.Coercive force when the coercivity H that angle is obtained when being 45 ° is about angle and is 0 ° half.
For the normal direction run-off the straight of the direction that makes the easy magnetizing axis in the magnetic recording layer, wish to use lining, so that the magnetic crystal particle that can grow and have this orientation with respect to medium.Yet, this lining that is used for the used CoCrPt alloy magnetic layer of present reality is but seldom had research.
In addition, useful in practice apsacline medium requires to have " granular structure ", and wherein the magnetic crystal particle is separated by nonmagnetic substance.Yet, in above-mentioned CoCrPt alloy magnetic layer, the method that obtains granular structure seldom there is research, wherein, in this granular structure, the orientation of magnetic crystal particle will make easy magnetizing axis (C axle) tilt with respect to the normal direction of medium.
Therefore, for the formation of film, need to solve many problems, so that obtain to use the apsacline medium of present alloy-based magnetic material.In addition, in this apsacline medium, the orientation of magnetic crystal particle has an angle, can reduce output like this, and this is undesirable.If the C axle so, the problem of demagnetization field can occur with the growth of angle at random in the magnetic transformation district, its mode is identical with situation in the conventional longitudinal magnetic recording.
In the apsacline medium, because the magnetization vector of each magnetic crystal grain is in different directions, so when making patterned medium (wherein record data or recording track shape are endowed magnetic recording layer), the magnetic properties in each figure has big variation.Even now, the magnetic-particle that on lining, can grow and be orientated with an even angle ground in a circumferential direction.
The method of the another kind acquisition apsacline medium that has proposed (for example, referring to non-patent document 2) relate to a kind of complex media, this complex media is made of the hard magnetic particles of magnetic isolation in above-mentioned grain pattern, and these hard magnetic particles have exchange coupling with the soft magnetic particles of isolating similarly.When this complex media was in the state that does not have externally-applied magnetic field, the magnetization of magnetic-particle all vertically was orientated.When applying recording magnetic field, the soft ferromagnetic layer generation reversal of magnetism makes the magnetization run-off the straight of hard magnetic layer of exchange coupling finally to have produced the apsacline medium.
This complex media does not need to make the easy magnetizing axis of hard magnetic layer to tilt, thereby does not just need to control the orientation of magnetic crystal particle.Yet, all also do not set up because have the method for the formation method of soft ferromagnetic layer of granular structure or the crystal orientation that the hard magnetic particles on the soft magnetic particles obtains, so, when making this medium, also have unsolved challenge.
In addition, in complex media,, need soft ferromagnetic layer to have big thickness in order to obtain above-mentioned effect.Yet, in this case, because the magnetization that is caused by each magnetic-particle becomes bigger, so the magnetostatic coupling between the magnetic-particle can influence the recordability or the stability of recording geometry.In addition, material design leeway becomes narrower.
Patent document 1: Japanese laid-open patent is examined please disclose JP-Hei8-129736A
Patent document 2: the open JP-3235003B of Jap.P.
Non-patent document 1:IEEE Transaction on Magnetics, Vol.38, pp.3675-3683
Non-patent document 2:IEEE Transaction on Magnetics, Vol.41, pp.537.
Summary of the invention
As mentioned above, the soft magnetism district that be difficult to obtain magnetic isolation to be realizing a kind of apsacline medium, and this apsacline medium can make the coercive force of the perpendicular magnetic recording medium with high magnetic anisotropy (Ku) and high coercive force (Hc) reduce.In addition, because saturation magnetization (Ms) should be bigger, so that the medium designs allowance finally becomes is narrow.
Proposition of the present invention is exactly in order to address the above problem.So a target of the present invention is, a kind of apsacline perpendicular magnetic recording medium is provided, the design of medium is made and helped to this magnetic recording media easily.Another target of the present invention is that a kind of magnetic recording and transcriber that uses this medium is provided.
Therefore, the invention provides following content.
(1) a kind of magnetic recording media, it comprises substrate, at the lining that forms in the described substrate, at magnetic recording layer that forms on the described lining and the protective seam that forms on described magnetic recording layer.Described magnetic recording layer is made of the master record layer and time recording layer of mutual exchange coupling.The nonmagnetic substance that described master record layer has magnetic-particle and surrounds described magnetic-particle, and have the vertical magnetism anisotropy.Described time recording layer is made of the material with negative crystal magnetic anisotropy, and its easy magnetization face is in the plane of described medium.
According to the magnetic recording media of above-mentioned (1), it is characterized in that (2) described magnetic recording layer is divided into magnetic position and non-magnetic portion in the plane of described medium, these positions are along the circumferential direction regularly arranged on described medium.
According to the magnetic recording media of above-mentioned (1) or (2), it is characterized in that (3) absolute value of the crystal magnetic anisotropy of described recording layer is at least 10
5Erg/cc.
(4) according to each the described magnetic recording media in above-mentioned (1) to (3), it is characterized in that the thickness of described recording layer is at least 1nm.
According to each the described magnetic recording media in above-mentioned (1) to (4), it is characterized in that (5) thickness of described recording layer is not more than described master record layer thickness partly.
(6) according to each the described magnetic recording media in above-mentioned (1) to (5), it is characterized in that described time recording layer comprises from CoIr, CoFe, MnSb, FeC and Fe
3One or more alloys of electing among the Pt.
(7) according to each the described magnetic recording media in above-mentioned (1) to (6), it is characterized in that described recording layer is CoIr, Ir content is 5 to 40 atomic percents.
(8) according to each the described magnetic recording media in above-mentioned (1) to (7), it is characterized in that, under described recording layer the crystal lining is arranged, the hexagonal close packing lattice of this crystal lining or the crystal face of tetragonal lattice are orientated in being parallel to the plane of described substrate.
(9) a kind of magnetic recording and transcriber, it comprises according to above-mentioned (1) each described magnetic recording media in (8), and the magnetic head that is used for read signal and write signal on described magnetic recording media.
According to above-mentioned (9) described magnetic recording and transcriber, it is characterized in that (10) described magnetic head is a single pole type head.
