JPS6043203A - Vertical magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To improve the recording density when the magnetic permeability of a base layer is increased, and to obtain necessary frequency characteristics by using a composite magnetic recording medium and a one-surface closed magnetic path type composite vertical magnetic head, and providing the base layer of said medium with magnetic anisotropy in the plane parallel to recording surfaces. CONSTITUTION:The composite magnetic recording medium 6 has the base layer 6b with >=2,000 specific magnetic permeability and a vertical magnetism film 6c, and the base layer 6b is provided with the magnetic anisotropy in the recording surfaces. The composite vertical magnetic head 7 has a main magnetic pole 1, magnetic material blocks 5a and 5b, and winding, and is arranged facing the film 6c. This base layer is formed on an amorphous film consisting principally of Co-Zr-Nb. In this case, magnetic flux B flows in the film 6c in the thickness direction as shown by an arrow 71, but flows in the base layer 6b in parallel to the film surface of the base layer as shown by an arrow 72. Thus, the recording efficiency is increased. Further, the base layer is provided with the magnetic anisotropy in a plane parallel to the recording surfaces of the recording medium, so excellent recording and reproduction are performed in an audio or video band.

Description

[Detailed Description of the Invention] [Technical Cup Field 1] The present invention uses a high permeability magnetic material as an underlayer.1. - Written on the composite magnetic recording medium at a vertical 141-type head "Ij1.
This invention relates to perpendicular magnetic recording for reproduction.

[Prior art tfj] The perpendicular magnetic recording method, in which a recording medium is magnetized in the thickness direction, is suitable for high-density recording because, in principle, short wavelengths reduce the amount of depletion in the recording medium. In order to perform such perpendicular magnetic recording well, the recording head that generates a strong perpendicular component (4) and a recording medium with anisotropy in the vertical direction *2, :l, Do whatever is necessary.

Conventionally, various types of perpendicular magnetization heads have been proposed. FIGS. 1, 2, and 3 show examples of this.

FIG. 1 shows a main pole-excited perpendicular magnetic head having a structure in which a magnetic head having a main pole 1 made of a high permeability magnetic thin film and a winding 2 is disposed facing one side of a recording medium 3. As shown in FIG. In FIG. 2, a magnetic head consisting of a main magnetic pole 1 made of a high permeability magnetic thin film and an auxiliary magnetic pole 4 made of a high permeability magnetic block with a winding 2 is arranged so as to face both sides of a recording medium 3. This is an auxiliary magnetic pole-excited perpendicular magnetic head with 8 components. Fig. 3 shows a main magnetic pole 1 made of a high permeability magnetic thin film, and a pair of 1]-shaped magnetic blocks sandwiching the main magnetic pole 1 from both sides. []
A composite device in which a single-shaped magnetic head consisting of blocks 5'a, 5b and a winding 2 attached to the outer periphery of the sandwiched portion of the magnetic blocks 5a, 5b is arranged so as to face one side of the recording medium 3. This is a perpendicular magnetic head. In all of these, during recording, the main magnetic pole 1 is magnetized by the current flowing through the winding 2 wound around the main magnetic pole 1 or the auxiliary magnetic pole 4, and this main magnetic pole 1
The recording medium 3 is magnetized by a perpendicular magnetic field generated by the magnetization. Further, during reproduction, 1 magnet (~1) is magnetized by [5in] generated from the magnetized portion of the recording medium 3, and a voltage induced in the J-shaped winding 2 due to this change in magnetization of the main pole 1 is extracted.

By the way, in the main magnetic pole 1 shown in FIG. It becomes saturated and it is impossible to avoid generating a sufficient lltI flux from the tip portion that contacts the recording medium 3 for recording.Therefore, as shown in FIG. A composite (magnetic recording medium 6) was proposed in which a perpendicularly magnetized film 6C lined with J was provided.If this composite magnetic recording medium 6 was used, the recording sensitivity would be improved.However, The magnetic field R of winding 2 records! 1%! The tip of winding 2 (9k) has to be moved back a little from the tip of 1 (・5i 1) to avoid directly affecting the body. 1!1 No. (As a result, 1-A strong magnetizing force acts on C in the part where winding 2 of magnetic pole 1 is wound, but at the tip part that protrudes from the winding part of main pole 1, The level drops rapidly.

