JPH0628611A - Magnetic head and its production - Google Patents

Abstract

PURPOSE:To provide the magnetic head having excellent magnetic recording and reproducing characteristics by ingeniously utilizing the magnetic anisotropy of ferrites constituting magnetic cores. CONSTITUTION:This magnetic head has two pieces of high-permeability magnetic materials 32 facing each other via a working gap 33. These high-permeability magnetic materials 32 have notches so as to narrow the width of the working gap near the gap. At least one of the high-permeability magnetic materials 32 consist of the single crystal Mn-Zn ferrites and the {110} faces of at least one piece of the single crystal Mn-Zn ferrites are paralleled nearly with main magnetic path-forming surfaces; in addition, the magnetic head is so constituted that the angle theta formed by the <100> direction existing within the {110} face and the working gap forming surface is made to be 5 to 40 deg. or 80 deg. to 120 deg.. Glass 34 is stuck by melting to the notches to improve the reproduced outputs.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head for a magnetic recording device (hereinafter referred to as a magnetic head), and more specifically, two high-permeability magnetic bodies are provided on a surface facing a magnetic recording medium via an operating gap. The present invention relates to a magnetic head having a magnetic core facing each other and at least one of which is made of single crystal ferrite, and a method for manufacturing the same.

[0002]

2. Description of the Related Art The demand for advanced magnetic recording technology, especially for high density magnetic recording, is extremely strong today. In order to meet this demand, it is a major issue to improve the coercive force, the magnetic flux density, and the noise of the magnetic recording medium, and to greatly improve the recording characteristics and reproducing sensitivity of the magnetic head.

The present invention has been achieved as a result of intensive studies to solve the above problems, and provides a magnetic head having excellent recording and reproducing characteristics as compared with a conventional magnetic head of the same kind. is there.

At present, the magnetic heads that are widely used are
For example, as shown in FIG. 1, the blocks 11 and 11 ′ made of a magnetic material with high magnetic permeability are joined to the magnetic core formed by joining the blocks 11 and 11 ′ through the operating gap 12 so that the coil winding window 10 is formed. It is configured by winding 13 '. In particular, it is generally well known that when a single crystal ferrite is used as a high magnetic permeability magnetic material forming the magnetic core, a magnetic head having excellent high frequency characteristics and excellent wear resistance can be obtained. As the above-mentioned single crystal ferrite, cubic Mn-Zn ferrite is usually used.
The magnetic anisotropy in which the 100> axis direction or the <111> axis direction is the easy axis of magnetization is shown.

By the way, there are many unexamined points about how to arrange the above-mentioned crystal axis direction in the magnetic core of the magnetic head, and there is still no definite guiding principle.

It goes without saying that the performance of the magnetic head depends on the distribution of the magnetic resistance inside the magnetic core. However, it is difficult to obtain detailed information on the state of changes in magnetic characteristics due to surface processing of ferrite, especially processing near the working gap that strongly controls the characteristics of the magnetic head. It is extremely difficult to predict what kind of magnetic resistance distribution will be realized by arranging the azimuths. Furthermore, even if it is predictable, it is important to calculate how the magnetic anisotropy axis should be arranged in the working gap for the best read / write characteristics. It is still extremely difficult to use. It can be said that the main cause of the extremely unclear nature of the desired arrangement of the crystal axes in the magnetic core lies in this point.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a magnetic head having particularly excellent magnetic recording / reproducing characteristics by making good use of the magnetic anisotropy of ferrite constituting a magnetic core. .

