JPS5998318A - Magnetic reproducing thin film head - Google Patents

Abstract

PURPOSE:To improve the reproduction sensitivity by forming magnetic shielding thin films of a ternary amorphous Co alloy contg. Zr and Ta or a quaternary amorphous Co alloy contg. Zr, Ta and Nb on both sides of a magneto-resistance element. CONSTITUTION:The 1st magnetic shielding film 3, a magneto-resistance (MR) element 4, electrically conductive thin films 5, 6, and the 2nd magnetic shielding film 7 are successively laminated on an insulating film 2 on a nonmagnetic substrate 1 to obtain a magnetic head. The films 3, 7 are thin films of an amorphous Co alloy contg. about 5-20wt% in total of >= about 2.5wt% Zr and Ta or about 5-20wt% in total of >= about 2.5wt% Zr, Ta and Nb and having high magnetic permeability and high saturation magnetic flux density. The films 3, 7 are formed by sputtering or vapor deposition, and it is preferable to reduce the anisotropic magnetic field by carrying out heat treatment in a rotating magnetic field. Thus, the reproduction efficiency is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thin film magnetic head, and more particularly to the material of an air shield in a reproducing head thereof.

The carbon dioxide magnetic reproducing head includes a substrate made of a non-magnetic phase, a first magnetic shield thin film, a magnetoresistive element (hereinafter abbreviated as MR element), and a second magnetic shield thin film, which are sequentially provided on the substrate. It is composed of etc. This thin 11-magnetic 1 reproducing head is paired with a thin film H-head to form a thin film head.

In order to fully exhibit its function as a magnetic shielding thin film F film of this thin film magnetic reproducing head, it is required that both magnetic permeability and saturation magnetic flux density are high. Conventionally, as this magnetic shielding thin film, a binary permalloy made of an iron-niranal alloy, or a multi-component permalloy in which a third element such as chromium, molybdenum, or copper is added to the binary permalloy has been used. However, with permalloy, it is generally difficult to make the magnetic permeability and saturation magnetic flux density sufficiently high, and a sufficient shielding effect cannot be obtained.

As a result of various studies on amorphous alloy thin films obtained by sputtering etc., the present inventors found that the main component is cobal (Co) and a small amount of zirconium (Zr).
) and Co-zr-TcL added with tantalum (TcL)
ternary amorphous alloys, as well as cobal (Co)
), with small amounts of zirconium (Zr), tantalum (Ta), and niobium (Nb) added.
It has been found that four-component amorphous alloys of -TG-Nb have excellent properties as shielding materials for thin-film magnetic reproducing heads.

For the first time, the Co-Zr-'I'a-based amorphous alloy will be explained.

Using crystallized glass as the substrate, a cobalt disk (diameter 4
zirconium pellets and tantalum pellets (thickness: 1 inch, 5 inches thick) on top of zirconium pellets and tantalum pellets.
The alloy composition can be changed by arranging the number of pellets on the target J to 11 (thickness 1) in a radial direction from the center. In a high vacuum of less than lXl0 TOrr, in an argon atmosphere, high frequency?! 1. Force 2. OW
/cn? Sputtering is performed to form a three-component amorphous alloy thin film of C0-zr-'rα, the main component of which is cobalt, on the plate. The alloy samples of each yuzu composition prepared in this manner are used for each characteristic test described below.

Figure 1 shows the coercive force (H
It is a characteristic diagram which shows the result of measuring the change of c). Therefore, in this figure, when the TG content is Oho state chi, Co
94 weight 9% -Zr 6 aij! % binary alloy. This alloy is also produced under similar conditions to those described above.

As is clear from this figure, 2 with Z'r added to CO
Although He is still high in the component alloy, by adding KTα to it, that is, Co-Zr-Ta
When it comes to a ternary alloy of , Hc suddenly decreases. Especially T
(L content is about 2% by weight or more, preferably about 5% by weight)
When it is above, He can be lowered to around 0.1 (Oe). When the content of TG is 5% by weight or more, the value of Hc is almost constant, and when the content exceeds 17 mm, the saturation magnetic flux density Bs of the ternary alloy becomes low, which is not preferable. Therefore, the content of TG in the alloy should be about 2~
It is better to limit the weight to 17 weights, preferably within a range of about 5 to 15 weights. It has been confirmed through experiments that this tendency remains the same even if the Zr content* changes somewhat.

In this way, by using a ternary alloy of co-Zr-Ta, Hc can be kept extremely low compared to a binary alloy of 1, Co alone or 1-JCo-Zr. Furthermore, the addition of Zr and TG greatly affects the magnetic permeability μ.