Description of drawings
Fig. 1 is the skeleton view of magnetic recording media of the present invention;
Fig. 2 is the sectional view of layer structure that the magnetic recording media of Fig. 1 is shown;
Fig. 3 is the synoptic diagram of the grain pattern of magnetic recording media shown in Figure 1;
Fig. 4 A is a synoptic diagram of describing magnetization inversion process in the magnetic recording media shown in Figure 1;
Fig. 4 B is a synoptic diagram of describing magnetization inversion process in the magnetic recording media shown in Figure 1;
Fig. 4 C is a synoptic diagram of describing magnetization inversion process in the magnetic recording media shown in Figure 1;
Fig. 5 is the amplification of encircled A among Fig. 1, has shown the planimetric map of discrete track media;
Fig. 6 is the amplification of encircled A among Fig. 1, has shown the planimetric map of patterned medium;
Fig. 7 is the sectional view of the patterned medium of substrate etching type;
Fig. 8 is the sectional view of the patterned medium of magnetosphere etching type;
Fig. 9 is the skeleton view of magnetic recording of the present invention and transcriber;
Figure 10 has shown the lag loop that is obtained by emulation of the present invention;
Figure 11 is the thickness of the inferior recording layer among the present invention and the graph of a relation of coercive force and squareness;
Figure 12 is the angle and the coercitive graph of a relation of externally-applied magnetic field among the present invention;
Figure 13 is the Ir content of the inferior recording layer among the present invention and the graph of a relation of magnetic anisotropy Ku;
In above-mentioned figure, numeric character 1 indication disk (magnetic recording media), 11 indication substrates, 12 indication linings, 13 indication magnetic recording layers, 14 indication protective seams, 15 indication time recording layers, 16 indication master record floor, 17 indication magnetic-particles, 18 indication nonmagnetic substances, 20 indicating graphics, 21 designation data magnetic track districts, 22 indication servo signal areas, 30 indication hard disk drives (magnetic recording and transcriber), 31 indication shells, 32 indication magnetic heads, 33 indication head suspension assemblies, 34 indication actuators, 35 indicating circuit plates, 36 indication suspensions, 37 indication cantilevers.
Embodiment
Describe magnetic recording media of the present invention and magnetic recording and transcriber below with reference to the accompanying drawings in detail.In the figure that uses with following description, for convenience's sake, some distinctive feature is exaggerated demonstration, to help to understand better the present invention.Therefore, these figure have not necessarily reacted the relative size of various piece on any precision meaning.
Magnetic recording media of the present invention is at first described.
As shown in Figure 1, magnetic recording media of the present invention is normally such as the disk 1 of used type in hard disk drive magnetic recordings such as (HDD) and the transcriber.As shown in Figure 2, this disk 1 comprise at least substrate 11, formed lining 12 in the substrate 11, formed magnetic recording layer 13 on the lining 12, on magnetic recording layer 13 formed protective seam 14.
In lining 12, also can use magnetic material.Provide between substrate 11 and magnetic recording layer 13 in the situation of the soft magnetism lining (SUL) that is made of the high magnetic permeability soft magnetic material, lining 12 can be made of the medium that is known as " vertical double-layer medium " sometimes.Soft magnetism lining SUL in this vertical double-layer medium has some functions of magnetic head, is used for magnetizing perpendicular magnetic recording layer.For example, it has such function, that is, allow to pass in the horizontal direction from the recording magnetic field of single pole type head, and make it to get back to a side of magnetic head.In addition, can be strengthened for magnetic recording layer 13 provides the ability of sufficient vertical magnetic field to make record and reproduces efficient.
Soft magnetism lining SUL can or contain nickel or the iron of cobalt constitutes by iron, and the illustrative example of this material comprises FeCo alloy (as FeCo and FeCoV), FeNi alloy (as FeNi, FeNiMo and FeNiSi), FeAl alloy or FeSi alloy (as FeAl, FeAlSi, FeAlSiCr, FeAlSiTiRu and FeAlO), FeTa alloy (as FeTa, FeTaC and FeTaN) and FeZr alloy (as FeZrN).Perhaps, described soft magnetism lining SUL also can be made of the material of the Fe that contains 60at% at least with microstructure, such as FeAlO, FeMgO, FeTaN or FeZrN; Perhaps, the material that constitutes described soft magnetism lining SUL also can have by the formed grain pattern of fine grain that is dispersed in the matrix.
In addition, also can use the Co alloy that contains Co and contain at least a element among Zr, Hf, Nb, Ta, Ti and the Y among the described soft magnetism lining SUL.Cobalt content in this cobalt-base alloy preferably is at least 80at%.When this Co alloy forms film by sputtering method, be easy to form amorphous layer.When having formed this amorphous layer, it presents outstanding soft magnetism, because this amorphous soft magnetic material does not have crystal magnetic anisotropy, crystal defect and granule boundary.In addition, use this amorphous soft magnetic material can obtain low-noise media.The preferred example of amorphous soft magnetic material has, CoZr, CoZrNb and CoZrTa alloy.
Under described soft magnetism lining SUL, can provide lining, so that strengthen the crystallinity of soft magnetism lining SUL, and the adhesion of raising and substrate 11.This lining can and comprise the alloy of these elements or its oxide or nitride constitute by for example Ti, Ta, W, Cr, Pt.
A part that constitutes in a plurality of layers of lining 12 can exist with the form in the middle layer that is made of nonmagnetic substance, and this middle layer is arranged between soft magnetism lining SUL and the magnetic recording layer 13.Described middle layer is used for cutting off the exchange coupling interaction between soft magnetism lining SUL and the magnetic recording layer 13 and controls the crystallinity of magnetic recording layer 13.The material that constitutes the middle layer has Ru, Re, Pt, Pd, W, Ti, Ta, Cr, Si and alloy thereof or its oxide or nitride.
In order to prevent sharp-pointed noise, described soft magnetism lining SUL can be divided into several layers, and for example between each layer, insert and 0.5 arrive the Ru layer of 1.5nm to form the antiferromagnetic coupling structure.Perhaps, can use pinning layer, form exchange coupling with the soft magnetism lining, this pinning layer is by the hard magnetic layer with intra-face anisotropy that constitutes such as CoCrPt, SmCo or FePt or by constituting such as antiferromagnets such as IrMn or PtMn.In this case, in order to control exchange coupling force, can on the described Ru layer or under provide one deck magnetosphere (for example, Co) or nonmagnetic layer (for example, Pt).