[0008]

In order to achieve the above object, a magnetic head according to the present invention has two high-permeability magnetic bodies which face each other through an operating gap. It has a notch so as to narrow its width in the vicinity of the action gap, at least one of the high-permeability magnetic bodies is made of single crystal Mn-Zn ferrite, and at least one of the single crystal Mn-Zn ferrite {110} Angle between the <100> direction existing in the {110} plane and the action gap formation surface while making the plane substantially parallel to the main magnetic path formation surface.
(Θ is assumed to be a vector heading to the recording medium facing surface on the working gap forming surface, and the end of the vector is centered on the beginning of the vector and extends from the gap forming surface to the inside of the high magnetic permeability magnetic body. When rotating on the main magnetic path forming surface, the sweeping rotation angle of the vector is positive) is 5 ° to 40
Or 80 ° to 120 °, and for applying tensile stress to the single crystal Mn-Zn ferrite, at least glass having a high magnetic permeability is formed on the surface of the notch near the side surface of the working gap. The reproduction output is improved by melting and adhering.

[0009]

Function: The single crystal Mn-Zn ferrite is -2 x 10
^It has a magnetocrystalline anisotropy constant of ⁴ to 1 × 10 ⁴ erg / cc, and more preferably −1.5 × 10 ⁴ to 8 ×.
It has a magnetocrystalline anisotropy constant of 10 ³ erg / cc. In the magnetic head according to the present invention, at least the glass having a shrinkage ratio lower than that of the ferrite is melt-adhered to the ferrite surface (excluding the surface facing the magnetic recording medium and the operation gap forming surface) in the vicinity of the operating gap portion, so that the ferrite A tensile stress is generated in the inside, and the presence of this tensile stress controls the magnetic anisotropy of the ferrite, and the controlled magnetic anisotropy is utilized to enhance the recording / reproducing characteristics. However, if the crystal magnetic anisotropy constant of the ferrite is out of the above range, the desired magnetic anisotropy cannot be obtained even in the presence of tensile stress, and the effect of the present invention cannot be expected.

In order to induce uniaxial magnetic anisotropy in the ferrite surface by applying tension to the surface, the surface must be parallel to the {110} plane.
When compressive stress is applied, uniaxial anisotropy is also induced on other surfaces, but when this stress is applied by glass that has been melt-deposited, tensile stress acts on the glass and glass cracking is likely to occur. The ferrite surface, which is impractical and on which glass is melted and adhered, is mainly the main magnetic path forming surface, so in the end, in order to induce uniaxial magnetic anisotropy in the surface by applying tension to the ferrite surface. It is necessary to make the main magnetic path forming surface substantially parallel to the {110} surface. The reason why the {110} plane of the single crystal Mn-Zn ferrite in the magnetic head of the present invention is made substantially parallel to the main magnetic path forming plane is as described above.

Further, the vicinity of the side surface of the working gap means that
Mainly a side surface substantially parallel to the main magnetic path forming surface, and a region having a radius of about d to a radius of about 10 with a line of intersection of the magnetic recording medium facing surface and the working gap forming surface as the center.
The area of d is indicated. However, d is the depth of the working gap forming surface and is shown in FIG. By melting and adhering glass to the side surface in this extreme range from the working gap forming surface, the magnetic anisotropy of ferrite can be controlled so that the performance of the magnetic head is sufficiently improved. The vicinity of the side surface of the operating gap corresponds to the side surface of the well-known magnetic core cutout portion of the magnetic head.

The magnetic head according to the present invention has two high-permeability magnetic bodies which face each other through an operating gap, and at least one of them has a single crystal Mn-Zn ferrite. As described above, single crystal Mn-
Since Zn ferrite is excellent as a magnetic core material, it is usually more desirable that both of the two high-permeability magnetic bodies are single crystal Mn-Zn ferrites. Similarly, in the magnetic head according to the present invention, the single crystal M
At least one of the n-Zn ferrites must satisfy the above crystal orientation condition, but two single crystals M
It is more preferable that all of the n-Zn ferrites satisfy such crystal orientation conditions.

As is well known, the glass that melts and adheres near the side surface of the working gap is usually filled in the notch of the magnetic core provided in this portion. Originally, the notch was provided for the purpose of reducing the track width.