In the auxiliary pole excitation type perpendicular magnetic head shown in Fig. 2, the winding 2
The auxiliary magnetic pole 4 is magnetized by the signal current flowing through the auxiliary magnetic pole 4, and the magnetic field generated from the auxiliary magnetic pole 4 is concentrated at the tip of the main magnetic pole 1. Therefore, only the portion of the magnetic recording medium 3 that comes into contact with the main pole 1 is magnetized, and excellent recording characteristics can be obtained.

However, since it is necessary to make the main magnetic pole 1 and the auxiliary magnetic pole 4 face each other and insert the magnetic recording medium 3 between the two magnetic poles to perform recording and reproduction, the device becomes larger and, when applied to a VTR, etc., it is difficult to load the head. Make it complicated.

In the composite perpendicular magnetic head shown in FIG. 3, a signal current is passed through the winding 2 (and a magnetic flux B is generated, forming a closed magnetic path shown by the arrow. As a result, the portion of the magnetic recording medium 3 facing the magnetic poles is vertically In this way, the one shown in Fig. 3 has a closed magnetic circuit configuration and is configured to perform recording and reproduction on only one side of the magnetic recording medium 3, so the structure shown in Figs. The drawbacks in the head are solved. However, if the composite magnetic recording medium 6 shown in FIG. 4 is used instead of the magnetic recording medium 3, the underlayer 6b is interposed in the closed magnetic path. The magnetic permeability μ of the magnetic layer 6b has a large effect on the recording sensitivity.In other words, in the ones shown in FIGS. 1 and 2, only the magnetic field perpendicular to the recording medium 6 is used. In other words, the magnetic permeability μ of the underlayer 6b is not so much of a problem, but in the case of FIG. 3, the underlayer 6b is interposed in a part of the closed magnetic path, so the magnetic permeability μΩ value has a large effect on recording sensitivity. On the other hand, the base layer 6
The frequency characteristics are affected by the magnetization characteristics of b.

〔the purpose〕

An object of the present invention is to improve recording sensitivity when the magnetic permeability of the underlayer is increased in a composite magnetic recording medium using a high magnetic permeability magnetic material as an underlayer for recording and reproducing with a perpendicular magnetization head. It is an object of the present invention to provide a perpendicular magnetic recording and reproducing device that can perform sufficiently good recording and reproducing in audio or video bands.

〔overview〕

In order to achieve the above object, the present invention is characterized by the following configuration. In other words, the recording medium is a composite magnetic material that has a perpendicularly magnetized film made of a magnetic material with an axis of easy magnetization perpendicular to the film surface, and an underlayer made of a high permeability magnetic material provided on the back surface of this perpendicularly magnetized film. Use a recording medium. Then, on one side of this composite magnetic recording medium, a single-sided closed magnetic circuit type composite perpendicular magnetic pole is formed by magnetically coupling a main magnetic pole made of a wound high permeability magnetic thin film and an auxiliary magnetic pole made of a magnetic block. Place the head.

Then, the underlayer made of a high permeability magnetic material provided on the back surface of the perpendicularly magnetized film is provided with magnetic anisotropy in a plane parallel to the recording surface of the recording medium. In this way, when the magnetic permeability of the underlayer is increased, the recording sensitivity can be improved and the frequency characteristics can be made as desired.

