JPH03219407A - Magnetic head - Google Patents

Abstract

PURPOSE:To eliminate magnetic strain by providing soft magnetic layers which are exposed in the tip opposite surfaces of a magnetic head core which has the tip opposite surfaces and recessed parts formed behind the opposite surfaces and forming a gap between the core opposite surfaces. CONSTITUTION:The ferrite core 1 which has the tip opposite surfaces 1a and 1a' and the recessed parts 1b and 1b' formed behind the opposite surfaces is coupled and integrated. The soft magnetic layers 2 and 2' and SiO2 layers 3 and 3' are formed on the tip opposite surfaces 1a and 1a' and recessed parts 1b and 1b' of the core 1, the soft magnetic layers 2 and 2' face each other, and the gap is constituted between the soft magnetic layer opposite surfaces. The SiO2 layers 3 and 3' are coupled with glass filling parts 5 and 5'. The soft magnetic layers 2 and 2' have a composition formula FeaBbNc. In the formula, (a), (b), and (c) are atomic % and B is at least one kind among Zr, Hf, Ti, Nb, Ta, V, Mo, and W; and 0<b<=20.0 and 0<c<=22 hold (except b<=7.5 and c<=5), thereby obtaining the composite magnetic head.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention uses a soft magnetic layer having high saturation magnetic flux density and high frequency magnetic permeability as the core material of the head.

The present invention relates to a magnetic head for high-density recording and reproduction.

[Background of the Invention] For example, in magnetic recording and reproducing devices such as audio tape recorders and VTRs (video tape recorders), the density and quality of recording signals are increasing, and it is necessary to respond to this increase in recording density. Fe is added to magnetic powder as a magnetic recording medium.
, Co, Ni, or other metals or alloys were used. A so-called metal tape or two ferromagnetic metal materials were deposited directly onto the base film by vacuum thin film formation technology. So-called vapor deposition tapes have been developed and put into practical use in various fields.

[Prior art and problems to be solved by the invention] By the way, in order to exhibit the characteristics of a magnetic recording medium having a predetermined coercive force, the core material of the magnetic head must have a high saturation magnetic flux density. If the same magnetic head is to be used for reproduction, it is also required to have high magnetic permeability.

Conventionally, sendust alloy (Fe-St-Ai!

B s z 10 KG), Co-based amorphous alloys, etc. have been used, but Sendust alloy has a large internal stress in the film and crystal grains tend to grow, making it difficult to thicken the film.

Also, the saturation magnetic flux density Bs is about IDKG.

4. The saturation magnetic flux density Bs is insufficient for higher density recording. In addition, Co-based amorphous alloys have good properties and can be manufactured with high saturation magnetic flux density Bs, but because they crystallize at about 450°C, glass bonding cannot be performed at high temperatures when forming heads, and sufficient bonding strength cannot be obtained. The problem was that it couldn't be done.

Other soft magnetic materials include iron nitride, which is generally formed into a thin film by ion beam evaporation or sputtering using iron as a target in a nitrogen-containing atmosphere. However, this soft magnetic thin film has a problem in that its coercive force increases significantly due to heating during glass bonding, etc., resulting in insufficient stability of characteristics.

Japanese Unexamined Patent Publication No. 83-299219 describes the following soft magnetic thin film intended to improve these problems.

rFexNy Az (However, + X+ 'l+
Z represents the composition ratio as atomic %, A is SL, Aj
i.

Ta, B, Mg, Ca, Sr, Ba, Cr.

Mn, Zr, Nb, Ti, Mo, V, W, Hf.

Represents at least one of Ga, Ge, and rare earth elements. ), and its composition range is 045≦y≦5.0 0.5≦2≦7,5 x+y+z=lo.

A soft magnetic thin film characterized by: However, the soft magnetic thin film described in JP-A-83-299219 cannot be used for manufacturing magnetic heads that require a heating process such as a glass bonding process because the coercive force inevitably increases due to heating. is not desirable.

Furthermore, since it does not have -axis anisotropy, it has the disadvantage that magnetic permeability at high frequencies cannot be increased.

Also, although it depends on the film forming conditions, numerically crystalline materials tend to become columnar crystals due to the self-shadowing effect during the film deposition process, and voids are formed at one grain boundary, so magnetically There is a tendency for the soft magnetic properties to deteriorate due to discontinuity. This self-shadowing effect becomes particularly noticeable when there are steps on the base or when the film is thick, such as when manufacturing a magnetic head, and there is a problem in that sufficient characteristics cannot be obtained.

The soft magnetic thin film described in the above-mentioned publication had the above-mentioned problems and was not suitable as a magnetic head core material.

An object of the present invention is to provide a magnetic head that improves the problems of the prior art described above.

[Means for Solving the Problems] According to the present invention, the above object can be achieved with the following magnetic head.

(2) A magnetic head core having a tip facing surface and a recess formed receding from the facing surface, a soft magnetic layer exposed at least on the facing surface, and a gap formed between the facing surfaces of the core; The soft magnetic layer is FeB Bb N
O (however, a, b, c each indicate atomic %, B is Zr,
Hf, Ti, Nb.

Represents at least one of Ta, V, Mo, and W. )
1. A composite magnetic head characterized in that the composition range is o<b≦20 and 0<c≦22 (excluding b≦7.5 and c≦5).

■ A lower soft magnetic layer, an insulating layer, a coil conductor layer, and an upper soft magnetic layer are sequentially provided on the substrate, and a magnetic gap layer that reaches the recording medium orientation plane of the head is provided between the lower soft magnetic layer and the upper soft magnetic layer. The soft magnetic layer is made of Fel Bl, Ne
(However, a, b, and c each indicate atomic %, and B is Zr.
, Hf, Ti, Nb.

Represents at least one of Ta, v, Mo, and W.

), and the composition range is o<b≦20 and 0<c≦22 (excluding b≦7.5 and c≦5). This composition range is point E,
They are shown in FIG. 1 by F, G, H, I, and J.

Preferably, the composition range is 69≦a≦93 2≦b≦15 5.5<c≦22 is within the range of This composition range is defined as points Q, L, and L.