From lag loop, can judge between inferior recording layer 15 and master record layer 16 and whether have exchange coupling.When not having exchange coupling between the described layer, the lag loop of each layer is just overlapping simply, and when between the described layer exchange coupling being arranged, their lag loop can influence each other.A distinctive feature of the present invention is, with the exchange coupling of inferior recording layer 15 can reduce master record layer 16 intrinsic coercive force (Hc).So, the existence of exchange coupling can be confirmed by lag loop, and the coercivity H that the indicated coercivity H of this lag loop is calculated and estimated less than the magnetic anisotropy Ku that utilizes master record layer 16, and the magnetic anisotropy Ku of master record layer 16 measures by for example torque measurement (torque measurement) method.From the feature of the lag loop that will describe in detail subsequently, also can make such judgement.
Master record layer 16 is made of the hard magnetic material with perpendicular magnetic anisotropic.That is, master record layer 16 is the perpendicular magnetization layers that are made of magnetic crystal grain, and the easy magnetizing axis of most described magnetic crystal grains is along the direction orientation perpendicular to medium.Constitute by cobalt-base alloy (such as the CoPt alloy) if constitute the magnetic crystal grain of described master record layer 16, so, can obtain very big anisotropy.Except cobalt and contain chromium or the cobalt-base alloy of platinum, this magnetic crystal grain can also comprise at least a element of electing from boron, tantalum, molybdenum, copper, neodymium, tungsten, niobium, samarium, terbium, ruthenium, rhenium.By comprising these elements, the crystallinity and the orientation of magnetic crystal grain can be improved, and magnetic properties can be regulated, this feasible record and reproducing characteristic and thermal fluctuation characteristic are more suitable in high density recording.Perhaps also can use so-called " the artificial lattice of magnetic ", wherein, Co and be arranged in many layers such as noble metals such as Pt and Pd.Perhaps, can use the ordered phase alloy of forming in conjunction with platinum or palladium by iron or cobalt.And master record layer 16 self also can have sandwich construction.By the different magnetosphere of stacked two or more magnetic properties, can obtain higher recording density.
The thickness of master record layer 16 is preferably 2 to 60nm, is preferably 3 to 30nm.If the thickness of master record layer 16 is less than 2nm, so, reads the too low and noise component of output meeting and can become higher.On the other hand, it is too big that thickness can cause reading output greater than the master record layer 16 of 60nm, makes waveform distortion.Be arranged in the above-mentioned scope by thickness, can obtain to be suitable for the more magnetic recording media of high record density master record layer 16.In order to prevent the degeneration of heat resistanceheat resistant fluctuation, preferably the coercive force with master record layer 16 is set at least 237 separately, 000A/m (3kOe).The magnetic anisotropy Ku of master record layer 16 preferably is at least 10
6Erg/cc.
As shown in Figure 3, master record layer 16 has grain pattern, is made of magnetic-particle 17 and nonmagnetic substance on every side 18.In this grain pattern, each magnetic-particle 17 all separates fully, although some particles 17 are not separately, supposes that this does not constitute problem to magnetic recording.In Fig. 3, inferior recording layer 15 also has grain pattern, although for the purposes of the present invention, this time recording layer 15 can be a grain pattern, can be successive layers, perhaps also can be a kind of structure (for example, the first half is a grain pattern) that comprises the two.
By making time recording layer 15 and master record layer 16 that exchange coupling take place, property magnetic recording media of the present invention becomes a kind of apsacline medium (tilted medium).In order to realize the most of performances as the described medium of apsacline medium, the absolute value of the magnetic anisotropy Ku of inferior recording layer 15 is preferably at least 10
5Erg/cc.
Specifically, the master record layer 16 of mutually exchange coupling and time recording layer 15 bear thermal fluctuation as individual unit.Therefore, if the magnetic anisotropy Ku of inferior recording layer 15 is also little, so, the heat resistanceheat resistant fluctuation of whole magnetic recording layer can descend.For example, the complex media described in the non-patent document 2 uses magnetic anisotropy can be considered to zero soft magnetic material conduct time recording layer.So the heat resistanceheat resistant fluctuation must be provided by the master record layer fully, so the gross thickness of master record layer and time recording layer becomes big inevitably.This is undesirable for perpendicular magnetic recording medium, and in perpendicular magnetic recording medium, the distance between soft magnetism lining SUL and the record-header needs very little.Here, the easy magnetizing axis in the anisotropy of inferior recording layer 15 and master record layer 16 is orthogonal, but direction and heat resistanceheat resistant fluctuation it doesn't matter.Reason is as follows: if inferior recording layer 15 has big magnetic anisotropy Ku, so, the magnetization microstructure determines that by this two-layer balancing energy resulting structure self has the heat resistanceheat resistant fluctuation, and its magnetic anisotropy is this two-layer average magnetic anisotropy Ku.Consider this point, wish that the magnetic anisotropy Ku of time recording layer 15 is at least 10
5Erg/cc preferably is at least 1Merg/cc.
The example that satisfies inferior recording layer 15 material therefors of these conditions comprises above-mentioned CoIr, CoFe, MnSb, FeC and Fe
3Pt.In these materials, the advantage of CoIr is, it with hard disk drive at present in the used CoCrPt alloy of magnetic recording media have same hexagonal closs packing (hcp) structure; It also has similar grating constant.So when the CoIr that is formed on C axle orientation as one deck CoCrPt goes up, this CoCrPt also will become C axle orientation.In this case, the easy magnetization face that constitutes the CoIr of time recording layer 15 is the plane at described layer place, and the easy magnetizing axis of the CoCrPt of formation master record layer 16 is perpendicular to the plane at described layer place.
The C axle that is formed on the CoIr on the CoCrPt also can be along the planar orientation perpendicular to described layer place.In other words, here, the easy magnetization face that constitutes the CoIr of time recording layer 15 is exactly the plane at this layer place, and the easy magnetizing axis of the CoCrPt of formation master record layer 16 is perpendicular to the plane at described layer place.
In order to obtain to constitute CoIr time recording layer 15, C axle orientation, a crystal lining (lining 12) is placed in hope under inferior recording layer 15, being oriented in the plane parallel with the crystal face of the crystal face of hexagonal closs packing lattice or tetragonal lattice of this crystal lining.In other words, be oriented in crystal lining in the plane parallel with the crystal face of the crystal face of hexagonal closs packing lattice or tetragonal lattice by use, can obtain such film, wherein the C axle of CoIr is oriented on the direction perpendicular to this media plane.
