JPH06240417A - Magnetic alloy - Google Patents

Abstract

PURPOSE:To provide a magnetic alloy ensuring satisfactory soft magnetic characteristics by imparting a compsn. represented by a specified formula. CONSTITUTION:A compsn. represented by a formula FeaNbAlc (where a+b+c=100 atomic %, 5<=b<=10 and 3<=c<=10) or FeaNbAlcMd (where a+b+c+d=100 atomic %, 5<=b, 3<=c<=10, 0.3<=d<=3 and M is one or more kinds of elements selected among Ti, V, Cr, Ni, Cu, Y, Zr, Nb, Mo, Ru, Rh, Pd, PAg, Sn, Sb, Hf, Ta, W, Re, Os, Ir, Pt, Au and Pb) is imparted to a magnetic alloy. The objective soft magnetic alloy having excellent corrosion resistance can be provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic alloy for a magnetic device such as a magnetic head which is particularly suitable for high density magnetic recording.

[0002]

2. Description of the Related Art In recent years, there has been an increasing need for higher density and wider band of magnetic recording. Therefore, by using a magnetic material having a high coercive force as a magnetic recording medium and narrowing the recording track width, high density recording can be achieved. It realizes magnetic recording and reproduction.
Then, as a magnetic head material for magnetic recording and reproduction on the magnetic recording medium having the high coercive force, a saturation magnetic flux density B
Since a magnetic alloy having a high s is required, a magnetic head using a sendust alloy, an amorphous alloy or the like for a part or all of the core has been proposed.

However, the coercive force of the magnetic recording medium is further increased, and the coercive force of the magnetic recording medium is, for example, 2000.
When it is Oe or more, it becomes difficult to perform good magnetic recording / reproduction with a magnetic head using a sendust alloy or an amorphous alloy. A perpendicular magnetic recording method has also been proposed in which the recording is performed by magnetizing in the thickness direction of the magnetic recording medium rather than in the longitudinal direction. However, in order to perform good recording by this perpendicular magnetic recording method, the main magnetic head used is The thickness of the tip of the magnetic pole needs to be 0.5 μm or less, and even when recording on a magnetic recording medium having a relatively low coercive force, a magnetic alloy for a magnetic head having a high saturation magnetic flux density is required.

Then, as a magnetic alloy for a magnetic head having a higher saturation magnetic flux density than a sendust alloy or an amorphous alloy, F
An eN-based magnetic alloy is known. Some magnetic head structures, such as a metal-in-gap (MIG) type and a laminated type, include a glass mold process in the manufacturing process thereof. These general schematic configuration diagrams are shown in FIGS. 1 and 2, respectively. In such a magnetic head,
For a glass mold, glass having a softening point of 500 ° C. or higher is used in terms of reliability such as adhesive strength and weather resistance.

Therefore, it is necessary that the magnetic material used as the core material of these magnetic heads is stable even at a high temperature heat treatment of 500 ° C. or higher and has sufficient soft magnetic characteristics as a magnetic head. The soft magnetic characteristics required for the magnetic head are such that when a Sendust alloy, an amorphous alloy, a permalloy alloy, or the like is used, the coercive force Hc ≦ 0.5 Oe in these magnetic films formed on the substrate, Permeability μ ≧ 2000 and magnetostriction λs˜0. If the magnetic characteristics are inferior to this, the recording and reproducing efficiency of the magnetic head is lowered and the magnetic head noise is increased, and it becomes difficult to obtain a magnetic head having good electromagnetic conversion characteristics.

[0006]

By the way, a FeN-based magnetic alloy is known as a magnetic alloy for a magnetic head having a higher saturation magnetic flux density Bs than a sendust alloy, an amorphous alloy or the like. In this regard, the inventors of the present invention have proposed a magnetic alloy for a magnetic head having a high Bs of 15 kG or more, which is obtained by selecting the N and Al content ratios in the FeN-Al alloy (Japanese Patent Application No. 2-35762). No.).

Among the magnetic alloys related to this proposal, 50
Although some of the materials maintain excellent soft magnetic properties even after heat treatment at a high temperature of 0 ° C. or higher, the disclosed composition range is defined based on the characteristics after heat treatment at 300 ° C.
It does not necessarily guarantee that good soft magnetic properties can be obtained even after the heat treatment at 500 ° C. or higher within the disclosed composition range.

Therefore, according to the present invention, good soft magnetic properties can be obtained even after heat treatment at a high temperature of 500 ° C. or higher, and 1
It is an object of the present invention to provide a soft magnetic alloy having a high Bs of 5 kG or more and further a soft magnetic alloy having excellent corrosion resistance in practical use.