It is shown in FIG. 1 by U and M.

More preferably, the composition range is P (91,2,7
) Q (92,5,2,5,5) R (87,7,5,5,5) S (73,12,15) T (69,12,19) U (69,9,22) V (78, 5, 19) This is the range surrounded by the line segment connecting the seven points. This composition range is shown in FIG. 1 by points P, Q, R, S, T, U, and V.

More preferably, the crystal grain size is 300 Å or less, and the soft magnetic layer has uniaxial anisotropy.

[Preferred Embodiments and Effects] The soft magnetic layer of the magnetic head of the present invention contains Fe and N, and specific additive elements B, namely Zr and Hf.

It consists of at least one element of Ti, Nb, Ta, V, Mo, and W, and these Fe and N and a specific additive element B
All three (including two or more types) are within the above-mentioned specific composition range.

When the composition range is 0, b≦20, and Q<c≦22 (excluding b≦7.5 and c≦5), preferably b≧0.5 and C≧0. .5.

This is because when b<0.5 or c<0.5, the effect of its presence may not be clear.

The additive element B exceeds 20 atomic %, or.

If N exceeds 22 atomic %, good soft magnetism cannot be obtained.

When the composition range is 69≦a≦93, 2≦b≦15, and 5.5<c≦22, better soft magnetism is exhibited.

More preferably, the composition is at the specific points P, Q, in the ternary composition coordinate system (Fe, B, N) of the three
This is the range surrounded by line segments connecting the seven points R, S, T, U, and V. Since the coercive force is particularly small in this composition range, it is suitable as a core material for a magnetic head. The most preferable range is a coercive force of 1.5.
This is a composition range showing 0e or less (even 10e or less).

When the additive element B is Zr, the preferable composition range of the soft magnetic layer is as follows.

F ed (Z re N5-e)
+*o-d77≦d≦88 0.3≦e≦0.38. Point W represents this composition range.

It is shown in FIG. 1 by x, y, z. These points W.

The x, y, and z coordinates are approximately as follows.

W (88,3,8,8゜4) X (8g, 4.5B, 7.44)Y (77,8
, 74, 14, 28) Z (77, 1!, 9.18.1) That is, in this range, Fe is contained at 77 to 88 atomic %, and the Zr content b (atomic % ) and the N content C (atomic %) c/b is approximately 1.63 to 2.
It is 33. A soft magnetic layer having this composition range has good soft magnetic properties (for example, coercive force Hc<5Oe).

The additive elements may be one or more kinds. For example, only Zr can be added, but some of the Zr (for example, 3 of the added Zr) can be added with other additive elements.
0 atoms 96) can be replaced.

Further, Fe can be replaced with one or more of Co, Ni, and Ru. For example, up to about 30 atoms and 96 atoms of Fe constituting the soft magnetic layer can be replaced.

The soft magnetic layer of the magnetic head of the present invention is obtained by obtaining an amorphous layer having the above-mentioned specific composition by, for example, a vapor phase deposition method such as RF sputtering method, and then heat-treating this amorphous layer at, for example, 350 to 650°C to obtain the above-mentioned composition. It can be formed by crystallizing part or all of the amorphous layer. Preferably, the amorphous layer is formed by heat treatment in a magnetic field to induce uniaxial magnetic anisotropy and crystallize part or all of the amorphous layer.

When forming the soft magnetic layer of the thin film magnetic head of the present invention by the method described above, there may be a difference in the initial characteristics of the formed soft magnetic layer depending on the type of substrate. It is preferable to select and manufacture.

[Example] Hereinafter, first, a manufacturing example and characteristics of a soft magnetic thin film used as a soft magnetic layer of a magnetic head of the present invention will be described in detail.

(Example 1) F eg-y Z ry (y m 5.0.10
．． An alloy target having a composition of (L L5.0 (at%)) was prepared, and each target was heated in a nitrogen-containing argon gas atmosphere containing 2.5 to 12.5 mol% nitrogen at a gas pressure of 0.
High frequency sputtering was performed under conditions of 8 Pa and input power of 200 W to obtain amorphous alloy films of various compositions. Each of these thin films was heat treated in a magnetic field to obtain soft magnetic thin films, and their saturation magnetic flux density Bs and coercive force Hc were measured.

Bs and Hc were measured using an AC BH tracer (applied magnetic field 50Hz, 250e, but if Hc > 25,
00e) (the same applies hereafter). A crystallized glass substrate (PEG3130 manufactured by CHOYA) and a single crystal sapphire substrate were used as the substrates. Further, the film thickness was approximately 0.6 μm in all cases.

These results are shown in Table 1-A. Note that Hc is expressed as a value in the easy axis direction. In addition, for some soft magnetic thin films,
Magnetic permeability μ and magnetostriction at 5 MHz were measured. Magnetostriction was determined from the change in the BH characteristics when stress was applied to the film. This result is also 1-A
Shown in the table.

On the other hand, Table 1-B shows three types of heat treatments obtained on crystallized glass substrates in the same manner as in the manufacturing method of the soft magnetic thin film of Example 1 except that nitrogen was not contained in the atmosphere during sputtering. Thin film (No. 1 of Comparative Example 1.

The measurement results of the composition, saturation magnetic flux density Bs, and coercive force ■C of 2.3) are shown below.

In addition, FIG. 2 shows the relationship between the composition and coercive force Hc of the soft magnetic thin film manufactured by the soft magnetic thin film manufacturing method of Example 1, and the positive/negative determination of magnetostriction (when heat treated at 550° C. using a crystallized glass substrate). Shown below. Furthermore, the relationship between the soft magnetic thin film production conditions of Fe content in the Fe-Zr alloy target and N2 content in the sputtering gas, coercive force He, and saturation magnetostriction λ (using a crystallized glass substrate with 550 3) is shown in FIG.