At master record layer 16 is that CoCr alloy or inferior recording layer 15 are in the situation of CoIr, for example, can use Ru, Pt, Pd, NiCr, NiFeCr or Mg shaft vertically aligned as the C that lining 12 influences in time recording layer 15 with hexagonal close packing (hcp) structure or face-centered cubic (fcc) structure.
As mentioned above, in magnetic recording media of the present invention, no matter be the CoCrPt layer be formed on the CoIr layer, or the CoIr layer is formed on the CoCrPt layer, or CoIr layer and CoCrPt layer repeatedly in formation over each other, can make thin film planar become the easy magnetization face of the CoIr of conduct time recording layer 15, and make the plane of the easy magnetizing axis of the CoCrPt that forms master record layer 16 perpendicular to this layer place.
In addition, in magnetic recording media of the present invention, can regulate the saturation magnetization (Ms) of CoIr by the content of Ir.
Specifically, when Ir content was arranged on 5 to 40at%, the magnetic anisotropy Ku that can make time recording layer 15 was for negative, and its absolute value can be 10 at least
5Erg/cc.
The thickness of inferior recording layer 15 is preferably 0.5nm at least, more preferably 1nm at least.When the thickness of inferior recording layer 15 during less than 0.5nm, can diminish as the effect of the magnetic recording media of apsacline medium (tilted medium), in addition, also be difficult to guarantee homogeneity at whole dielectric surface.
In addition, the thickness of inferior recording layer 15 does not preferably surpass half of master record layer 16 thickness.
When the thickness of inferior recording layer 15 has surpassed a half of master record layer 16 thickness, main magnetization component becomes in face, and this can reduce signal intensity.
In addition, in property magnetic recording media of the present invention, can on protective seam 14, provide one deck lubricating layer (not shown).The illustrative example that can be used for the lubricant of described lubricating layer comprises material well known in the prior art, such as, PFPE (perfluoropolyethers), ethanol fluoride (fluorinatedalcohol) and carboxylic acid fluoride (fluorinated carboxylic acid).
Magnetic recording media of the present invention with the above-mentioned type structure can become a kind of apsacline medium, and wherein, the coercivity H of high magnetic anisotropy (Ku) material in the perpendicular magnetic recording medium can be reduced.
Here, the coercive force of describing among the present invention to be obtained with reference to figure 4A-4C (Hc) reduces the principle of the behind of effect, and wherein, Fig. 4 A-4C has schematically shown the inferior recording layer 15 and the mode of magnetization of master record layer 16 on cross-wise direction.In Fig. 4 A-4C, hollow arrow is pointed out the direction of external magnetic field, and the length of hollow arrow is represented the size of external magnetic field, and filled arrows is pointed out the direction of magnetization in each layer.
At first, shown in Fig. 4 A, when not having external magnetic field, the magnetization of inferior recording layer 15 and master record layer 16 is in fact towards single direction (among Fig. 4 A upward to).In other words, when the magnetic anisotropy of master record layer 16 can greater than the magnetic anisotropy of inferior recording layer 15 can the time, the magnetization of inferior recording layer 15 also is orientated along vertical direction.Yet, in practice, such situation is arranged also, wherein, a kind of magnetization configuration of distortion appears in the inside of inferior recording layer 15.
Then, shown in Fig. 4 B, when applying a less reversed magnetic field, the direction of magnetization of inferior recording layer 15 begins towards this one deck place planar orientation.Because master record layer 16 has exchange coupling to interact with this time recording layer 15, the direction of magnetization of master record layer 16 also begins to tilt.
Then, shown in Fig. 4 C, when the reversed magnetic field was bigger, just before master record layer 16 counter-rotating, the magnetization orientation of inferior recording layer 15 was in fact in the plane of this layer, and the direction of magnetization of master record layer 16 is about 45 °.Like this, adopt 45 ° of recording techniques, compare, can make magnetization inversion with less external magnetic field with the situation of having only master record layer 16 to exist.
The feature of magnetic recording media of the present invention is that also in media plane, magnetic recording layer 13 is divided into magnetic position and non-magnetic portion, and this magnetic position and non-magnetic portion have each zone of arranging regularly by circumferencial direction on medium.
This magnetic recording media is called as patterned medium.For example, can magnetic recording layer 13 be divided into magnetic position and non-magnetic portion by the veining figure 20 shown in the encircled A in the image pattern 1.As shown in after amplifying among Fig. 5, the surface of magnetic recording media 1 has the pulse signal of being used for and is used for the address and lead code (that is) servo signal area 22, tracking and data access control, and the data track district 21 that writes data.By above-mentioned figure 20 these zones 21 and 22 magnetic position and non-magnetic portion have been divided into.By forming above-mentioned magnetic recording layer 13, making it to become desirable shape through film modified then, perhaps, can obtain such figure 20 by adopting common film formation process in the substrate 11 that has formed desirable shape, to deposit magnetic recording layer 13.Data track district 21 can be a continuous magnetic track as shown in Figure 5, also can be as being divided into of demonstration that Fig. 6 amplifies the magnetic track of single-bit unit or multiple bit unit.
Magnetic recording media shown in Figure 5 also is known as discrete track media, and magnetic recording media shown in Figure 6 is known as patterned medium sometimes on the term of narrow sense.In discrete track media, linear recording density in present reality by determining by magnetic head formed magnetic transformation width on medium.On the other hand, in patterned medium shown in Figure 6, linear recording density is determined by the shape of giving substrate.In general, in patterned medium shown in Figure 6, can realize higher recording density.
Patterned medium comprises patterned medium of substrate etching type and the patterned medium of magnetosphere etching type, the former obtains by substrate 11 being patterned into a kind of shape that is divided into servo signal area 22 and data track district 21, as shown in Figure 7, and the latter obtains by magnetic recording layer 13 being patterned into a kind of shape that is divided into servo signal area 22 and data track district 21, as shown in Figure 8.In the patterned medium of magnetosphere etching type shown in Figure 8, as long as signal obtains from magnetic recording layer 13, etching also can extend to following lining 12 or substrate 11 so.Perhaps, can leave magnetic material (for example, only master record layer 16 being carried out graphically) in the bottom of figure.