The lead 2 diagram is a characteristic diagram showing the results of measuring the relationship between the total content of Zr and TG and μ. As is clear from this figure, by adding Zr and Ta to Co, μ increases rapidly, and z
The total content of r and TcL is about 5 to 201 l.
! j+, μ can be made more than 4000, especially when the total content of Zr and Ta is about 8 to 17
Those in the heavy grade range have a part of μ, and an amorphous alloy with stable quality and high magnetic permeability can be obtained. The characteristics shown in FIG. 2 show the same tendency even if the weight ratio of Z'r and TCL is slightly changed.

Figure 3 is a characteristic diagram showing the results of measuring the relationship between the total content of Zr and Ta and Bs, and as in the case of Figure 2 q, the weight ratio of Zr and Ta is always zr:'rα-6 ,5:
W, i& is set so that it becomes 10.1. As is clear from this figure, as the total content of zr and Ta becomes redder, Bs tends to decrease, especially when the total content of zr and TCL exceeds about 20 tons.
SG;J, it becomes less than 10KG.

This characteristic shows a similar tendency even if the weight ratio of Zr and TcL changes somewhat.

As is clear from the characteristic curves in Figures 2 and 8), in order to obtain an amorphous alloy with small islands of μ and BS, the total content of Zr and rα must be adjusted to about 5 to 20% by weight.
It is best to regulate it within the range of .

Even if the total content of Zr and Ta is regulated in the range of approximately 5 to 20% by weight, if the Zr content is too low, an amorphous alloy with high Hc will result. Figure 4 shows
FIG. 3 is a characteristic diagram showing the results of measuring changes in Hc when varying the Zr content while keeping the Ta content in the alloy always at 100% by weight. Therefore, in this diagram, Z
When the content of r is 0% by weight, 0090wt 31%-T
It becomes a binary alloy with a content of 10ijf%. This alloy is also produced under substantially the same conditions as described above.

As is clear from this figure, C0KT (Z-doped 2
component alloys and Co with a Zr content of up to 2% by weight
-Zr-Ta ternary alloy is affected by Hc. However, when the Zr content exceeds about 25% by weight, Hc decreases rapidly, and when the Zr content exceeds about 5% by weight, He decreases to 1 (Oe).
It can be: In this way, Co-Zrr-T
In the ternary amorphous alloy of a, zr is approximately 25
By containing more than -weight, He can be kept low, but even if the content of zr becomes too high, the effect of keeping Hc low will be the same, but Bs will become lower on the contrary, which is not preferable. Therefore, in order to keep He low and Bs high, it is better to limit the Zr content to about 2.5 to 6.6% by weight, preferably about 5 to 6.5% by weight.

In the Co -z, -TcL based amorphous alloy according to the present invention, c is substituted with Nb which is a part of TtL.

-Zr-Ta-Nb four-component amorphous alloy if
It has excellent magnetic properties similar to the Co-Zr-Ta a+ffi amorphous alloy described above.

Figure 5 shows a graph containing 844% Co by weight and 611% by weight, the remaining 10% by weight consisting of rα and Nb, and N relative to Ta.
When the conversion ratio of b is varied, that is, CaB6
-z+r6- (Ta10G-xNbx)za is a diagram showing magnetic properties when the X value is variously changed.

In this figure, curve A shows the Hc characteristic, and curve B shows the μ characteristic. As is clear from this figure, c.

-Zr-Ta-Nb four-component amorphous alloy MoCo
-Zr(-Tcz) has almost the same excellent magnetic properties as the ternary amorphous alloy, but rather has Hc properties (song @A
) and Bs characteristics (song 11c> is slightly Co
-Better than Zr-Ta based amorphous alloy. This tendency 41 remains the same even if the contents of co and Zr change somewhat.

Even in this Co-Zr-Ta-Nb four-component amorphous alloy, by regulating the total content of zr-'rα-Nb to a range of about 5 to 20% by weight, an amorphous alloy with high μ and Bs can be made. Obtainable. Also, in this four-component amorphous alloy, the Zr content is about 2. ．． By regulating 5-fold 114 or more,
Hc can be kept extremely low.

Co-Zr-Ta system and Co-Zr- according to the present invention
For Ta-Nb alloys, the anisotropic magnetic field Hk of the alloy thin film formed by sputtering or vapor deposition is 15 to 20 (O
e) and large. As a result of various studies on ways to reduce this anisotropic magnetic field, we found that it is effective to heat treat an amorphous alloy thin film formed by sputtering, vapor deposition, etc. in a rotating magnetic field. In this process, the temperature is 300-400 (℃) and the rotation speed is 10-20℃.
(r, p, m.