X-ray diffraction and electrical resistivity Fe 110.11 Z r in Example 1 above 6.
5 The composition of N12.6 was unheated (as dep
o) thin film of 250°850, 450 or 55
The results of X-ray diffraction for the thin film heat-treated at 0°C are shown in the fourth section.
The results of measuring the electrical resistivity shown in the figure are shown in Table 2. According to FIG. 4, it was found that the crystal grain size of the thin film heat-treated at 550° C. was about 130 grains based on the half-width. In addition, as d
The epo thin film and the thin film heat-treated at 250°C are amorphous, and the thin films heat-treated at 850°C and 450°C are composed of microcrystals.

It was found that the thin film heat-treated at 550° C. consisted of further grown microcrystals. These microcrystals are thought to contribute to the soft magnetic properties of the thin film, and the generation of such microcrystals is due to the presence of N and Zr.
This is thought to be due to the existence of According to Table 2, the resistivity of this thin film decreases by increasing the heat treatment temperature.

Even when heat treated at temperatures up to 550℃.

Its value is much higher than that of pure iron, permalloy, etc.
The value is almost the same as that of e-8i alloy and Sendust. Therefore, when used as a core of a magnetic head, the eddy current loss is small and advantageous.

Vickers hardness further F e 8G, 9 Z r 6.11 N12.
As a result of measuring the Vickers hardness of the thin film having the composition No. 6, a value of Hv-1000 (kg/ad, weight 10 g) was obtained. This value is based on sendust and Co-based amorphous alloys (Hv-
500 to 650), and the abrasion resistance can be sufficiently improved compared to conventional ones.

BH Convex Curves The BH convex curves of several thin film AC BH) racers produced in the same manner as in Example 1 are shown in FIG.

The sample shown in Fig. 5 was placed in a magnetic field of 1 kOe after film formation.
550℃, 60℃ in 10Torr N2 atmosphere
Heat treated for minutes. As is clear from this figure, clear in-plane-axial anisotropy is induced in the thin film by the magnetic 5 6 field heat treatment. Therefore, by setting the difficult axis direction of this thin film as the magnetization direction, the magnetic permeability at frequencies higher than I MHz can be made sufficiently high, and from this point as well, it is advantageous as a magnetic head material. Also, since this anisotropic magnetic field Hk varies from 3 to 180e depending on the composition,
The material can be selected depending on the desired magnetic permeability and the frequency range used. For example, if you want to obtain high magnetic permeability below 10 MHz, use Hk-3 to 50e.
In order to prevent the magnetic permeability from deteriorating even at higher frequencies, a composition with a higher Hk can be used.

MH convex curve Line 6 shows FeB in Example 1. ,.

The results of MH convex curves measured using VSM for thin films with compositions of Zr6,3N1°,6 are shown.

In the figure, (a) shows the thin film immediately after film formation (as depo).

(b) is the M of the thin film after heat treatment in a magnetic field at 550°C.
The H convex curve is shown. (Demagnetizing field correction was not performed.

However, the sample shape was φ5 mm x tO1B3-. ) The coercive force measured using the VSM is more than an order of magnitude smaller than the value determined using the AC BH tracer, and was determined to be about 50 m0e from (b). This value is almost the same as that of Sendust and Co-based amorphous alloys, and it can be seen that the soft magnetic properties are excellent.

Further, from (b), 4πM s -14.5 KG is found, which is sufficiently higher than Sendust or Co-based amorphous alloys, and is advantageous as a magnetic head material for recording on high coercive force media.

The 4πMs of the thin film before heat treatment is 13.0 KG, which is slightly lower than that after heat treatment. In addition, vertical anisotropy (Hk=4000e
), Hc is high, and soft magnetic properties are poor.

Corrosion resistance Fe Bo, 9 Z r 6.5 in Example 1 above
The corrosion resistance of the thin film having a composition of N 12.6 was evaluated based on the change in surface condition after being immersed in tap water for about one week. As a result, the surface condition of the nine samples remained mirror-like and did not change at all. For comparison, C088,47 8 N b 8. . Zr3,6 amorphous alloy film and Fe
A similar experiment was conducted for -5i alloy (electromagnetic steel sheet). As a result, the Co--Nb--Zr alloy did not change at all, but the Fe-8i alloy developed rust all over. From the above, it was found that the soft magnetic thin film used as the soft magnetic layer of the magnetic head of the present invention also has excellent corrosion resistance.

Next, two soft magnetic thin films having compositions outside the composition range of the soft magnetic layer of the magnetic head of the present invention will be described.

(Comparative Example 2) An amorphous alloy film of F e 91.2 Z r 3i N 4.9 was formed and heated at 350° C. and 550° C. in a magnetic field of 1 kQe.
Heat treatment was performed at ℃ for 1 hour. The amorphous alloy film (as
depo).

BH curves measured by an AC BH tracer for a film heat-treated at 350°C and a film heat-treated at 550°C are shown in FIGS. 7(a) to (C), respectively. The immaturely processed amorphous alloy film (as depo) does not have soft magnetism (a).

The film heat-treated at 850°C exhibits -axis anisotropy (
b). However, the properties of the film heat-treated at 550° C. deteriorated (C).

When manufacturing magnetic heads, welding (glass bonding) using molten glass is sometimes performed2, and is usually performed by heating to about 550.degree. In the case of using a film having a composition in the range described in 2 above, the final magnetic head will not exhibit good soft magnetism due to the heating during glass bonding. That is, in the case of the above composition range, only a thermally unstable soft magnetic thin film can be obtained.

(The following are blank spaces) 9 0 Table A Table 1 Table B Table 2 (Example 2) Using an alloy target with a composition of F e 92.5 Z r 7.5, 2.5. 5.0. 7.5.10.
Two Fe-Zr-N amorphous thin films with various compositions were deposited on sapphire substrates (
R surface).

The amorphous thin film formed on the substrate was heated to 350°C or 550°C.
A Fe--Zr--N soft magnetic thin film was obtained by heat treatment at .degree. C. for 1 hour. Table 3 shows the composition, saturation magnetic flux density Bs, and coercive force Hc of the obtained Fe-Zr-N soft magnetic thin film.

(Comparative Example 3) Table 3 also shows the composition, saturation magnetic flux density Bs, and coercive force Hc of a heat-treated thin film obtained in the same manner as in Example 2 except that nitrogen was not contained in the atmosphere during sputtering.