The angle θ is 5 ° to 40 ° or 80 ° to
When the angle is in the range of 120 °, the recording / reproducing characteristics of the magnetic head according to the present invention are superior to those of the conventional one, but when the angle θ is 10 ° to 35 ° or 85 ° to 115 °, the recording is further excellent. A reproduction characteristic is obtained, and the angle θ is about 2
The best results are obtained at 5 ° or about 100 °. Angle θ is 5 ° to 40 ° or 80 ° to 120
If it is out of the range, only recording / reproducing characteristics equal to or lower than those of the conventional one can be obtained.

Single crystal Mn used by the shrinkage of the glass
If it is lower than -Zn ferrite, excellent recording and reproducing characteristics can be expected, but if the glass shrinkage is equal to or higher than that of ferrite, this cannot be expected. If the difference between the shrinkage ratio of the glass and the shrinkage ratio of the ferrite is 1.3 × 10 ⁻⁶ or more, cracks may occur in the vicinity of the working gap, and a decrease in yield in magnetic head manufacture is expected. . Therefore, it is more preferable that the shrinkage of glass is lower than that of ferrite, and the difference between the two is less than 1.3 × 10 ⁻⁶ . Also,
The glass may have any composition as long as it has a shrinkage ratio within a predetermined range and satisfies other well-known design conditions.

In view of the situation of the prior art described above, the present invention prototypes a large number of magnetic heads which use single crystal Mn-Zn ferrites of various compositions and have various crystal axis orientations, and the recording / reproducing characteristics and working gaps of the prototype magnetic heads. It is constructed based on a novel finding by the inventors of the present invention obtained as a result of studying the relationship with the crystal axis arrangement state of ferrite in the vicinity, and particularly in the ferrite near the working gap part of the magnetic core. Recording and reproducing by optimizing the orientation angle of the easy axis of magnetization on both sides of the working gap while simplifying the distribution of the easy axis of magnetic anisotropy in the vicinity of the working gap by making tensile stress act on It is intended to provide a magnetic head having excellent characteristics.

As described above, the performance of the magnetic head is strongly governed by the magnetic characteristics in the vicinity of the working gap. For example, as in a magnetic head in a recent home video tape recorder, the track width is extremely narrowed and the mechanical strength is maintained, and the core width except the working gap is reduced in order to reduce the total magnetic resistance of the magnetic core. In the magnetic head as shown in FIG. 2, which has a thickness as thick as possible, the tendency of the performance of the magnetic head to be strongly controlled by the magnetic characteristics in the vicinity of the operating gap becomes stronger and stronger. Therefore, the characteristics of the magnetic head should change greatly depending on the direction of the easy axis of magnetization in the vicinity of the operating gap, that is, the orientation of the crystal axis of the single crystal ferrite. In FIG. 2, 20 is a coil winding window, 21 and 21 'are ferrite blocks, 22 is an operating gap, 23 and 23' are coils, and 24 is filled glass.

Incidentally, although the single crystal Mn-Zn ferrite used in the magnetic head usually has a small average magnetostriction constant, it is represented by λ ₁₀₀ and λ ₁₁₁ <100.
The magnetostriction coefficients in the> direction and the <111> direction have different positive and negative polarities, but both are in the order of 3 to 10 × 10 ⁻⁶ . On the ferrite surface processed by a usual processing method, that is, an outer peripheral slicer, a dicer, a wire saw, etc., a work-affected layer having a depth of several hundreds nm to several μm is formed, which causes tensile stress inside the ferrite. It is known to occur. However, detailed data on how much stress actually occurs are not available. Further, the recording medium facing surface of the magnetic head is usually ground with a polishing tape or a wrap, and the recording medium facing surface is not only used in the magnetic tape device but also in the magnetic head floating magnetic disk device. Since the contact with the recording medium is not avoided, the processing effect by these cannot be ignored. However, depending on the magnitude of the crystal magnetic anisotropy of the ferrite used, the magnetic anisotropy axis in the vicinity of the working gap in the working state of the magnetic head composed of single crystal Mn-Zn ferrite is usually used. The true state of the distribution is beyond speculation.