〔Example〕

FIG. 5 is a diagram showing an embodiment of the present invention, and the same parts as in FIGS. 3 and 4 are given the same reference numerals. The composite magnetic recording medium 6 has an underlayer 6b made of a high permeability magnetic material with a relative permeability of 2000 or more as an underlayer on a non-magnetic base 6a.
A perpendicular magnetization film 6C having an axis of easy magnetization in a direction perpendicular to the film surface is provided thereon. The underlayer 6b is provided with magnetic anisotropy within the recording surface of the recording medium 6. The composite perpendicular magnetic head 7 has a main magnetic pole 1 made of a high permeability magnetic thin film and a pair of U-shaped magnetic blocks 5.
a and 5b from both sides, and the winding 2 is placed between the sandwiched parts.
It has been subjected to This composite perpendicular magnetic head 74 is arranged to face one side of the composite magnetic recording medium 6, that is, the perpendicular magnetization film 6C.

FIG. 6 shows the relationship between the relative magnetic permeability and magnetic flux density of the underlayer 6b in the recording medium 6, that is, the recording sensitivity, when a single-sided closed magnetic path type composite perpendicular magnetic head 7 is used in combination with the composite magnetic recording medium 6. This is an experimental result. FIG. 6 also shows experimental results for magnetic heads of the types shown in FIGS. 1 and 2 as comparative examples.

The horizontal axis in FIG. 6 shows the relative magnetic permeability μ of the underlayer 6b made of a high magnetic permeability magnetic material, and the vertical axis shows the magnetic flux density By (relative value) in the perpendicular magnetization Ml 6 C near the tip of the main pole 1. It shows. Curve ■ is the characteristic curve when using the main pole excitation type perpendicular magnetic head shown in Figure 1, curve ■ is the characteristic curve when using the auxiliary pole excitation type perpendicular magnetic head shown in Figure 2, and curve ■ is a characteristic curve when the composite vertical magnetic head 7 of single-sided closed magnetic path type adopted in this embodiment is used. As is clear from the results shown in Fig. 6, in the main pole-excited perpendicular magnetic head, even if the relative permeability μ of the underlayer is increased as shown by curve 1, no significant effect is observed, and other It can be seen that this type is very disadvantageous compared to the two types. Now, a comparison is made between an auxiliary pole-excited perpendicular magnetic head as shown by curve ⋯ and a composite perpendicular magnetic head as shown by curve ◯. The relative magnetic permeability μ is approximately 2.
000 or less, the auxiliary pole excitation type perpendicular magnetic head has better recording efficiency. However, when the relative permeability μ is 2000 or more, as the relative permeability increases, the recording efficiency increases rapidly in the composite perpendicular magnetic head, whereas in the auxiliary pole-excited perpendicular magnetic head it decreases and the relative permeability increases to μm100.
00, there is not much difference compared to the case of the main pole excitation type vertical magnetic head. This is the base layer 6.
As the relative magnetic permeability μ of b increases, the magnetic resistance of the underlayer decreases, and as a result, in the composite perpendicular magnetic head, magnetic loss decreases and magnetic energy is used effectively, whereas auxiliary magnetic pole excitation This is thought to be because the effect of the auxiliary magnetic pole is blocked in the type perpendicular magnetic head, and the effect is similar to that of the main pole-excited perpendicular magnetic head.

This is also supported by the state of the magnetic flux flow and magnetic flux density within the recording medium 6 shown in FIG.

FIG. 7 conceptually shows the flow of magnetic flux and the magnitude of the magnetic flux density within the composite magnetic recording medium 6 when recording is performed using the composite perpendicular magnetic head 7. As is clear from this figure, the magnetic flux B flows in the thickness direction of the thin film in the perpendicularly magnetized film 6c as shown by the arrow 71, but in the underlayer 6b made of a high permeability magnetic material as shown by the arrow 72, the magnetic flux B flows in the thickness direction of the thin film as shown by the arrow 72. Flows parallel to the membrane surface.

In this way, this example has a very high relative permeability (2
Since the composite magnetic recording medium 6 having an underlayer made of a high permeability magnetic material (000 or more) is combined with a composite perpendicular magnetic head having a single-sided rJff magnetic path, perpendicular magnetic recording with extremely high recording efficiency is achieved. A recording and reproducing device can be obtained.