(The following is a blank space) Table 3 (Example 3) A target with a composition of F e so Z r +o (at%) was used, and a gas pressure of 0.5% was used in a nitrogen-containing argon gas atmosphere containing 6.0 mol% nitrogen. High frequency sputtering was performed under the conditions of 8 Pa and input power of 400 W to deposit Fe on the sapphire substrate (R side, flTO21 side).
A 75.9 Z r 7.3 N+8.8 amorphous thin film was formed.

The amorphous thin film formed on the substrate was heated to 250°C.

60 minutes at 850°C, 450°C, 500°C or 550°C.

3 4 120 minutes, 180 minutes, 240 minutes, 540 minutes,
A soft magnetic thin film was obtained by heat treatment in an isothermal magnetic field (1.1 kOe applied in <0010> direction) for 1140 minutes, 2400 minutes, or 4800 minutes. The obtained Fe-Zr-
BH characteristics of N soft magnetic thin film (measured magnetic field Hm = 25 (
0e)), coercive force Hc, and anisotropic magnetic field Hk are shown in FIG.

The 14th picture shows (a) coercive force Hc and (
b) The relationship between the anisotropic magnetic field Hk is shown. Also.

FIG. 15 shows (a) the relationship between heat treatment time t [min], heat treatment temperature, and coercive force Hc, and (b) heat treatment time t
The relationship between [min], heat treatment temperature, and anisotropic magnetic field Hk is shown.

From these, the change in BH characteristics due to heat treatment temperature is 35
A range of 0 to 500°C, a range of over 500°C, and 3
It can be seen that there are differences in the three temperature ranges below 50°C.

In addition, the above F e 75.9 Z r 7.3 NII
+, 8 amorphous thin film at 250°C for 4800 minutes, 350
Compositions (at%) of five types of soft magnetic thin films obtained by heat treatment at ℃ for 240 minutes, 450℃ for 180 minutes, 500℃ for 180 minutes, or 5509C for 1140 minutes, Zr content (at%) of the soft magnetic thin films %) and Fe content (at%)
The ratio Z r /F e .

Ratio of N content (at%) to Zr content (at%) N/
Table 4 shows Zr and BH characteristics (measured magnetic field Hm=25 (Oe)). Each composition below is +F es+, 2(Z
r・NX) 8.11 However, it can be expressed as x-N/Zr.

According to Table 4, the value of N/Zr is determined at a heat treatment temperature of 250°C.
It is almost constant within the range of 350°C to 500°C, and the heat treatment temperature is around 300°C and around 500°C.
It can be estimated that there is a heat treatment temperature near C where the value of N/Zr suddenly changes.

Table 4 5 6 X-ray diffraction pattern Fe-Zr-N soft magnetic thin film obtained in Example 3,
F e 75.9 Z r 7.3 N+6 before heat treatment
．． 8 X-ray diffraction pattern of amorphous thin film (as depo) (ray source CuKa ray 40kV, 30+nA, λ-1
, 5,405 people) are shown in Figure 16. This X-ray diffraction pattern will be described below.

In the case of the as-depo thin film, it shows a typical halo pattern, confirming that it is amorphous.

The position of the main peak shifts to the wide-angle side as the heat treatment temperature increases, and finally becomes 2θ-44,8' after heat treatment at 550°C, coinciding with the αF e (110) peak. 2
At 50℃ x 4800 minutes, it becomes 2θ-43.7°.

This coincides with the F e3 Z r (440) peak.

In heat treatment from 350℃ to 500℃, 2θ''i 44'
, which is a F e (110) and F e3 Z
This corresponds to a value approximately in the middle of the r(440) peak.

The grain size, calculated from the half width of the main peak using the 5eherrer formula, is approximately 100 at 250°C to 450°C, approximately 120 at 2500°C x 180 minutes, and 120 at 550°C x 1.
Approximately 170 people in 140 minutes (approximately 13 people at 550℃ x 60 minutes)
0 people (see Example 1 and FIG. 4)) and temperature x time.

The relationship between the heat treatment time at 550°C, the position of the main peak, and the grain size is as follows.

From this, heat treatment at 550°C shows that fine α is formed relatively quickly.
Although the Fe phase precipitates, it can be seen that crystal grains grow slightly over the course of 9 hours.

In addition, in the heat treatment at 550°C, Fe3 was newly added in addition to αFe.
Peaks thought to be Zr and ZrN were observed, and it is thought that these were finely precipitated.

(Example 4) For a target rattler with a composition of F e no Z r 10 (at%) 7 8 , in a nitrogen-containing argon gas atmosphere containing 5.0 mol% nitrogen, the gas pressure was 0.6 Pa, and the input power was 200 W. High frequency sputtering was performed under the following conditions.

An Fe-Zr-N amorphous thin film was formed on a sapphire substrate (R side).

Amorphous thin film (thickness approximately 0.6 μm) formed on the substrate
The temperature change in magnetization (normalized to magnetization at room temperature) was measured by VSM. The results are shown in FIG. Measurements were performed starting at room temperature and increasing the temperature at approximately 3'C/min. Sample B was heated to 340°C for 120 minutes, the sample was heated to 450°C for 60 minutes, and sample E was heated to 500°C for 60 minutes.
Sample G was held at 520°C for 180 minutes, and sample F was held at 550°C for 120 minutes. After that, -3℃/min
Measurements were taken while the temperature was lowered to room temperature. From FIG. 17, the Curie temperature of the Fe-Zr-N amorphous thin film (as depo) before heat treatment is about 250°C, and at least 340°C.
It can be seen that when the temperature is maintained above ℃, the magnetization value increases and the Curie temperature increases. When held at 550℃ for 120 minutes.

Curie temperature is over 700℃, and heat treatment increases α
It can be seen that the temperature approaches the Curie temperature of Fe (770°C). The magnetization at room temperature is in each case aS dep
The temperature is higher than that of the as-depo amorphous thin film, but it is almost saturated when held at 520-550°C, and the as-depo amorphous thin film is 1.12~
It is 1.14 times higher.