In fact, by the above processing method, a single crystal Mn-Zn ferrite (Fe ₂ O ₃ ;
54 mol%, MnO; 27 mol%, ZnO; 19 mol%
Disk having a composition of 1.17 × 10 ^-5 deg ^-1 ) was prepared, and the magnetic permeability in the plane was measured. As a result, it was found that the magnetic permeability had a remarkable difference of 180 ° symmetry. It was shown that the magnetic permeability was maximum, and the direction of the maximum magnetic permeability changed depending on the measurement frequency.

That is, on the low frequency side, the above {110}
The magnetic permeability is maximum in the <110> direction in the plane and minimum in the direction perpendicular thereto, that is, in the <100> direction, whereas this relationship is reversed on the high frequency side. This is
When viewed in the {110} plane, the ferrite disk shows that the easy axis of magnetization is induced in the <110> direction in the plane. By the way, the magnetocrystalline anisotropy constant K ₁ of the material of the above-mentioned ferrite disk is positive and 2 to 4 × 10 ³ erg.
/ Cc, and if there is no processing effect, then <110
The <100> direction, which is perpendicular to the> direction, should be the easy axis of magnetization. Further, the maximum and minimum ratios of magnetic permeability observed in the above ferrite disk are, for example, 3 to 5 MHz.
2 shows a value of 2 to 5 in the frequency region, and if a magnetic head as shown in FIG. 2 is produced by using the above-mentioned material and the above-mentioned processing method, naturally the orientation in the direction of the crystal axis in the working gap portion is obtained. The recording / reproducing characteristics should change significantly depending on the method. Based on the above knowledge, a magnetic head as shown in FIG. 3 and Table 1 is manufactured using a single crystal ferrite block having the same composition as the above single crystal Mn—Zn ferrite, and a coil is wound around the magnetic core. The recording / reproducing characteristics of were measured. That is, the main magnetic path forming surface 32 of the magnetic core having the specifications as shown in Table 1,
32 ′ is a {110} plane, and a magnetic head using a magnetic core in which the angle θ between the <100> direction included in the main magnetic path forming surface and the working gap forming surface 33 is variously changed. The recording / reproducing characteristics were comparatively evaluated.

[0021]

[Table 1]

In FIG. 3, reference numeral 34 designates filled glass, 36,
36 'is a ferrite block, and 35 is a coil winding window. In the manufacture of these magnetic heads, glass 34 was buried on both sides of the operating gap for the purpose of protecting the operating gap, but the filled glass 34 is approximately the same as the single crystal Mn-Zn ferrite having the above composition. A glass having a coefficient of thermal expansion of about 1.05 × 10 ^-5 deg ^-1 having a shrinkage ratio of 1.0 was used so that stress due to the difference in shrinkage ratio between the ferrite and the filled glass was not generated inside the ferrite. A method for preparing the filling glass 34 will be described in Examples below. FIG. 4 shows the evaluation results of the recording / reproducing characteristics of the magnetic head manufactured in this way. FIG. 4 shows an angle formed by the <100> direction existing in the {110} plane existing in parallel with the main magnetic path forming surfaces 32 and 32 'and the working gap forming surface 33, that is, θ (degree) in FIG. 3 and the magnetic head. 3 is a graph showing the relationship with the head output (indicating relative output and being an arbitrary unit). The measurement in this case was performed at a recording wavelength of 1.4 μm and a frequency of 4 MHz.

As is clear from FIG. 4, the characteristic slightly deteriorates when θ is around 60 °, but the head output does not depend much on θ for other θ. This means that for some reason, the magnetic anisotropy that ferrite near the working gap should have should be averaged.

The manufacturing process of the above-mentioned prototype head is a process which is generally carried out except for the crystal orientation, and it is also possible to use the filling glass 34 having a shrinkage ratio similar to that of ferrite. It is quite common sense. Therefore, in the single crystal ferrite magnetic head manufactured by the conventional technique, the magnetic anisotropy that the single crystal ferrite should have is not fully utilized.