The present invention can be used for Fig. 5 to any patterned medium shown in Figure 8, can obtain coercivity H and reduce effect in patterned zone.Therefore, patterned zone may reside on the whole medium, also can only be present on some part of medium.In addition, patterned zone can be continuous in a circumferential direction, also can be intermittently in a circumferential direction.
Magnetic recording of the present invention and transcriber are described below.
Property magnetic recording of the present invention and transcriber are illustrated by hard disk drive shown in Figure 9 (HDD) 30.Described HDD 30 uses perpendicular magnetic recording technol to read and write various types of data, it by be installed on the spindle drive motor (not shown) and can be driven the above-mentioned disk 1 that rotates, can be on disk 1 read-write magnetic head 32, be equipped with magnetic head 32 head suspension assembly 33, drive the actuator 34 of head suspension assembly 33 and the circuit board 35 that each parts are controlled constituted, these parts all are contained within the shell 31.
The record surface that head suspension assembly 33 strides across disk 1 is supporting magnetic head 32, and it contains suspension 36 and cantilever 37, at the far-end of this suspension above-mentioned slide block mechanism is installed, and cantilever 37 supports the near-end of these suspensions.Actuator 34 uses voice coil motor (VCM) by head suspension assembly 33 magnetic head 32 to be positioned at given radial position place on the disk 1.Circuit board 35 has magnetic head IC chip, carries out drive controlling and reads and writes control by magnetic head 32 by 34 pairs of magnetic heads of actuator.
Example
Effect of the present invention has been described in the example below more fully.
Example 1
In example 1, at first carry out LLG emulation to judge whether the coercivity H reduction effect in the invention described above can take place in certain usage range.Simulation result is shown in Figure 10.
In this emulation, it is 6Merg/cc that the magnetic properties of master record layer is chosen as magnetic anisotropy Ku, and saturation magnetization is 500emu/cc.The characteristic of used CoCrPt in the magnetic recording layer of these values near perpendicular magnetic recording medium.The magnetic properties of inferior recording layer is chosen as magnetic anisotropy Ku 4Merg/cc, saturation magnetization Ms 1000emu/cc.These values approach the characteristic of CoIr.The magnetocrystalline intragranular and master record layer and inferior recording layer between the exchange coupling constant all be set to 0.5 μ erg/cm.Sizing grid in the emulation is set to 1 cubic nanometer, and the employing diameter is 8nm, highly calculates as model for the cylinder of 18nm.
In result shown in Figure 10, dotted line is illustrated in highly the lag loop in the situation that only is made of the master record layer for the cylinder of 18nm.Coercivity H is about 20kOe.The thickness that solid line is illustrated in the master record layer is that the thickness of 12nm, inferior recording layer is the lag loop in the situation of 6nm; Here, coercivity H (value of the external magnetic field H during M=0) is less than half size of big value.Value M during H=0 (remanent magnetization Mr) is less than saturation magnetization Ms.This is most likely because the cause of magnetized interior component because the magnetization of inferior recording layer inside not with the master record layer in the magnetization complete matching.The curved portion of magnetization flip-flop part shows near from H=0 to Hc, and when the reversed magnetic field became bigger, magnetization component rose gradually in this face.In addition, in this part of curve, but de-rotation takes place in magnetization, and the magnetization is returned the Mr value when external magnetic field returns zero.Flip-flop at the coercivity H place is irreversible; Therefore, when external magnetic field returned zero, the magnetization became-Mr.So the magnetic field that causes magnetization inversion is Hc.As long as the magnetic anisotropy Ku of time recording layer be negative value and easy magnetization face in the plane at this layer place, this effect will take place so.
Below, under these conditions, different master record layers and time recording layer thickness are carried out emulation.The results are shown among Figure 11 of these emulation.
In these emulation, keep the gross thickness stuck-at-8nm of master record layer and time recording layer to calculate.For the saturation magnetization of inferior recording layer is that the situation of 600emu/cc is also calculated.In Figure 11, horizontal ordinate is represented the thickness of time recording layer, and ordinate is represented coercivity H and squareness S (Mr/Ms).
Can be clear that from result shown in Figure 11 even thickness has only 1nm, inferior recording layer also has the effect that coercivity H is reduced by half basically.In addition, because squareness S can reduce when the thickness increase of time recording layer, so the angle from the intensity of read signal preferably adopts the less inferior recording layer of thickness.When the thickness of inferior recording layer very hour, the variation of total heat resistanceheat resistant fluctuation diminishes.In addition, the magnetic flux that passes magnetic pole head, master record layer, inferior recording layer, middle lining and soft magnetism lining in order can run into less interference.
No matter be that the master record layer is formed on time recording layer or time recording layer is formed on the master record layer, the result is identical.Also can between the master record layer, insert time recording layer.In such circumstances, the interactional size of exchange coupling that acts on time recording layer will double, and makes squareness S near 1.
The emulation of carrying out is used for studying the angle dependence relation of property magnetic recording media of the present invention below.The results are shown among Figure 12 of these emulation.
In these emulation, the situation that the master record layer is had following value is calculated: magnetic anisotropy Ku 6Merg/cc; Saturation magnetization Ms 500emu/cc; Thickness 12nm.The value of inferior recording layer is set to: magnetic anisotropy Ku-4Merg/cc; Saturation magnetization Ms 1000emu/cc; Thickness 6nm.
When the master record layer is individual layer and magnetization inversion when deferring to so-called S-W model, coercivity H is a curve that protrudes downwards to the dependence of angle, has located minimum value at 45 °.Yet in magnetic recording media of the present invention, coercivity H presents different angle dependence relations.In other words, based on result shown in Figure 12, the value of Hc is identical near from 0 ° to 45 ° basically.Reason seemingly, it is total in the magnetization configuration that some is non-vanishing with respect to the angle in magnetic field.
Also can adopt patterned medium to realize effect of the present invention, in patterned medium, magnetic recording layer is divided into magnetic position and non-magnetic portion in media plane, this magnetic position and non-magnetic portion have the zone of arranging regularly by circumferencial direction on medium.Can be based on these consider to select suitably described medium such as the type of the HDD system that will make and production cost.