What was learned from Examples 3 and 4 will be described for each heat treatment temperature.

(a) Before heat treatment (as depo) Structurally, it is amorphous. Soft magnetism has not been obtained,
The Curie temperature is considerably lower than that of αFe, and the magnetic moment is lower than that after heat treatment. These are possible characteristics for an Fe-based amorphous alloy. In addition, the N content is 16
．． As many as 8%.

N/Zr=2.8.

(b) 250°C heat treatment The BH characteristics were slightly improved compared to as depo, with Hc of 5 to 70e. By increasing the heat treatment time, crystallization was confirmed by X-rays after 4800 minutes.

In addition, a -axis anisotropic film (Hc = 1.40e) was obtained.

The position of the main peak is F e3 Z r (440)
90 corresponds to the peak. The N content after heat treatment is as depo
There is no difference.

(C) 350-500°C heat treatment main peaks are F e3 Z r (400) and a
Located in the middle of the F e (110) peak, Z
A broad bulge is also seen near r N (200), indicating a complicated state. In terms of BH characteristics, Hc = 0.7 to 0.90e, Hk -9
Heat treatment time x temperature increases at ~120e
tends to become larger. Although the Curie temperature changes continuously within this range, the magnetization at room temperature is 1.
It is approximately constant at 0.6 to 1.08 times. The N content after heat treatment is slightly lower at 500°C than before heat treatment, but N/
This is the region of Zrz2.

(d) 550°C heat treatment The main peak clearly corresponds to the αF e (110) peak, and new peaks that appear to be Fe3Zr and ZrN also appear. From this, after heat treatment at 550"C, fine crystals of (110) oriented αFe (grain size 1
00 to 200) and even finer Fe3Zr, Zr
It is thought that N etc. are precipitated. However, the Curie temperature is lower than the Curie temperature of αFe, 770°C, and this is thought to be related to the fact that the crystal grains are fine.

He decreased due to long-term heat treatment and reached a minimum level in about 400 minutes.
After that, it increases slightly again. Hk decreases with time and becomes almost isotropic in about 250 minutes.

The N content after heat treatment depends on the heat treatment time, and it decreases from N/Z r z 1.8 after 60 minutes of heat treatment to 1.1 after 1140 minutes of heat treatment. It is considered that some nitrogen is released from the sample as N2 gas due to the 550° C. heat treatment.

As described above, when an Fe-Zr-N amorphous thin film is heat-treated, the structure and properties of the resulting soft magnetic thin film vary depending on the heat treatment temperature. This also corresponds to Table 2 showing the electrical resistivity of Example 1.

The above contents are schematically shown in FIG.

(Example 5) Feg. An alloy target with a composition of Zr1° was used.

By performing high frequency sputtering in a nitrogen-containing argon gas atmosphere containing 6.0 mol% nitrogen, + Fe VL22 r 7.3 N 16.5 and Fe75.9Z r ? , a N16 and amorphous thin films with two compositions of 8 were formed on sapphire substrates (R-plane), respectively. However, the former uses a φ6 inch target and the total pressure is 0.
Sputtering was performed at a total pressure of 0.8 Pa and an input power of 400 W using a 4-inch target.

F e 76.2 Z r 7. formed on the substrate.
3 N16.5 amorphous thin film was heat-treated at 550°C for 60 minutes in a magnetic field to obtain +Fe7? , a Z r 7.8 N1
A 3.6 soft magnetic thin film (film thickness approximately 1 μm) was obtained. Further, F e 75.9 Z r 7. formed on the substrate. l'
N16. B The amorphous thin film was heat-treated at 550°C in a magnetic field,
A soft magnetic thin film was obtained. The composition of the soft magnetic thin film is F e 79.2 Z r 7.5 when the heat treatment time is 60 minutes.
N13.3, and in the case of 1140 minutes, F e
B3.2 Z r 8. ONB was 8. The composition and saturation magnetic flux density Bs of these soft magnetic thin films obtained.

The coercive force Hc and anisotropic magnetic field Hk are shown in Table 5.

2 Table 5 (Example 6) Fe+x−y Hfy (Y −5,0,10,0
, 15,0 (at%)) by performing high-frequency snok tuttering in a nitrogen-containing argon gas atmosphere containing 2,4,6°8.10 or 12 mol% nitrogen. Fe-Hf-N amorphous thin films of various compositions were formed on a sapphire substrate (R-plane).

The amorphous thin film formed on the substrate was heated to 350°C or 55°C.
Heat treated in a magnetic field of 1.1 kOe at 0°C for 1 hour.

A Fe-Hf-N soft magnetic thin film (film thickness: 1μ11) was obtained.

Composition 73 of the obtained Fe-If-N soft magnetic thin film 4 Table 6 shows the saturation magnetic flux density Bs and coercive force Hc.

(Comparative Example 4) Table 6 also shows the composition, saturation magnetic flux density Bs, and coercive force Hc of three types of heat-treated thin films obtained in the same manner as in Example 6 except that nitrogen was not contained in the atmosphere during sputtering.

(Left below) 5 (Example 7) F e+oo-y Tay (y -5,0,10
, 0, 15, 0 (at%)) by performing high frequency sputtering in a nitrogen-containing argon gas atmosphere containing 2, 4, 6 mol %, 10 or 12 mol % nitrogen. Fe-Ta- with a composition of N
An N amorphous thin film was formed on a sapphire substrate (R side).

The amorphous thin film formed on the substrate was heated to 350°C or 550°C.
℃, heat treated in a magnetic field of 1.1 kOe for 1 hour.

A Fe-Ta-N soft magnetic thin film (1 μm in film thickness) was obtained. Composition of the obtained Fe-Ta-N soft magnetic thin film.

Table 7 shows the saturation magnetic flux density Bs and coercive force Hc.

(Comparative example 5) Other than not containing nitrogen in the atmosphere during sputtering.

Table 7 also shows the composition, saturation magnetic flux density Bs, and coercive force Hc of the heat-treated thin film obtained in the same manner as in Example 7.