The inventors of the present invention thus intentionally generate an internal stress in the vicinity of the working gap so that the magnetic anisotropy in the vicinity of the working gap becomes apparent, and further By optimizing the orientation of the axes, the basic idea of fully utilizing the effect of magnetic anisotropy and improving the recording / reproducing characteristics of the magnetic head has been obtained.

[0026]

The present invention will be described in more detail with reference to the following examples.

Based on the above basic idea, the same magnetic head as the prototype head is manufactured except that the filling glass 34 has various thermal expansion coefficients (that is, various shrinkage rates), and the main magnet is manufactured. Relationship between the angle formed by the <100> direction existing in the {110} plane existing in parallel with the path forming surfaces 32 and 32 'and the working gap forming surface 33, that is, θ in FIG. 3 and the recording / reproducing output of the magnetic head. I asked. Thermal expansion coefficient α of the used filled glass (from room temperature to 350
The average up to ° C is 74 x 10 ^-7 deg ^-1 (-1.3 x 10)
^-6 ), 80 × 10 ^-7 deg ^-1 (-1.3 × 10 ^-6 ), 87 ×
10 ^-7 deg ^-1 (-0.7 × 10 ^-6 ), 96 × 10 ^-7 deg
^-1 (-0.4 × 10 ^-6 ), 101 × 10 ^-7 deg ^-1 (-0.
2 × 10 ⁻⁶ ), 105 × 10 ⁻⁷ deg ⁻¹ (0), and the fixing temperature is about 450 ° C. in each case. The value in parentheses is the value obtained by subtracting the shrinkage ratio of the ferrite from the shrinkage ratio of the filled glass β
Is.

The filling glass 34 is ZnO; 27%, Na
₂ O; 8%, BaO; 8%, SiO ₂ ; 16%, Al
₂ O ₃ ; 4%, B ₂ O ₃ ; 37%, and α is 7
4 × 10 ⁻⁷ deg ⁻¹ , β −1.3 × 10 ⁻⁶ glass,
ZnO; 29%, Na ₂ O; 3%, K ₂ O; 8%, Ba
O; 14%, CaO; 4%, SrO; 4%, SiO ₂ ;
9%, B ₂ O ₃ ; 23%, TiO ₂ ; 5%, Li ₂ O and impurities; 1%, and α is 107 × 10 ⁻⁷
It is a mixture of glass having a degree of deg ^-1 and β of 0.1 × 10 ^-6 in such a ratio that the values of α and β are obtained. The glass composition is shown by weight%.

The measurement results are shown in FIGS. FIG. 5 shows head output (relative output, which is an arbitrary unit) and θ.
It is a graph showing the relationship with (degree), 51 is α is 87
In the case of using the glass of × 10 ^-7 deg ^-1 (β is -0.7 × 10 ^-6 ), 52 is the value when the glass of α is 105 × 10 ^-7 deg ^-1 (β is 0) is used. It is a curve. FIG. 6 is a graph showing the relationship between the head output (relative output, which is an arbitrary unit) and α and β when θ is 25 °. The recording / reproducing characteristics shown in FIGS. 5 and 6 have a recording wavelength of 1.4 μm.
m, frequency 4 MHz.

In the present embodiment, α is selected so that the stress at the interface between the side surface of the working gap and the filled glass, which is caused by the temperature change during the welding of the filled glass, is tensile with respect to the ferrite side. The magnetic anisotropy in the vicinity of the side surface of the working gap portion was enhanced by further promoting the stress due to the work-affected layer of ferrite near the side surface.

