JPS58105422A - Magnetic head - Google Patents

Abstract

PURPOSE:To avoid the eccentric wear and a burning phenomenon, etc. and to improve the durability for a magnetic head, by adding the impurities such as Ti, W, B, etc. to a basic composition of an alloy of high permeability which forms a magnetic layer. CONSTITUTION:A pair of magnetic core half bodies 11 and 12 are made of a ferrite material (such as Mn-Zn, Ni-Zn, etc.), and a magnetic layer 13 of a high permeability is formed on a gap forming surface of the core body 11. Then a working gap (g) is formed between the layer 13 and the other core body 12. The layer 13 is formed with a magnetic material obtained by adding Ti, W, B, Br, Cr, Nb, Mo, V, Ta, C, Hf, Zr, P, Mn, Ru, Sc, Y and >=1 kind of rare earth elements to a basic composition of the high-permeability magnetic material such as ''Sendust '' (Fe-Al-Si alloy) and then coated by a vapor deposit or sputter process. The thickness (t) of the layer 13 is preferably set at 3-20mu, and the amount of the above-mentioned elements to be added to the layer 13 is preferably set at 0.001-5wt%.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic head used in a magnetic recording/reproducing device.

In recent years, with the development of short wavelength recording technology, the coercive force (Hc) of magnetic tapes has continued to rise, and some metal tapes have a coercive force (Hc) of too much or more. On the other hand, with magnetic heads that record and play back data using high-magnetic tapes, there is a problem with sudden saturation of the head.
For this reason, it has been proposed that only the vicinity of the operating gap, where magnetic saturation is likely to occur, is made of a large alloy magnetic It material with a saturation magnetic flux density of Bg, such as a sendust film.
The figure shows a magnetic head previously proposed by the applicant, in which a pair of magnetic core halves (1) and (2) are made of ferrite material (for example, Mn-Za series, Ul-Zr series, etc.). 5 of the magnetic core body (1) and (2), arrow 1
In addition to the magnetic core body (1) on the escape side of the magnetic tape (3) running in the direction, a high permeability magnetic material layer (4) such as a Sendust film is applied to the TM which is brought into contact with the magnetic core body (2). It is formed by vapor deposition, sputtering, etc.

(7) is a gap Sveh tube. This magnetic head (5
), the magnetic core body (1) on the escape side of the magnetic tape
Since the K high permeability magnetic material layer (4) is formed, there is no magnetic saturation in the vicinity of the working gap g, making it suitable for use as a high magnetic strength tape. In addition, since the high magnetic permeability material layer (4) is continuously formed from the tape contact surface to the rear gap part beyond the winding hole (6), the reproducing magnetic flux is continuous during reproduction. The magnetic material passes through the uniform high permeability magnetic material layer (4), and the influence of the large instantaneous resistance of the high permeability magnetic material layer-7 elite field is reduced, improving reproduction efficiency.

However, in a magnetic head using such a composite core, as shown in FIG. Due to the gap d, the contact between the magnetic tape and the magnetic head is still insufficient, and the head output on the short wavelength side decreases. In addition, as the magnetic tape runs, the sendust layer (
A so-called burn-in phenomenon occurs in which the binder mainly adheres to the magnetic tape side in the 4) area, which creates an effective gap between the magnetic tape and the magnetic head, and similarly reduces the head output on the short wavelength side. . Such uneven wear and seizure phenomena are fatal to the above-mentioned composite core magnetic head, and have caused a great deal of trouble in commercialization.

In view of the above-mentioned points, the present invention provides a magnetic head with excellent durability by preventing uneven wear and seizure phenomena in a so-called composite core having a magnetic layer with high magnetic permeability near the working gap. It is something.

The present invention provides a magnetic head comprising a pair of magnetic core bodies and having a high permeability magnetic layer on the gap forming surface, in which the magnetic layer is made of a high permeability alloy with a basic composition of a specific element (Tm*W).
*B*Br ecr tNbtMOeV*Ta tct
Hf tZr tPthh * Ru * 8c *
The magnetic layer has a magnetic layer formed by vapor deposition or sputtering mixed with one or more of Y and rare earth elements, and is designed to prevent uneven wear and seizure in the magnetic head.

Embodiments of the present invention will be described in detail below with reference to the drawings.

According to the present invention, for example, as shown in FIG.
- Zn system, Ni-Zn system), and a high magnetic permeability magnetic layer I is formed on the gap forming surface of one of the magnetic core halves aυ and a poor half aυ of the magnetic core half aυ. A working gap g is formed between I and the other magnetic core halves (J2J).