(Left below) 7 (Example 8) F e+on-y N by (y -5,0,10
, 0, 15, 0(ate)) and two different compositions by performing high-frequency sputtering in a nitrogen-containing argon gas atmosphere containing 2, 4, 6.8, or 10 mol% nitrogen. An Fe--Nb--N amorphous thin film was formed on a sapphire substrate (R surface).

The amorphous thin film formed on the substrate was heated to 350"C or 5"C.
Heat treated at 50°C in a 1.1 kOe magnetic field for 1 hour.

A Fe7Nb-N soft magnetic thin film (film thickness: 1μ11) was obtained.

Composition of the obtained Fe-Nb-N soft magnetic thin film.

Table 8 shows the saturation magnetic flux density Bs and coercive force He.

(Comparative Example 6) Table 8 also shows the composition, saturation magnetic flux density Bs, and coercive force Ha of a heat-treated thin film obtained in the same manner as in Example 8 except that nitrogen was not contained in the atmosphere during sputtering.

(Leaving space below) Table 8 (Example 9) High frequency sputtering was performed in a nitrogen-containing argon gas atmosphere containing 6.0 mol% nitrogen using a target with a composition of 'F e 90 Z r la (ate). By doing this, an Fe-Zr-N amorphous thin film was formed on the substrate. As the substrate, a 5i02 film-coated ferrite substrate, which is obtained by forming a 5i02 film on a ferrite substrate, was used.

The amorphous thin film was formed on the surface of the 5i02 film.

The amorphous thin film formed on the substrate was heated to 550°C.

Heat treated in a magnetic field (magnetic field strength, LkOe) for 1 hour,
- A soft magnetic thin film (thickness: 5.9p) having axial magnetic anisotropy was obtained. What is the composition of the soft magnetic thin film obtained?

From the composition of a soft magnetic thin film obtained under the same conditions except that a sapphire substrate was used instead of the above substrate.

The electrical resistivity ρ of the obtained soft magnetic thin film was estimated to be F e 7'1.8 Z r 7.6 N14.6 and was 77 cm, and the Vickers hardness Hv was 1010 kg/-. Further, the frequency characteristics of magnetic permeability of the obtained soft magnetic thin film are shown in Fig. 19-A, and the B-H curve is shown in Fig. 19-B.

(Example 10) By performing high frequency sputtering in a nitrogen-containing argon gas atmosphere containing 4.0 mol% nitrogen using a target with a composition of Fe-Hf-N amorphous A thin film was formed on the substrate. As the substrate, a 5i02 film-coated ferrite substrate, which is formed by forming an Si02 film on a ferrite substrate, was used. The amorphous thin film was formed on the surface of the 5i02 film.

The thickness of the amorphous thin film formed on the substrate was 4.7 μm. This was heat treated at 550° C. in a magnetic field of 1.1 koel for 1 hour to obtain a soft magnetic thin film. and.

After measuring the magnetic permeability and anisotropic magnetic field Hk of this thin film, an additional heat treatment was performed for 2 hours under the same conditions as above except for another 2 hours (total heat treatment for 3 hours). Here, the magnetic permeability and anisotropic magnetic field were also measured, and an additional heat treatment was performed for 3 hours (total heat treatment for 6 hours) under the same conditions as above except for the time.

Magnetic permeability and anisotropy field Hk were measured. The compositions of two of the three soft magnetic thin films obtained were based on the compositions of soft magnetic thin films obtained under the same conditions except that a sapphire substrate was used instead of the above substrate and the film thickness was 1 μm. , each r
Fe 77.4 Hf 7.5 N15.1 (
1 hour heat treatment), and F eo, e Hf 7.7 N
It was estimated to be 9.7 (6 hours heat treatment).

The electrical resistivity ρ of the obtained soft magnetic thin film (heat treated for 6 hours) is 60I! Q-cm, Vickers hardness Hv is 110
It was 0 kg/-. The frequency characteristics of magnetic permeability of this soft magnetic thin film (heat treated for 6 hours) are shown in Figure 20-A, and B-H
The curve is shown in Figure 20-B.

Also, the magnetic permeability (at I MHz) of the three heat treatment stages
The μIM Hz and anisotropic magnetic field Hk are shown in FIG. 20-0. FIG. 20-0 shows changes in the magnetic permeability μm□2 and the anisotropic magnetic field Hk with respect to the heat treatment time of the Fe-Hf-N thin film.

(Example 11) Fe-Ta- An N amorphous thin film was formed on the substrate. As the substrate, a 5i02 film-coated ferrite substrate, which is obtained by forming a 5i02 film on a ferrite substrate, was used. The amorphous thin film was formed on the surface of the 5i02 film.

The amorphous thin film formed on the substrate was heated to 550°C.

Heat treated in a magnetic field (magnetic field strength 1.1 koe) for 1 hour,
- Soft magnetic thin film with axial magnetic anisotropy (film thickness 5.6/7J
I) was obtained. What is the composition of the soft magnetic thin film obtained?

From the composition of a soft magnetic thin film obtained under the same conditions except that a sapphire substrate was used instead of the above substrate.

F e 611.8 T a 11.5 N 18.7
estimated that.

The electrical resistivity ρ of the obtained soft magnetic thin film was 86 tlQ-cm
The Vickers hardness Hv was 1220 kg/-. Further, the frequency characteristics of magnetic permeability of the obtained soft magnetic thin film are shown in Fig. 21-A, and the B-H curve is shown in Fig. 21-B.

Embodiments of the magnetic head of the present invention will be described below with reference to FIGS. 8 to 10 of the two drawings.

(Example 12) 3 4 FIG. 8 is an enlarged perspective view of the tip of the composite magnetic head of the present invention, and FIG. 9 is an enlarged view of the composite magnetic head in FIG. Figure).

The ferrite core 1 has tip opposing surfaces 1a and la' and a recess 1b that is formed to be set back from the opposing surfaces.