Contrary to the expectation, the θ dependence of the recording / reproducing characteristics of the magnetic head according to this embodiment shows a very clear four-fold symmetry. Further, more importantly, by emphasizing the magnetic anisotropy in the vicinity of the working gap portion and setting θ in an appropriate range, a magnetic head having extremely good characteristics that could not be obtained by the conventional technique is obtained. It means to get it. The recording / reproducing characteristics shown in FIG. 5 have a recording wavelength of 1.4.
.mu.m and frequency of 4 MHz, but such .theta. dependency is also observed in the recording wavelength range of 1 to 20 .mu.m and frequency range of 0.3 to 6 MHz, and the ratio of the maximum value to the minimum value of the head output changes slightly. Except for this, it is almost the same as FIG. Also, the coercive force is 300 to 17000e.
When various recording media of No. 1 were used, similar characteristics were obtained.

As is clear from FIG. 5, θ is 5 ° to 40 °
Good recording / reproducing characteristics can be obtained when the angle is 80 ° or 80 ° to 120 °, but more preferable θ is about 10 ° to 3 °.
The best results are obtained when θ is about 25 ° or 100 °, or 5 ° or 85 ° to 115 °. Note that θ that gives the best results above is 2
The magnetic head near 5 ° and the magnetic head with θ approaching 100 ° are symmetrical with respect to the value of Q. That is, in the frequency range of 1 to 6 MHAz, Q has a θ of 2
The maximum value is obtained near 5 °, and the minimum value is obtained when θ approaches 100.

Further, among the magnetic heads in this embodiment, the magnetic head using the filled glass having α of 74 × 10 ^-7 deg ^-1 (β is 1.3 × 10 ^-6 ) has cracks near the working gap. If it is lower than this, the yield of manufacturing the magnetic head will be reduced.

The side surface of the working gap of the magnetic head in this embodiment (filling glass 34 and ferrite block 36,
(The interface with 36 ′) The tensile stress σ estimated to occur in the center is at most ² to 3 Kg / mm ² , and the magnetostriction constants λ ₁₀₀ and λ of Mn—Zn ferrite that is usually used are
₁₁₁ is −5 × 10 ⁻⁶ to ⁻¹⁰ × 10 ⁻⁶ and 3 × 10 ^{−6 to} 7 × 10 ⁻⁶ , respectively. In the {110} plane of the single crystal ferrite having such a magnetostriction constant, the above 2 to 3K
By applying a tensile stress of g / mm ² , the {11
In order to make the <100> direction in the 0} plane the magnetic easy axis, the crystal magnetic anisotropy constant K ₁ of the _single crystal ferrite must be within a certain range. Further, in principle, it depends on whether the K ₁ is positive or negative. That is, in the case of K ₁ > 0, in the range of K _{1 such} that K ₁ <3 | λ ₁₁₁ σ |, and in the case of K ₁ <0, | K ₁ | <3 | (λ ₁₀₀ −λ ₁₁₁ ) σ | In the range of K ₁ , the above effect will be specially stipulated. Λ described above
_When the values of ₁₀₀ , λ _{11 1} and σ are used, the range of the value of K ₁ in which the above effect is expected is −2 × 10 ⁻⁴ erg / cc to 1 × 1.
It becomes 0 ⁴ erg / cc. This value range of K ₁ neglects the existence of the anisotropy constant K ₂ which is said to be small in ordinary ferrite. Considering the existence and safety of K ₂ , the more preferable range of K ₁ is -1.5.
× 10 ⁴ erg / cc to 8 × 10 ³ erg / cc. M
K ₁ of n-Zn ferrite tends to increase with an increase in the amount of Fe ₂ O ₃ when the composition of Fe ₂ O ₃ is around 50 mol%.

As is clear from FIG. 6, the effect of the present invention can be recognized if the value of β is negative, but −0.2 × 1
If it is 0 ^-6 or less, more preferable results can be obtained. Further, as described above, when the value of β is -1.3 × 10 ^-6 or more, no crack is observed and good results are obtained. Therefore, the more preferable range of the value of β is −0.2 × 1.
It is 0 ⁻⁶ to −1.3 × 10 ⁻⁶ .

