JPS6244683B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a magnetic head, and more particularly, an object of the present invention is to provide a magnetic head using an improved magnetic alloy so as to be applicable to high-density recording tapes. Conventional magnetic materials used in magnetic heads include sendust, permalloy, and ferrite. However, recently, magnetic tapes with high coercive force such as metal tapes have been developed, but if a magnetic head is manufactured using the conventional magnetic materials mentioned above for this type of magnetic tape and used, magnetic There is a risk that saturation may occur and recording characteristics may be impaired. For magnetic tapes with high coercive force such as metal tapes, it is desirable to use magnetic materials with higher saturation magnetic flux density (B _S ) than the above-mentioned materials. Magnetic head designers require B _S of 12KG (1.2T) or more, preferably
The magnetic material is 15KG (1.5T) or more, but up until now we have been forced to use magnetic materials that are less than 15KG (1.5T). So-called permendicol, which has a composition of 50% iron (by weight, same hereinafter) and 50% cobalt, has been known as a magnetic material with an extremely high B _S .
Although this material has a high B _S , other magnetic and electrical properties are not suitable for use in magnetic heads, and for this reason it has not been used as magnetic heads. That is, in addition to high B _S , magnetic head materials are required to have high magnetic permeability (μ ₀ ) and low coercive force (H _C ). The required characteristics differ depending on the type of magnetic head and cannot be determined unconditionally. In particular, with the progress of IC, the magnetic permeability (μ ₀ ) has become good even if it is quite low, but even so, the μ 0 of the 50Co-50Fe alloy
If ₀ is around 1000, it will be difficult. Also, considering the problem of magnetization, the problem is large and difficult for several Oe of 50Co-50Fe alloy. Furthermore, materials for magnetic heads are required to have high electrical resistance in order to reduce eddy current loss in the high frequency range, but the electrical resistance (volume resistivity) ρ of 50Co-50Fe alloy is smaller than that of permalloy, etc. . This invention was made with this in mind.
The present invention provides a magnetic head for a high coercive force magnetic tape that performs high density recording. i.e. 25-70%
Cobalt (Co)-iron (Fe) based alloy, chromium (Cr), tungsten (W), molybdenum (Mo),
At least one of tantalum (Ta), manganese (Mn), niobium (Nb), copper (Cu), vanadium (V), germanium (Ge), aluminum (Al), silicon (Si), and titanium (Ti). A magnetic head is made of a magnetic alloy with 10% or less addition (added by replacing a portion of Fe) to improve permeability and coercive force without significantly reducing saturation magnetic flux density, and further increase electrical resistance. It forms the In an iron-cobalt material, B _S is the largest when the cobalt content is about 30% and the balance is iron, but the magnetic permeability (μ ₀ ) is largest when the cobalt content is about 50% and the balance is iron. Therefore, in this invention as well, it is preferable that the amount of cobalt and the amount of iron be equal, but in practice there is no problem if it is about 25 to 70%, and the amount of cobalt added is 25 to 70%, preferably 45%.
~55%. Cr, W, Mo, Ta, Mn, Nb, Cu, V, Ge,
Adding at least one of Al, Si, and Ti in a total amount of 10% or less has a great effect on improving magnetic properties such as lowering coercive force (H _C ) and improving magnetic permeability (μ ₀ ). , and increases electrical resistance (ρ). However, if the total amount exceeds 10%, the saturation magnetic flux density (B _S ) decreases, making it less useful as a magnetic head for high coercive force magnetic tapes, and the magnetic permeability tends to decrease. % or less. An embodiment of this invention will be described below. Hot and cold processing is performed on ingots dissolved in predetermined ingredients.
A ring sample with an outer diameter of 10 mm and an inner diameter of 6 mm was cut from a plate material with a thickness of mm, and was heat-treated to measure the material properties.A special head for industrial use was also fabricated to determine the characteristics at high input and magnetization. Examined. The characteristics of the magnetic head of the present invention and a conventional magnetic head made of permalloy or the like were compared under the same conditions. The results are shown in Table 1 below.

【table】

[Table] In this table, sample numbers 1 to 16 are of the present invention, and sample numbers 17 and 18 are of the conventional example. As is clear from this table, the magnetic head of the present invention has significantly higher B ₁₀ (i.e., B _S ) than conventional magnetic heads made of permalloy, etc., and as a result, it is possible to obtain a high output level even at high input. Can be done. Also, magnetization is improved compared to the 50% Co alloy core. That is, the magnetic head of this invention is
The core material used is an Fe-Co alloy that has a saturation magnetic flux density that is much higher than conventional magnetic head materials, has sufficiently high magnetic permeability, sufficiently low coercive force, and has increased electrical resistance. If used as a magnetic head for a high coercive force magnetic tape, the performance of the tape can be fully brought out, making it extremely useful industrially.

Claims (1)

[Claims] 1 25-70% cobalt, chromium, tungsten,
Molybdenum, tantalum, manganese, niobium, copper,
10% of at least one of vanadium, germanium, aluminum, silicon, and titanium in total
The following describes a magnetic head for a high coercive force magnetic tape using a magnetic alloy with the balance being iron as a core material.