[0009]

The present invention has been made in order to achieve the above-mentioned object, and the following 1) to 3) are provided.
The present invention provides a magnetic alloy having the above structure. That is, 1) Fe _a N _b Al _c is represented by a composition formula, and a, b, c
A magnetic alloy having an atomic% represented by 5 ≦ b ≦ 10 3 ≦ c ≦ 10 a + b + c = 100. 2) represented by the composition formula Fe _a N _b Al _c M _d , a,
A magnetic alloy in which the atomic% represented by b, c, d has a relationship of 5 ≦ b ≦ 10 3 ≦ c ≦ 10 0.3 ≦ d ≦ 3 a + b + c + d = 100. However, M is Ti, V, C
r, Co, Ni, Cu, Y, Zr, Nb, Mo, Ru,
Rh, Pd, Ag, Sn, Sb, Hf, Ta, W, R
At least one element selected from the group consisting of e, Os, Ir, Pt, Au, and Pb. 3) The magnetic alloy according to claim 1, which has a relationship of 0.3c + 2.6 ≦ b ≦ 0.4c + 3.8.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. First, a magnetic material manufacturing apparatus according to an embodiment of the present invention will be described. FIG. 3 is a schematic configuration diagram of a manufacturing apparatus for explaining an embodiment of the magnetic alloy of the present invention.
In FIG. 3, 1 is a nitrogen flow meter, 2 is an argon flow meter, 5 is a target, 6 is a magnet, 7 is an insulator, 8 is cooling water, and 9 is a target holder. 10, 10 is a shutter, 11 is a substrate, 12 is a substrate holder, 13
Is a DC power source, 14 is plasma, and 15 is a vacuum chamber. The pair of targets 5 and 5 is an alloy target of Fe and Al, or a composite target in which chip-like Al is fitted into the recess of a pure iron target provided with an appropriate recess.
It is a get.

Each of these targets 5 and 5 is a target.
The target holders 9 and 9 are supported, and a negative potential is applied from the DC power supply 13 to the target holders 5 and 5 and the target holders 9 and 9, and these target holders 9 and 9 are further applied. Magnets 6, 6 for converging the plasma 14 are inserted in the interior of the chamber, and cooling water 8 for preventing heating of the surfaces of the targets 5, 5 is circulated.

Two target holders 9, 9 are provided on the left and right of the grounded vacuum chamber 15 and insulated from the vacuum chamber 15 by insulators 7, 7. In addition, nitrogen (N ₂ ) and argon (Ar) are introduced from the upper part of the vacuum chamber 15 with the flow rate 1 for nitrogen and the flow meter 2 for argon adjusted to predetermined flow rates. Argon generates plasma 14 and the target 5,
Simultaneously with sputtering No. 5, the amount of nitrogen in the magnetic alloy film to be formed is adjusted. And the vacuum tank 15
A substrate 11 is placed on a substrate holder 12 below the substrate, and a shutter 10 for preventing impurities covers the substrate 11. As described above, the magnetic alloy production apparatus is roughly configured.

Next, the outline of the method for producing this magnetic alloy will be described. In this manufacturing apparatus, the DC power supply 13
Plasma 14 is generated between the targets 5 and 5 supported by the left and right target holders 9 and 9. At this time, since the targets 5 and 5 have a negative potential, the argon ions (Ar ⁺ ) in the plasma 14 are
5 and collides with the target 5, 5 and Fe atoms and Al
Atoms pop out. Then, the atoms of Fe and Al jumping out from the targets 5 and 5 are combined with the nitrogen atoms or molecules in the plasma 14 to grow on the substrate 11.
Note that the shutter 10 is closed and the substrate 11 is covered for several minutes after the start of sputtering so that impurities on the surfaces of the targets 5 and 5 do not adhere to the substrate 11 and the shutter 10 is opened thereafter. .

Then, by adjusting the introduction amounts of nitrogen and argon by the nitrogen flow meter 1 and the argon flow meter 2, respectively, Fe _a N _B A containing the desired amount of nitrogen is obtained.
An l _c alloy can be obtained. In the case of obtaining an Fe _a N _B Al _c M _d alloy, elements corresponding to Fe, Al and M (M
o, Ru, etc.) alloy targets may be used. Also,
The magnetic alloy of the present invention can also be manufactured by using another film forming method, for example, an RF magnetron sputtering method, an ion beam sputtering method, an EB vapor deposition method or the like.