The measurement results shown in FIGS. 4, 5 and 6 are: Fe ₂ O ₃ ; 54 mol%, MnO; 27 mol%, Zn
The magnetic heads were obtained using a single crystal Mn-Zn ferrite having a composition of O: 19 mol%, but the same experiment as above was performed using single crystal Mn-Zn ferrites of various compositions shown in Table 2. As a result, it was possible to obtain a magnetic head having a recording / reproducing characteristic equal to or higher than the highest performance obtained by the conventional technique in the above range of θ and β in the case of ferrite having any composition. In addition,
The value of K ₁ has been tested at -1.5 × 10 ⁴ to 2 × 10 ³ erg / cc, but in the case of -1.5 × 10 ⁴ erg / cc, it is different from the case of 8 × 10 ³ erg / cc. Since it has almost the same effect of applying internal stress, K ₁ was −1.5 × 10 ⁴ to 8 × 10 ³ erg / cc in an experiment using ferrite having the composition shown in Table 2.
It can be said that good results can be expected in the range of.

[0037]

[Table 2]

The characteristics of the magnetic head described above were obtained for the magnetic head in which the squeezing angle φ of the winding window 35, the squeezing length of the working gap and l in FIG. 3 are limited to those shown in Table 1. As shown in Table 3, magnetic heads having various values of φ in the range of 60 ° to 30 ° and l in the range of 50 to 500 μm were tested. As a result, head output characteristics having the same θ dependence as described above were obtained. was gotten.

[0039]

[Table 3]

Further, in the magnetic head used for the above-mentioned measurement, as shown in FIG. 3, the shape of the winding window 35 is left-right asymmetric, but this is made symmetrical as shown in FIG. The measurement results obtained for the magnetic head were similar to the above. In FIG. 7, 70 is a winding window, 71 and 71 'are ferrite blocks, 72 is a working gap, 7
3 and 73 'are coils, and 74 is filled glass.

Further, in the magnetic head of the present invention, when the main magnetic path forming surface is constituted by the true {110} plane as described above, the excellent effect as described above can be obtained. Even in a magnetic head whose surface is tilted by about ± 15 ° with respect to {110}, almost the same characteristics as described above were obtained.

Further, in the above-mentioned embodiments, all the magnetic bodies facing each other through the working gap are Mn-Zn single crystal ferrites, and the crystal axes of the single crystals are substantially symmetrical with respect to the gap forming surface. However, as is clear from the above description, even if the orientation of the crystal axes is asymmetric, the angle θ between the <100> direction of both crystals and the cap forming surface is limited to the above range. Therefore, the same effect can be expected. Further, the effect of the present invention is expected when the above θ condition is satisfied only for one ferrite, or when only one of the magnetic bodies is a single crystal Mn—Zn ferrite and the θ condition is satisfied. it can.

[0043]

As described above, according to the present invention, the magnetic anisotropy of the ferrite constituting the magnetic core can be skillfully utilized, and a magnetic head having excellent magnetic recording and reproducing characteristics is provided. be able to.

[Brief description of drawings]

FIG. 1 is a perspective view showing the structure of a conventional magnetic head.

FIG. 2 is a perspective view showing the structure of a conventional magnetic head.

FIG. 3 is a front view and a plan view showing a magnetic head according to an embodiment of the present invention.

FIG. 4 is a graph showing a relationship between θ and head output of a magnetic head using glass having a shrinkage ratio similar to that of ferrite.

[Fig. 5] Difference of shrinkage ratio β with ferrite is -0.7 × 10
⁶ is a graph showing the relation between θ and head output of a magnetic head using ^-6 or 0 glass.

FIG. 6 is a graph showing the relationship between β or α and the head output of a magnetic head in which θ is 25 °.

FIG. 7 is a perspective view showing a magnetic head according to another embodiment of the present invention.