Next, we will discuss how to make an underlayer with high magnetic permeability. The magnetic film itself, which has an initial magnetic permeability μi of about 5000 and can be used in a frequency band of 10 MHz, can be manufactured using conventional techniques. - As an example, for the main pole film of a perpendicular magnetic recording head, a Go-Zr-Nb alloy target is sputtered onto a main pole substrate to form an amorphous magnetic film.
By annealing at a temperature of about 00°C and using the hard axis of magnetization of the magnetic film, the initial magnetic permeability μi is about 5000 and I
We have obtained something that can be used in the OMH2 frequency band. However, since the base material of a general floppy disk type recording medium is an organic material film with a thickness of approximately 30 to 75 μm, it is impossible to perform annealing at 400''C. It is necessary to use a magnetic material with a low temperature, or [2] use a material that does not require annealing, or [3] use a material that does not cause defects even when annealed. In this example, the above [2] and [An example is shown in which 3 units are used.

FIG. 8 shows an example of how to make an underlayer in a low frequency recording medium, and a part of the method is applied to a tape for a DAT (digital audio table recorder).

A base film is applied by continuous sputtering to a part of the continuously running roll tape 8 (a rough area E is provided, and an arrow
A pair of magnets 9A so that magnetic flux is generated in the direction of
9B).

The easy axis of magnetization of the sputtered underlayer is oriented in the direction of arrow Y after sputtering. Note that arrow Z indicates the tape running direction. Digital A-diotape uses a frequency band of 100Kt-1z, so as mentioned above, the frequency characteristics are not as good as LET, but the initial permeability μ
If the axis of easy magnetization is chosen in the tape running direction so that i can be extremely high, J: Yes.

According to the embodiment shown in FIG. 8, since the axis of easy magnetization is oriented in the tape running direction, there is no need for annealing. Therefore, an organic material film or the like can be used as the base.

FIGS. 9(a) to 9(d) show an example of how to make an underlayer in a high-frequency recording medium, and is an example applied to a hard disk. Substrate disk 1 shown in FIG.
0 is glass and ceramics.

It is made of a heat-stable material such as metal, and its sputtered surface is polished with high precision. Said substrate disk 10
As shown in FIG. 5B, a high permeability magnetic material such as C0-Zr-Nb is deposited on the polished surface as a thin film 11 for an underlayer by sputtering or the like. Thereafter, as shown in FIG. 3C, the material is heated in a furnace 12 to anneal at a high temperature to improve its magnetic properties. The above annealing temperature is approximately 400'C for a Co-Zr-Nb film, but this annealing temperature T
A is set in the range T'X>TA>TC, where TC is the Curie humidity of the base material and TX is the crystallization temperature. After annealing, a perpendicularly magnetized film 13 of Co--Cr or the like is deposited on the underlayer thin film 1!111 by sputtering or the like, as shown in FIG. 1(d).

Note that when the thin film 11 for the base layer is deposited by sputtering, conditions are set as shown in FIG. 10.

In FIG. 10, a substrate disk 10 installed in a sputtering apparatus is rotating in the direction of arrow Z about the center O of the disk. A pair of magnets 14A, 1 are provided at the center of the substrate disk 10 and at the outer periphery of the substrate disk 10.
4B are installed facing each other, and arrows X are marked on both sides of the substrate disk 10.
As shown in 1, magnetic flux is generated in the radial direction of the disk.

The sputter region 1i1E of the base layer is provided between the pair of magnets 14A and 14B as shown in the figure. In this way, when the substrate disk 10 is rotated while applying a magnetic field from the magnets 14A and 14B and sputtering is continued in the region E shown in the figure, the underlayer is deposited over the entire circumference of the substrate disk 10.The axis of difficult magnetization of the underlayer is As shown by the arrow Y, i occurs in the tangential direction to the disk circumference. Therefore, by annealing this, a hard magnetization axis with high magnetic permeability in the disk tangential direction and good high frequency characteristics can be obtained. An underlayer of a perpendicular magnetic recording medium that can be used satisfactorily even in high frequency bands can be obtained.