), the magnetic field strength is preferably too (Oe) or more, and the processing time is preferably 3 hours or more. For example, the temperature is 350 (℃), the rotation speed is 1 o (r, p, m, ), and the magnetic field strength is 100
(Oe), and if one amorphous alloy thin film is processed with a processing time of 3 hours, the anisotropic magnetic field Hk will be approximately 4 (Oe).
It can be lowered to

FIG. 6 is an exploded perspective view of essential parts of a thin film magnetic reproducing head according to an embodiment of the present invention. l is a substrate made of non-magnetic material, 2
is an insulating coating, 3 is the first 8-air shield thin film, 4 is M R
(5 and 6 are conductive thin films) 7 is a second magnetic shield thin film.

As an example of the first magnetic shield thin film 3 and the second magnetic shield thin film 7, the CO content is 83.4,
C with a Zr content of 6.5% by weight, a Ta content of 10.1% by weight, and a total content of Zr and Ta of 16.6% by weight.
It consists of a three-component yarn amorphous alloy thin film of o-Zr-Tg. These magnetic shielding thin films 3 and 7 are each formed by sputtering, and then heat treated in a rotating magnetic field under the aforementioned conditions.

The other side of the magnetic shield thin film 31.7 has a CO inclusion rate of 8.
5% by weight, and the content of Zr, Ta, and Nb was 5% each, and the total content of Zr#Ta and Nb was 15%.
Quaternary amorphous alloy of Co-zrr-'rα-Nb in wt% f! It consists of a membrane. These magnetic shield thin films 3 and 7 are similarly formed by sputtering, and then heat treated in a rotating magnetic field under the above conditions.

As mentioned above, the present invention provides a magnetic shield thin film for a thin film magnetic reproducing head made of a three-component amorphous alloy containing cobalt as a main component and small amounts of zirconium and tantalum added thereto.
It is also characterized in that it is composed of a four-component amorphous alloy containing cobalt as a main component and to which small amounts of zirconium, tantalum, and niobium are added. These amorphous alloys have high magnetic permeability and saturation magnetic flux density, so they can fully exhibit the magnetic shielding effect, improve the playback feeling, and make it possible to further reduce the thickness of the magnetic shield thin film. is also possible.

[Brief explanation of the drawing]

Figure 1 is a characteristic diagram showing the relationship between niobium content and coercive force, Figure 2 is a characteristic diagram showing the relationship between total zirconium and niobium content and magnetic permeability, and Figure 3 is a characteristic diagram showing the relationship between zirconium and niobium total content and magnetic permeability. Figure 4 is a characteristic diagram showing the relationship between content and saturation magnetic flux density. Figure 4 is a characteristic diagram showing the relationship between zirconium and coercive force. Figure 5 is the magnetic characteristics when the amount of niobium substituted for tantalum is varied. Figures 6 and 6 are exploded perspective views of essential parts of a thin film magnetic reproducing head according to an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Substrate, 3... First magnetic shielding thin film, 4... MR element, 7... Second magnetic shielding t4° film . gISl Figure 0 5 lO1520To (
W t %) Figure 2 Q 5 10 15
20 25Zr+To (wt%) wS3 Figure 0 5 lOI5
20Zr+To(w Fig. 4 0 5 70
15 20Zr (wt%) Figures 5 to 6

Claims (1)

[Claims] (1) A thin film magnetic reproducing head in which magnetic shield thin films are formed on both sides of a magnetoresistive element,
A thin film magnetic reproducing head characterized in that the magnetic shield thin film is composed of an amorphous alloy of three-component threads containing J1 cobalt and to which small amounts of zirconium and tantalum are added. (2) In claim No. (j, paragraph 1),
The total content of zirconium and tantalum is about 5 to
A thin film magnetic reproducing head (8) characterized in that the content of zirconium is limited to 20% by weight of NtL. A thin film magnetic reproducing head characterized in that the cobalt magnetic reproducing head is regulated to about 2.5 fJj % S or more. A thin-film magnetic reproducing head characterized in that a three-component amorphous alloy thin film of Fn-tantalum is heat-treated in a rotating magnetic field. (6) Twilight magnetic reproducing head in which magnetic shielding thin films are formed on both sides of a magnetoresistive element. A thin III-layer magnetic reproducing head characterized in that the magnetic shield thin film is composed of a four-component amorphous alloy containing cobalt as a main component and to which small amounts of zirconium, tantalum, and niobium are added. (θ) A thin film magnetic reproducing head according to claim (6), characterized in that the total content of zirconium, tantalum, and niobium is regulated to a range of approximately 5 to 20 times Ijk. (7) Scope of Patent 1iM, Paragraphs (5) and (6)
), the zirconium content is about 25
A thin film magnetic reproducing head characterized in that its weight is restricted to - or more. (8) Claim (5) is characterized in that the four-component amorphous alloy thin film of cobalt-zirconium-tantalum-niobium formed as the magnetic shielding thin film is heat-treated in a rotating magnetic field. N demagnetized playback head.