Example 2
In example 2, make 2.5 inches following disks that hard disk drive is used based on the result in the example 1.At first, non magnetic substrate of glass (TS-10SX, Ohara Inc. makes) is inserted in the vacuum chamber of sputtering system (C-3010 type, Canon ANELVA company makes), subsequently, 1 * 10
-6Form following each layer in the vacuum of Pa in substrate in succession: the thickness of being made up of CoZrNb is the soft magnetism lining of 100nm, the Ta seed layer that thickness is 5nm, the Pt lining that thickness is 10nm, the Ru lining that thickness is 10nm, CoCrPt and the SiO that thickness is t1=18nm, 17nm, 15nm, 9nm or 3nm
2Master record layer, thickness are the Co of (18-t1)=0nm, 1nm, 3nm, 9nm or 15nm
80Ir
20Inferior recording layer, thickness are the carbon protective layer of 4nm.Then, the top substrate that is formed with this rete sequence being shifted out from vacuum chamber, is that the PFPE (PFPE) of 1.3nm is as lubricant on the surface of protective seam by the method cladding thickness of dipping subsequently.Because the formation of film is carried out under vacuum state continuously, thus between master record layer and inferior recording layer, can not form such as the such contact bed of surface oxide layer, consequently, the exchange coupling attitude that can form at the interface between this is two-layer.The composition of used target is ((Co when forming the master record layer
90Cr
10)
80Pt
20)
90-(SiO
2)
10Here, the atomic percent of the numeral component in the bracket.
Then, prepared magnetic recording media is cut, cutting mode will make it possible to check time recording layer and master record layer segment by transmission electron microscope (TEM).Find that in this way described medium has grain pattern, this structure is made of the nonmagnetic substance of magnetic-particle and these particles of encirclement as shown in Figure 3.This sample thickness is about 10nm.Carry out order EDX and measure, confirm thus, very low from the signal of Ru lining.
The nonmagnetic substance part of described medium is mainly by SiO
2Constitute.EDX to this part analyzes confirmation, has Co and Cr peak.As if in view of the component of master record layer of being surveyed in EDX analyzes and time recording layer, inferior recording layer and master record layer are partly located to have overlapping at magnetic-particle.So, find that therefrom the cross-sectional structure of this sample is similar shown in Figure 2 with the xsect of transmission electron microscope (TEM) sample for reference.As if in addition, in inferior recording layer, do not isolate each particle, really owing to having formed granular structure from the diffusion of master record layer such as elements such as silicon although add special element week.During as if such granular structure partly formed by inferior recording layer CoIr on relevant CoCrPt alloy selective deposition and during this film forms, form inevitably such as the oxide of Co-O mainly by SiO
2Selective deposition on the matrix material that constitutes causes.
When the thickness t 1 of master record layer is 18nm, that is, when not having inferior recording layer, coercivity H is 5.4kOe.When thickness t 1=17nm, the 15nm of master record layer, 9nm or 3nm, the lag loop of each sample in these samples is all with shown in Figure 10 similar.In addition, when the place of magnetization flip-flop estimation coercivity H, resulting result is respectively 3.9kOe, 3.5kOe, 2.8kOe and 2.5kOe in each sample.In each situation, confirm to have coercivity H to reduce effect, but reducing of Hc is different with above-mentioned simulation result.Possible reason is, the vertical magnetism anisotropy of master record layer is not fully perpendicular to the planar orientation of this layer; Generation be its angle have an appointment 5 ° the variation and/or the variation of strength under restriction 10%.
Based on the estimation that is obtained by torque measurement (torque measurement), find that the magnetic anisotropy Ku of CoIr is about-4Merg/cc.Master record layer thickness t1 is that the sample of 3nm has little residual magnetization Mr.This medium can not be used for magnetic recording media.
Then, use the magnetic recording media as time recording layer, build as shown in Figure 9 magnetic recording and transcriber by CoIr.In this magnetic recording and transcriber, adopt ring-like magnetic head commonly used in vertical medium as write head, the disk velocity of rotation is set at 4500rpm, the signal of record 50MHz.The result is to write the sample of coercivity H less than 3kOe.Because in other sample, can not intactly write, so, on oscillograph, can clearly observe the distortion of waveform.
Then, with above-mentioned same condition under, use to have single pole type head and carry out write operation as the magnetic recording and the transcriber of write head.Observe for containing the sample of thickness t 1 and can carry out complete writing for the master record layer of 17nm, 15nm or 9nm.For containing the sample of thickness t 1 for the master record layer of 18nm, can not write well, on oscillograph, observed the distortion of waveform.
Example 3
Make a kind of magnetic recording media, except the thickness t 1 of the master record layer of prepared sample is set to 9nm, the material that constitutes time recording layer is CoFe, MnSb, FeC or Fe
3Outside the Pt, this medium is identical with magnetic recording media in the example 2.The coercivity H of all these samples is 3 to 4kOe, and this shows, has obtained coercivity H and has reduced effect.
Example 4
Prepare a kind of magnetic recording media, except in substrate, forming following layer in succession: CoIr and SiO that Ru lining, the 5nm that Ti lining, the 3nm that 7nm is thick is thick is thick
2Outside the thick carbon protective layer of inferior recording layer, 4nm, this medium is identical with magnetic recording media in the example 2.Described CoIr-SiO
2Layer passes through Co-SiO
2The sputter simultaneously of target, Co target and Ir target three sources forms.
In example 4, at first, SiO
2Volume ratio be made as 10%, measure different I r atomic composition than under magnetic anisotropy Ku.These the results are shown among Figure 13.Clearly from Figure 13 seeing, although pressure (using argon gas as the sputter gas) difference when forming owing to film has produced different results, is 5 to arrive in the scope of 40at% at Ir content, and magnetic anisotropy Ku is negative value.
Then, use by CoIr-SiO
2As the magnetic recording media of inferior recording layer, build as shown in Figure 9 magnetic recording and transcriber.Obtain magnetic recording media by on substrate of glass, forming following each layer in succession: CoIr and SiO that Ru lining, the 5nm that Ti lining, the 3nm that 7nm is thick is thick is thick
2Inferior recording layer, CoCrPt and SiO that 13nm is thick
2Master record layer, the carbon protective layer that 4nm is thick.Because this magnetic recording media does not use soft magnetism lining (SUL), so can use ring-like magnetic head to carry out record.