1b', and are joined at a predetermined position (not shown) to form an integral body. Ferrite core tip facing surfaces la, la'
and recesses 1b, lb' formed retreating from the opposing surface.
1 is sequentially provided with soft magnetic layers 2, 2' and 5i02 layers 3, 3' specified in the present invention. Soft magnetic layer 2.2
' forms part of the core of the magnetic head. The soft magnetic layer portions existing between the tip facing surfaces 1a and 1a/ of the ferrite core 1 are opposed to each other, and a gap is formed between the soft magnetic layer facing surfaces. The 5i02 layer portion provided in the recess or edge portion of the ferrite core via the soft magnetic layer is coupled to the glass filling portions 5, 5'.

Three types of secondary magnetic layers were used as the soft magnetic layer.

(1) Composition is F e 110.9 Z r 6.5 N
12.8, and the composition of the soft magnetic layer (2) having -axis magnetic anisotropy is Fe 82.8 Hf 7. 'I N
9.7, and the composition of the soft magnetic layer (3) having -axis magnetic anisotropy is Fe BG, 8 Ta 11.15
An example of a method for manufacturing the composite magnetic head shown in FIGS. 8 and 9 will be outlined below.

A soft magnetic layer 2 is formed on the front end facing surface 1a of the ferrite core half body and the recess 1b formed at a position set back from the facing surface using, for example, the above-mentioned example of manufacturing a soft magnetic thin film or a method similar thereto. A SiO□ layer is formed on the soft magnetic layer by a predetermined method. In this way.

A multilayer core half is obtained by forming the two types of layers on a ferrite core half. Along with this multilayer core half, another multilayer core half that constitutes the head is obtained by a similar manufacturing method.

The pair of multilayered core halves obtained as described above are butted in a predetermined direction, and the recesses of the core halves are filled with melted glass and cooled to join the pair of core halves together, as shown in Figure 2. Manufacture a composite magnetic head.

(Embodiment 13) FIG. 10 is a schematic enlarged sectional view of a thin film magnetic head of the present invention in the gap depth direction (perpendicular to the recording medium orientation plane), and the following description will be made based on this figure.

The ferrite substrate 10 has a lower soft magnetic layer 11. Insulating layer 12
, a coil conductor layer 18 and an upper soft magnetic layer 15 in this order. Between the lower soft magnetic layer 11 and the upper soft magnetic layer 15,
Magnetic gap layer 1 reaching the recording medium directional surface 20 of the head
There are 4. On the other surface of the upper soft magnetic layer 15,
A protective layer 1B is provided to protect the soft magnetic layer. The protective layer 16 is bonded to the protective plate 19 by a bonding glass layer 18 .

The lower soft magnetic layer 11 and the upper soft magnetic layer 15 are 1
The following three types were used.

(1) Composition is F e go, 9 Z r 8.6 N1
2.6, and the composition of the soft magnetic layer (2) having -axis magnetic anisotropy is Fe a2.6 Hf 7.7 N 9
．． 7 and - Soft magnetic layer (3) having axial magnetic anisotropy composition is Fe 6G, 8 T 8114 N 1
11.7 - Soft magnetic layer having axial magnetic anisotropy An example of a method for manufacturing the thin film magnetic head shown in FIG. 10 will be outlined below.

A lower soft magnetic layer 11 with a thickness of 10 − is formed on a ferrite substrate IO.
form. The lower soft magnetic layer 11 is formed by, for example, the method for manufacturing soft magnetic thin films described above or a method similar thereto. Next, a nonmagnetic insulating layer 12 made of 5i02 or the like and Cu are placed at predetermined positions on the lower soft magnetic layer 11.

After suitably forming the coil conductor layer 13 made of 8 (or the like), the cross section of the non-magnetic insulating layer 12 including the coil conductor layer 13 is processed into a substantially trapezoidal shape by ion milling as shown in the figure.Next, the gap layer 14 is The gap layer 14 is removed from a predetermined position (not shown) where it will be directly connected to the upper soft magnetic layer 15 to be formed later, and the gap layer 14 is removed from a predetermined position (not shown) by the same method as the lower soft magnetic layer 11. ) to form an upper soft magnetic layer 15 with a thickness of 10 μl bonded to the lower soft magnetic layer 11.

7 8 Next, a protective layer 16 is formed on the upper soft magnetic layer 15.

After the protective layer 16 is formed, the protective layer 16 is flattened and bonded to a protective plate 19 via a bonding glass layer (Si02-PbO-B20. based glass) 18 to smooth the recording medium orientation surface 20. A thin film magnetic head, which is an embodiment of the present invention, was fabricated.

(Embodiment 14) FIG. 11 is an enlarged perspective view of the tip of a composite magnetic head which is an embodiment of the present invention. FIG. 12 is a schematic enlarged view of the recording medium orientation plane (view A) of the composite magnetic head.

The magnetic head core 33 is made up of alternately laminated soft magnetic layers 31 and insulating layers 32 such as 5i02, and has a tip facing surface 33a,
33a' and a recess 33 formed retreating from the opposing surface.
b, 33b'. On the opposing surface.

The end face of the soft magnetic layer is exposed. That is, most of the opposing surface is constituted by the end surface of the soft magnetic layer.

A gap layer G made of SiO□ is formed between the opposing surfaces. The side surface of the magnetic head core 88.

It is coupled with non-magnetic substrates 84-87. Filled glass part 8
8 is filled between the nonmagnetic substrates 34 and 36 to increase the bonding strength of the entire magnetic head.

The magnetic head of the present invention has a soft magnetic layer with higher hardness than conventional magnetic heads.

Even in composite magnetic heads such as those mentioned above.

The recording medium orientation surface has even higher abrasion resistance (higher durability).

Three types of primary soft magnetic layers were used.

(1) Composition is F e 80.9 Z r 6.5 N1
2.6, and the composition of the soft magnetic layer (2) having -axis magnetic anisotropy is Fe 82.8 Hf 7.7 N 9
．． 7, and the composition of the soft magnetic layer (8) having -axis magnetic anisotropy is Fe 6f1. ll Ta 11.5
N 18.7 and a soft magnetic layer having -axis magnetic anisotropy [Effects of the Invention] As is clear from the above explanation, the soft magnetic layer of the magnetic head of the present invention is made of sendust alloy or amorphous soft magnetic material. It has a saturation magnetic flux density of 90 degrees, which is much higher than that of alloys, can have zero magnetostriction, and has excellent soft magnetic properties such as low coercive force and high magnetic permeability.