In this case, the magnetic core center aυ to which the magnetic layer α is adhered is the magnetic core center on the escape side of the magnetic tape running in the direction of arrow 1, and the magnetic layer I is closer to the winding hole than the tape contact surface. In this example, the entire length VCIL of the magnetic core body αυ is formed continuously so that it reaches the rear gear part aeK beyond the distance VCIL.

Therefore, the magnetic layer has a basic composition of a high magnetic permeability material such as Sendas (Fe-Al-8i alloy) K Ti't
W*BtBr*Cr5Nb*MO*VyTa*CtHf
t Zr t PJan tRtt * Sc *Y
It is made of a magnetic material doped with one or more of rare earth elements and is deposited by vapor deposition or sputtering. The thickness t of this magnetic layer a1 is preferably 3μ to 20μ. Also, the amount of the above elements added to the magnetic layer 03 is 0.001
The range is preferably from 5% by weight to 5% by weight. The table below shows the optimum addition amount for each element.

In addition, in the case of a sputtering cylinder, the method for forming the magnetic layer a is, for example, a method using a single target (base material) made by adding the desired amount of the above-mentioned desired element, ie, an impurity, to the composition of Sendust, or There is a method using a so-called composite target in which an impurity is placed on the target, and a method in which a binary target is used in which a sendust target is placed on the first cathode and an impurity is placed on the second cathode. Various methods can be considered for forming the magnetic layer I by vapor deposition. For example, there is a method in which a sendust crucible and an impurity crucible are arranged separately, and the temperature of each crucible is independently controlled to perform vapor deposition.

By using the magnetic head according to the present invention, coercive force (Hc
) 13000e metal chive with relative speed 3.5
Figure 4 shows the recording and reproducing characteristics when running at m/w-. In the figure, curve (A) is the magnetic head of the present invention, curves (B) and (C) are the magnetic head of Figure 1 without additive elements, and curve (B) is the magnetic head in its initial use state. , i! Fill (C) is a case of sufficient usage.

As is clear from this characteristic diagram, in the case of the magnetic helad in Fig. 1, the head output on the short wavelength side decreases under sufficient use conditions, but with the magnetic head of the present invention, even under sufficient use conditions, the head output on the short wavelength side decreases. The side head output did not decrease, and the characteristics improved.

FIG. 5 is a characteristic diagram in which durability was investigated, and track H (E) shows the magnetic head according to the present invention shown in FIG. 3, and track # (D) shows the magnetic head shown in FIG. 1. In the magnetic head shown in Fig. 1, a burn-in phenomenon occurred before the tape was run less than 100 times, and the head output sharply decreased, but the magnetic head of the present invention can reach over 1000 times. Ta.

According to the present invention, in a magnetic head comprising a composite core having a high permeability magnetic layer near the working gap, the basic composition of the high permeability alloy constituting the magnetic layer is T.
By adding impurities such as +t Wt B, uneven wear and seizure phenomena can be prevented, and a magnetic head with excellent durability can be obtained.

Incidentally, a magnetic head with a parter structure in which a desired additive element is added to Cefdust has been proposed, but in this case, the addition of the additive element causes a decrease in magnetic permeability and a slight decrease in the saturation flux density of 813. The decline was fatal. However, in the present invention, since the magnetic layer I having a thickness of 3 μm to 20 μm is deposited on the ferrite core half a1) by vapor deposition or sputtering, the magnetic layer I is 0 μm thick when viewed as a whole.
The decrease in magnetic permeability μ and saturation magnetic flux density Bs at
This does not lead to deterioration of reproduction characteristics or short wavelength recording characteristics.

In addition, in the clay figure, it was applied to a magnetic head in which a high permeability magnetic layer α was formed only on the gap forming surface of one magnetic core half body aυ, but in other cases, as shown in Fig. 6, both magnetic core half bodies aυ
A high permeability magnetic layer α3 is formed on each gap forming surface of α and α.
Of course, the present invention can also be applied to a magnetic head formed with a.

[Brief explanation of the drawing]

1 and 2 are a front view and an enlarged view of the main parts of a magnetic head for explaining the present invention, FIG. 3 is a front view showing an embodiment of the magnetic head according to the present invention, and FIGS. FIG. 5 is a recording/reproducing characteristic diagram and a characteristic diagram showing durability, respectively, to explain the present invention, and FIG. 6 is a front view showing another embodiment of the present invention. αDa2 is the magnetic core half-dead, I is the high permeability magnetic layer, (g
) is the operating gap 1.

Claims (1)

[Claims] A magnetic head consisting of a pair of magnetic core bodies [, high permeability magnetic material KTi sW, BtBr, ClNb5M0
sV*TatCtHfsZrtP*MntR4l*8C
A magnetic head comprising a magnetic layer formed by vapor deposition or sputtering of a material containing at least one of tY and rare earth elements on at least one of the gap forming surfaces of the magnetic head.