Preparation Ir atomic composition is carried out write operation than being respectively 0,5,10,20,30,40 and the magnetic recording media of 50at% under the condition identical with above-mentioned condition.At Ir content is on the magnetic recording media of 0at% and 50at%, owing to can not intactly write, so on oscillograph, can observe the distortion of waveform.At Ir content is in the magnetic recording media of 0at%, and the cause that this most likely increases owing to average saturation magnetization because inferior recording layer is made of Co fully, causes owing to magnetostatic interaction has formed magnetic domain arbitrarily.At Ir content is in the magnetic recording media of 50at%, and the saturation magnetization Ms of inferior recording layer is little, magnetic anisotropy Ku be on the occasion of.This causes the coercivity value of coercive force near the master record layer, thereby cannot use ring-like magnetic head to carry out record.In all other magnetic recording medias, can obtain coercivity H and reduce effect, thereby even use ring-like magnetic head also can carry out common write operation.
Example 5
Prepare a kind of magnetic recording media, except in substrate, forming thick CoCrPt and the SiO of 7nm thick Ti lining, 10nm in succession
2Master record layer, CoCrPt and SiO that inferior recording layer, 5nm that 3nm is thick are thick
2Outside the thick carbon protective layer of master record layer and 4nm, this magnetic recording media is identical with magnetic recording media in the example 2.The coercivity H of this magnetic recording media is estimated as 3.0kOe, and this shows even can obtain ratio 2 better coercivity H reduction effects.Find also that in addition squareness has improved.
Then, use this magnetic recording media to build as shown in Figure 9 magnetic recording and transcriber, under the condition identical, carry out write operation with example 2.Use single pole type head as write head.So, be that situation in the example 2 of 15nm is compared with master record layer thickness t1, signal intensity has increased by 10%, and signal to noise ratio (snr) has increased about 2dB.This is most likely because coercivity H reduces the cause that effect is bigger and squareness increases.
Industrial applicibility
As mentioned above, the invention provides a kind of apsacline perpendicular magnetic recording medium, by having The master record layer of kernel structure exchanges coupling with the inferior recording layer with negative crystal magnetic anisotropy Close, can easily produce this magnetic recording media, and make it carry out easily medium designs. The present invention Magnetic recording and the transcriber of so a kind of magnetic recording media of use also are provided.
Claims (10)
1. magnetic recording media comprises:
Substrate;
The lining that in described substrate, forms;
The magnetic recording layer that on described lining, forms; And
The protective seam that on described magnetic recording layer, forms,
Wherein, described magnetic recording layer comprises
The nonmagnetic substance that master record layer, this layer have magnetic-particle and surround described magnetic-particle, and have the vertical magnetism anisotropy; And
Inferior recording layer, this layer is made of the material with negative crystal magnetic anisotropy, and its easy magnetization face is orientated the plane that is parallel to described medium, and
Between described master record layer and described recording layer exchange coupling is arranged.
2. magnetic recording media according to claim 1, wherein, described magnetic recording layer is divided into magnetic position and non-magnetic portion in the plane of described medium, described magnetic position and non-magnetic portion have each along the circumferential direction regularly arranged on described medium zone.
3. magnetic recording media according to claim 1, wherein, the absolute value of the crystal magnetic anisotropy of described recording layer is at least 10
5Erg/cc.
4. magnetic recording media according to claim 1, wherein, the thickness of described recording layer is at least 1nm.
5. magnetic recording media according to claim 1, wherein, the thickness of described recording layer is not more than half of described master record layer thickness.
6. magnetic recording media according to claim 1, wherein, described time recording layer comprises one or more from CoIr, CoFe, MnSb, FeC and Fe
3The alloy of electing among the Pt.
7. magnetic recording media according to claim 1, wherein, described recording layer is CoIr, and Ir content is 5 to 40 atomic percents.
8. magnetic recording media according to claim 1, this medium has the crystal lining under described recording layer, and the crystal face of the hexagonal close packing lattice of this crystal lining or the crystal face of tetragonal lattice are orientated in being parallel to the plane of described substrate.
9. magnetic recording and transcriber comprise:
Magnetic recording media according to claim 1, and
The magnetic head that is used for read signal and write signal on described magnetic recording media.
10. magnetic recording according to claim 9 and transcriber, wherein, described magnetic head is a single pole type head.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP172601/2005 | 2005-06-13 | ||
| JP2005172601A JP4405436B2 (en) | 2005-06-13 | 2005-06-13 | Negative anisotropic exchange coupled magnetic recording medium and magnetic recording / reproducing apparatus |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101203908A CN101203908A (en) | 2008-06-18 |
| CN100555421C true CN100555421C (en) | 2009-10-28 |
Family
ID=37646749
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB2006800206506A Active CN100555421C (en) | 2005-06-13 | 2006-06-09 | Magnetic recording media and magnetic recording and transcriber |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JP4405436B2 (en) |
| CN (1) | CN100555421C (en) |
Families Citing this family (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007081246A (en) * | 2005-09-15 | 2007-03-29 | Mitsumi Electric Co Ltd | Magnetic film and magnetic device |
| JP2007250150A (en) * | 2006-03-20 | 2007-09-27 | Fujitsu Ltd | Perpendicular magnetic recording medium |
| JP2008084432A (en) * | 2006-09-27 | 2008-04-10 | Hoya Corp | Magnetic recording medium and manufacturing method of magnetic recording medium |