〔Effect of the invention〕

According to the present invention, a composite magnetic recording having a perpendicularly magnetized film made of a magnetic material having an axis of easy magnetization in a direction perpendicular to the film surface and an underlayer made of a high magnetic permeability magnetic material provided on the back surface of the perpendicularly magnetized film A composite perpendicular magnetic head comprising a medium, a main magnetic pole made of a high permeability magnetic thin film arranged on one side of the composite magnetic recording medium and wound with a wire, and an auxiliary magnetic pole made of a magnetic block. By using these in combination, recording sensitivity can be improved when the magnetic permeability of the underlayer of the recording medium is increased, and the underlayer has magnetic anisotropy in a plane parallel to the recording surface of the recording medium. As a result, it is possible to provide a perpendicular magnetic recording and reproducing device that can perform sufficiently good recording and reproducing in the audio or video band.

[Brief explanation of the drawing]

Figures 1 to 3 are schematic diagrams showing examples of various perpendicular magnetization heads, Figure 4 is a sectional view of a composite magnetic recording medium, and Figures 5 to 1.
Figure 0 is a diagram showing the configuration of an embodiment of the present invention, Figure 5 is a configuration diagram showing a combination of a composite magnetic recording medium and a composite perpendicular magnetic head, and Figure 6 is a diagram showing the combination of a composite perpendicular magnetic head. Figure 7 is a characteristic diagram showing the relationship between the relative magnetic permeability of the underlayer and the magnetic flux density in a composite magnetic recording medium when a composite magnetic recording medium is used, compared to when other types of magnetic heads are used. FIG. 8 is a schematic diagram showing the means for forming an underlayer of a low frequency recording medium. FIGS. 9(a) to (d>) and FIG. 10 are high frequency 1 is a diagram illustrating a base layer forming means of a recording medium for use. 1... Main magnetic pole, 2... Winding wire, 3... Recording medium, 4
...Auxiliary magnetic pole, 6...Composite magnetic recording medium, 6a...
・Nonmagnetic base, 6b... Underlayer, 6G, 13...
Vertical magnetic head removal, 7... Composite vertical magnetic head, 8...
・Roll tape, 9A, 9B, 14A, 14B... Magnet, 10... Substrate disk, 11... Thin film,
12...furnace. Applicant's representative Patent attorney Takehiko Suzue Figure 1 Figure 2 Figure 3 Figure 6 Figure 1--pz difference 1. Figure 7 Figure 8 Figure 9 (a) 4.1゜1 Figure 10

Claims (4)

[Claims] (1) A perpendicularly magnetized film made of an I magnetic material whose axis of easy magnetization exists in a direction perpendicular to the film surface, and an underlayer made of a smooth high permeability magnetic material provided on the side of this perpendicularly magnetized film. A main magnetic recording medium consisting of a composite magnetic recording medium and a high magnetic permeability FF-I thin film distributed and wound on one side of the composite magnetic recording medium.
←Equipped with a composite perpendicular magnetic head formed by magnetically coupling an auxiliary body block made of a dotted-eye bioblock, , a perpendicular magnetic recording/reproducing device in which the magnetic anisotropy in a plane parallel to the recording surface of the recording medium is expressed as '1.'i i!Q'. (2) The perpendicular magnetic recording according to claim 1, wherein the single composite magnetic recording medium is a magnetic tape in which the axis of easy magnetization of the underlayer is in the longitudinal direction of the tape. playback device. (3) The perpendicular magnetic recording and reproducing medium according to claim (1), wherein the composite magnetic recording medium is a magnetic 5R disk in which the hard magnetization axis of the underlayer is in the tangential direction of the disk circumference. Pi shield. (4) The underlayer is an amorphous film mainly composed of Co-7r-Nb.
A vertical recording/reproducing device according to claim (1) or (2) or (3).