[Explanation of symbols]

32, 32 '... Main magnetic path forming surface, 33 ... Operating gap forming surface, 34 ... Filled glass, 35 ... Coil winding window, 36,
36 '... ferrite block, 51 ... β is -0.7 × 1
If 0 ^-6, if 52 ... beta is 0, 70 ... coil window, 72
… Working gap, 74… Filled glass.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Nobuyuki Sugishita 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Inside the Hitachi, Ltd. Institute of Industrial Science (72) Inventor Yoshihiro Shiroishi 1-280, Higashi Koikeku, Kokubunji, Tokyo Stock Hitachi, Ltd. Central Research Laboratory (72) Inventor Tsuyoshi Kimura 1-280, Higashi Koikeku, Kokubunji, Tokyo Hitachi Ltd. Central Research Center (72) Inventor, Kosei Shinagawa 1-280, Higashi Koikeku, Kokubunji, Tokyo Hitachi Ltd. In the Central Research Laboratory (72) Climbing Kumasaka, Inventor 1-280 Higashi Koikekubo, Kokubunji City, Tokyo Inside Hitachi Central Research Laboratory, Hitachi Ltd.

Claims (7)

[Claims] 1. A high-permeability magnetic body having two high-permeability magnetic bodies which face each other through an operating gap, the high-permeability magnetic body having a notch so as to narrow its width in the vicinity of the operating gap, At least one of the high-permeability magnetic bodies is made of single crystal Mn-Zn ferrite, and the {110} plane of at least one single crystal Mn-Zn ferrite is made substantially parallel to the main magnetic path forming plane and the {110} plane is formed. The angle θ between the <100> direction existing in the plane and the surface on which the working gap is formed (θ is assumed to be a vector toward the recording medium facing surface on the surface on which the working gap is formed, and the end of the vector is the vector). When the main magnetic path forming surface is rotated from the gap forming surface toward the inside of the high permeability magnetic body about the start end of the vector, the sweeping angle of the vector is positive. ° or 80
A magnetic head, characterized in that it is configured to be at an angle of 120 ° to 120 °, and glass is melted and adhered to the notch to improve the reproduction output. 2. The magnetic head according to claim 1, wherein the angle θ is 10 ° to 35 ° or 85 ° to 115 °. 3. The magnetic head according to claim 1, wherein the angle θ is about 25 ° or about 100 °. 4. The value obtained by subtracting the shrinkage rate of the ferrite from the shrinkage rate of the glass when the temperature is lowered from the glass fixing temperature to room temperature is -0.2 × 10 ^-6 to -1.3 × 10 ^-6 . The magnetic head according to claim 1, 2, or 3 characterized in that there is. 5. The crystal magnetic anisotropy constant K ₁ of the single crystal Mn—Zn ferrite is −2 × 10 ⁴ to 1 × 10 ⁴ erg / cc.
Claims 1 and 2 characterized in that
The magnetic head according to item 3, item 3 or item 4. 6. The crystal magnetic anisotropy constant K ₁ of the single crystal Mn-Zn ferrite is -1.5 × 10 ⁴ to 8 × 10 ³ erg /
The magnetic head according to claim 1, 2, 3, or 4, which is cc. 7. A high-permeability magnetic body having two high-permeability magnetic bodies which face each other through an operating gap, the high-permeability magnetic body having a notch so as to narrow its width in the vicinity of the operating gap. A method of manufacturing a magnetic head, wherein at least one of the high-permeability magnetic bodies is made of single-crystal Mn-Zn ferrite, wherein at least one {110} plane of the single-crystal Mn-Zn ferrite is substantially the main magnetic path formation plane. Parallel to the {110}
The angle θ between the <100> direction existing in the plane and the surface on which the working gap is formed (θ is assumed to be a vector toward the recording medium facing surface on the surface on which the working gap is formed, and the end of the vector is the vector). When the main magnetic path forming surface is rotated from the gap forming surface toward the inside of the high permeability magnetic body around the start end of the vector, the sweeping angle of the vector is set to be positive)
Is set to 5 ° to 40 ° or 80 ° to 120 °, the glass is melted and adhered to the cutout portion, and tensile stress is generated in the ferrite in the vicinity of the working gap, so that the magnetic anisotropy is increased. And a reproduction output is improved by controlling the magnetic field.