| JP4687645B2 (en) * | 2006-12-25 | 2011-05-25 | Ｔｄｋ株式会社 | Magnetic recording medium, magnetic recording / reproducing apparatus, and concave / convex depth inspection method for concave / convex pattern |
| JP2008204493A (en) * | 2007-02-16 | 2008-09-04 | Fujitsu Ltd | Discrete type magnetic recording medium |
| JP2008287829A (en) * | 2007-05-21 | 2008-11-27 | Toshiba Corp | Vertical magnetic recording medium |
| JP2009087501A (en) | 2007-10-03 | 2009-04-23 | Showa Denko Kk | Perpendicular magnetic recording medium and magnetic recording and reproducing device |
| JP2009087500A (en) | 2007-10-03 | 2009-04-23 | Showa Denko Kk | Perpendicular magnetic recording medium and magnetic recording and reproducing device |
| KR101390950B1 (en) * | 2007-11-23 | 2014-05-02 | 시게이트 테크놀로지 엘엘씨 | Magnetic recording media and method of fabricating the same |
| FR2924261A1 (en) * | 2007-11-26 | 2009-05-29 | Commissariat Energie Atomique | MAGNETIC RECORDING MEDIUM |
| JP2009199691A (en) * | 2008-02-22 | 2009-09-03 | Hitachi Global Storage Technologies Netherlands Bv | Magnetic recording medium and method for manufacturing thereof |
| JP2009205730A (en) * | 2008-02-27 | 2009-09-10 | Sony Corp | Perpendicular magnetic recording medium and magnetic recording/playback device |
| US9311948B2 (en) * | 2008-12-31 | 2016-04-12 | Seagate Technology Llc | Magnetic layering for bit-patterned stack |
| JP2010198674A (en) * | 2009-02-24 | 2010-09-09 | Hoya Corp | Magnetic recording medium and method for manufacturing magnetic recording medium |
| JP5677789B2 (en) * | 2010-09-08 | 2015-02-25 | 昭和電工株式会社 | Magnetic recording medium and magnetic recording / reproducing apparatus |
| JP2014103172A (en) | 2012-11-16 | 2014-06-05 | Toshiba Corp | Magnetic thin film, manufacturing method therefor, high frequency oscillation device using magnetic thin film, magnetic head, magnetic recording medium, and magnetic recorder/reproducer |
| JP7189520B2 (en) * | 2018-03-30 | 2022-12-14 | 田中貴金属工業株式会社 | sputtering target |
-
2005
- 2005-06-13 JP JP2005172601A patent/JP4405436B2/en active Active
-
2006
- 2006-06-09 CN CNB2006800206506A patent/CN100555421C/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN101203908A (en) | 2008-06-18 |
| JP2006351058A (en) | 2006-12-28 |
| JP4405436B2 (en) | 2010-01-27 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN100555421C (en) | Magnetic recording media and magnetic recording and transcriber | |
| US11138997B2 (en) | Multilayer exchange spring recording media | |
| CN100589187C (en) | Perpendicular magnetic recording disk and manufacturing method thereof | |
| US8116035B2 (en) | Magnetic recording medium having a secondary recording layer made of a material having a negative crystal magnetic anisotropy and magnetic recording and reproducing apparatus | |
| US7910159B2 (en) | Radial magnetic field reset system for producing single domain soft magnetic underlayer on perpendicular magnetic recording medium | |
| JP4292226B1 (en) | Perpendicular magnetic recording medium and magnetic recording / reproducing apparatus using the same | |
| US6636400B2 (en) | Magnetoresistive head having improved hard biasing characteristics through the use of a multi-layered seed layer including an oxidized tantalum layer and a chromium layer | |
| CN101809659B (en) | Vertical magnetic recording medium and magnetic recording and reproducing device | |
| JP2006190461A (en) | Perpendicular magnetic recording medium using magnetically resettable single magnetic domain soft underlayer | |
| CN101339775A (en) | Perpendicular magnetic recording medium and magnetic recording apparatus | |
| JP2008176923A (en) | Perpendicular magnetic recording medium | |
| CN101816042A (en) | Vertical magnetic recording medium and magnetic recording reproduction device | |
| CN101828222A (en) | Vertical magnetic recording medium, method for production thereof, and magnetic recording/reproduction device | |
| JP2012195027A (en) | Magnetic recording medium, method of manufacturing the same, and magnetic recording/reproducing apparatus | |
| CN102356430A (en) | Magnetic recording medium and memory device | |
| CN105321536A (en) | Magnetic recording medium and magnetic recording and reproducing apparatus | |
| EP1490867A1 (en) | Magnetic recording medium and magnetic storage apparatus | |
| CN100543843C (en) | Perpendicular magnetic recording medium and manufacture method thereof and magnetic recording and transcriber | |
| US8877360B2 (en) | Magnetic recording medium with a plurality of pinning portions in the magnetic layer | |
| US20090201607A1 (en) | Patterned perpendicular magnetic recording medium and magnetic recording and reproducing apparatus | |
| JP5444447B2 (en) | Magnetic recording medium, manufacturing method thereof, and magnetic recording / reproducing apparatus | |
| US7092209B2 (en) | Longitudinal magnetic recording using magnetic media with a soft underlayer | |
| JP2007102833A (en) | Perpendicular magnetic recording medium | |
| CN101169939B (en) | Perpendicular magnetic recording medium, method of fabricating the same, and magnetic recording system | |
| JP2006269067A (en) | Magnetic recording medium and magnetic storage apparatus |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20180329 Address after: Miyagi Prefecture in Japan Co-patentee after: SHOWA DENKO Kabushiki Kaisha Patentee after: TOHOKU University Co-patentee after: Toshiba Electronic Devices & Storage Corporation Address before: Miyagi Prefecture in Japan Co-patentee before: SHOWA DENKO Kabushiki Kaisha Patentee before: TOHOKU University Co-patentee before: Toshiba Corp. |
|
| TR01 | Transfer of patent right | ||
| CP01 | Change in the name or title of a patent holder |
Address after: Miyagi Prefecture, Japan Patentee after: TOHOKU University Patentee after: Lishennoco Co.,Ltd. Patentee after: Toshiba Electronic Devices & Storage Corporation Address before: Miyagi Prefecture, Japan Patentee before: TOHOKU University Patentee before: Showa electrical materials Co.,Ltd. Patentee before: Toshiba Electronic Devices & Storage Corporation |
|
| CP01 | Change in the name or title of a patent holder | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20230505 Address after: Miyagi Prefecture, Japan Patentee after: TOHOKU University Patentee after: Showa electrical materials Co.,Ltd. Patentee after: Toshiba Electronic Devices & Storage Corporation Address before: Miyagi Prefecture, Japan Patentee before: TOHOKU University Patentee before: SHOWA DENKO Kabushiki Kaisha Patentee before: Toshiba Electronic Devices & Storage Corporation |
|
| TR01 | Transfer of patent right |