In addition, the soft magnetic layer has a high electrical resistivity comparable to Sendust and can have uniaxial anisotropy, and its size can be controlled by the composition and heat treatment time, so it is possible to obtain high frequency permeability according to the purpose. I can do it. Another 650'
Since the characteristics do not deteriorate even after heat treatment up to C,
It has excellent heat resistance for glass bonding, etc., and also has high hardness and corrosion resistance, so it has high wear resistance and high reliability.

The soft magnetic layer in the magnetic head of the present invention can be formed by heat-treating an amorphous alloy film to make it microcrystalline. Therefore, when forming two layers, step coverage is good and a mirror surface can be easily obtained, and multilayer films can be formed. Since coarsening of crystal grains can be prevented without relying on the above method, it is possible to increase the thickness of the film.

Therefore, the magnetic head of the present invention can be used with magnetic recording media of high coercive force, and can achieve higher quality, wider bandwidth, and higher recording density.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the composition range of the soft magnetic layer in the magnetic head of the present invention. FIG. 2 is a diagram showing the relationship between the composition of the soft magnetic thin film manufactured in Example 1 and the coercive force Hc, and the determination of whether the magnetostriction is positive or negative. FIG. 3 is a diagram showing the relationship between the soft magnetic thin film manufacturing conditions and the coercive force He and saturation magnetostriction λ of the soft magnetic thin film manufactured thereby. FIG. 4 is a diagram showing the results of X-ray diffraction measurements of thin films subjected to different heat treatment conditions. FIG. 5 is a diagram showing AC BH convex curves of thin films with two different compositions. FIG. 6 is a diagram showing IH curves of the thin film before and after heat treatment determined by VSM. FIG. 7 is a diagram showing an AC BH convex curve of a soft magnetic thin film having a composition outside the composition range of the soft magnetic layer of the magnetic head of the present invention. FIG. 8 is a schematic enlarged perspective view of the tip of an embodiment of the composite magnetic head of the present invention. Figure 9 shows the 8th
FIG. 2 is a schematic enlarged view of an embodiment of the composite magnetic head shown in FIG. FIG. 10 is a schematic enlarged sectional view in the gap depth direction of an embodiment of the thin film magnetic head of the present invention. FIG. 11 is an enlarged perspective view of the tip of an embodiment of the composite magnetic head of the present invention. FIG. 12 is a schematic enlarged view of the composite magnetic head shown in FIG. 11 in the direction of arrow A. FIG. 13 is a diagram showing the BH characteristics, coercive force Ha, and anisotropic magnetic field Hk of a Fe-Zr-N soft magnetic thin film. FIG. 14 is a diagram showing the relationship between the coercive force Hc and the anisotropic magnetic field Hk of the Fe-Zr-N soft magnetic thin film obtained with respect to the heat treatment time t. FIG. 15 shows the relationship between heat treatment time t, heat treatment temperature, and coercive force Hc. and FIG. 7 is a diagram showing the relationship between heat treatment time t, heat treatment temperature, and anisotropic magnetic field Hk, respectively. FIG. 16 is a diagram showing the X-ray diffraction patterns of a Fe-Zr-N soft magnetic thin film and an amorphous thin film before heat treatment. Figure 17 is. FIG. 3 is a diagram showing temperature changes in magnetization of a Fe-Zr-N soft magnetic thin film. FIG. 18 is a diagram showing estimation of the characteristics of a soft magnetic thin film obtained by heat treatment time t and heat treatment temperature. 1st
FIG. 9-A, FIG. 20-A, and FIG. 21-A are diagrams showing frequency characteristics of magnetic permeability of two soft magnetic thin films according to an embodiment of the present invention. Figure 2 19-B, Figure 20-B and Figure 21-B are respectively. FIG. 3 is a diagram showing AC BH convex curves in the easy axis direction (upper stage) and the hard axis direction (lower stage) of a soft magnetic thin film according to an embodiment of the present invention;
B is an arbitrary unit. Figure 20-C shows Fe-Hf-
FIG. 3 is a diagram showing changes in magnetic permeability μm□2 and anisotropic magnetic field Hk of a Fe-Hf-N soft magnetic thin film with respect to heat treatment time of an N amorphous thin film.

Claims (1)

Scope of Claims: (1) A magnetic head core having a tip facing surface and a recess formed recessed from the facing surface, a soft magnetic layer exposed at least on the facing surface, and between the facing surfaces of the core. The soft magnetic layer comprises a gap, and the soft magnetic layer is Fe_aB_bN_c.
(However, a, b, and c each indicate atomic %, and B is Zr, H
f, Ti, Nb, Ta, V, Mo, and W. ), and the composition range is 0<b≦20 and 0<c≦22 (excluding b≦7.5 and c≦5). (2) A lower soft magnetic layer, an insulating layer, a coil conductor layer, and an upper soft magnetic layer are sequentially provided on the substrate, and a magnetic gap layer that reaches the recording medium orientation plane of the head between the lower soft magnetic layer and the upper soft magnetic layer. The soft magnetic layer comprises Fe_aB_bN_c (where a, b,
c each represents atomic %, B represents Zr, Hf, Ti, Nb,
Represents at least one of Ta, V, Mo, and W. )
1. A thin film magnetic head having a compositional formula of 0<b≦20 and 0<c≦22 (excluding b≦7.5 and c≦5). (3) The magnetic head according to claim 1 or 2, wherein the composition range is 69≦a≦93, 2≦b≦15, and 5.5<c≦22. (4) The composition range is defined by the ternary composition coordinate system (
P (91, 2, 7) Q (92.5, 2, 5.5) R (87, 7.5, 5.5) S (73, 12, 15) T (69 , 12, 19) U(69, 9, 22) V(76, 5, 19). (5) The magnetic head according to any one of claims 1 to 4, wherein the soft magnetic layer has uniaxial anisotropy. (6) The magnetic head according to claim 1, wherein the soft magnetic layer has a crystal grain size of 300 Å or less.