Next, the relationship between the added amount of Al and the magnetic characteristics in one embodiment of the magnetic alloy of the present invention will be described.
FIG. 4 is a graph showing the relationship between the coercive force Hc and the amount of Al added in one example of the magnetic alloy of the present invention. Here, the nitrogen amount is kept constant at 6.3 at% and the characteristics after the heat treatment at 550 ° C. are shown. The nitrogen content is T
It was determined by quantitative analysis using EPMA (electron probe microanalyzer) and XPS (X-ray photoelectron spectroscopy) using the iN substrate as a standard sample, but ± 20
% Error is expected. In the range of the added amount of Al shown in FIG. 4, coercive force Hc ≦ 0.5 Oe, and an excellent soft magnetic film can be obtained.

FIG. 5 is a graph showing the relationship between the saturation magnetic flux density Bs and the amount of Al added in one embodiment of the magnetic alloy of the present invention. Here, the nitrogen amount is kept constant at 6.3 at% and the characteristics after the heat treatment at 550 ° C. are shown. Figure 5
In the range of the Al addition amount shown in (1), the saturation magnetic flux density Bs is 15 kG or more, and an excellent soft magnetic film having sufficient magnetic characteristics for high density magnetic recording can be obtained. However, A
When the added amount of 1 is less than 3 at%, the coercive force Hc rises sharply, and when the added amount of Al exceeds 10 at%, the saturation magnetic flux density Bs decreases, so that a soft magnetic film required for high density magnetic recording can be obtained. It's gone.

FIG. 6 is a graph showing the relationship between the coercive force Hc and the heat treatment temperature in one example of the magnetic alloy of the present invention. Here, the results are shown when the amount of nitrogen is 6.3 at% and the amount of Al added is 9.3 at%. However, by adding an appropriate amount of Al, the coercive force Hc becomes small even with heat treatment at 600 ° C. As shown in the figure, it can be seen that a soft magnetic alloy for a magnetic head having sufficient heat resistance, which hardly causes deterioration of magnetic characteristics even in a high temperature glass molding process during a predetermined magnetic head manufacturing process, can be obtained. Thus, Fe
By adding 3 to 10 at% of Al to the N film, B
A soft magnetic alloy for a magnetic head having s ≧ 15 kG, Hc ≦ 0.5 Oe and excellent heat resistance can be obtained.

FIG. 10 is a graph showing the relationship between the nitrogen and Al contents and the coercive force Hc in one embodiment of the magnetic alloy of the present invention. Here, in the Fe-N-Al film, the nitrogen and Al contents were changed, and when the coercive force Hc after the heat treatment at 550 ° C was Hc ≤ 0.5 Oe, ◯, 0.5.
When <Hc ≦ 3.0 Oe, it is indicated by Δ, and when Hc> 3.0 Oe, it is indicated by ●. It can be seen that in the range of 3 to 10 at% of Al and 5 to 10 at% of nitrogen, soft magnetic properties sufficient as a magnetic alloy for a magnetic head having a high temperature heat treatment step are exhibited.

FIG. 7 is a graph showing the relationship between the nitrogen content and the coercive force Hc, the saturation magnetic flux density Bs or the magnetostriction λs in one embodiment of the magnetic alloy of the present invention. here,
The results are shown when heat treatment was performed at 550 ° C. with the amount of Al added being kept constant at 8.0 at%. From FIG. 7, it is understood that when the nitrogen addition amount is 5 to 10 at%, an excellent soft magnetic film with Hc ≦ 0.5 Oe is obtained. At this time,
Bs is also about 18 kG, which is a very high value.
On the other hand, the magnetostriction λs is in the range of -1 × 10 ^-6 to 4 × 10 ^-6 , which means that the λs can be controlled while maintaining the high Bs and the low Hc. But 5.1
~ 7.0at%, | λs | ≦ 1 × 10 ^-6 ,
It is possible to obtain a soft magnetic alloy for a magnetic head that has particularly excellent electromagnetic conversion characteristics.

FIG. 8 is a graph showing the relationship between magnetostriction λs and nitrogen content in one example of the magnetic alloy of the present invention. Here, the amount of Al added is set to 55 as a parameter.
The results after heat treatment at 0 ° C. are shown. When the amount of Al added is changed, the range of the amount of nitrogen such that | λs | ≦ 1 × 10 ⁻⁶ changes depending on the amount of added Al. │λs│ ≦ 1 ×
The range of 10 ⁻⁶ shifts to the side with a large amount of nitrogen as the added amount of Al increases.

FIG. 9 is a graph showing the relationship between nitrogen and Al contents and magnetostriction λs in one example of the magnetic alloy of the present invention. The shaded area in FIG. 9 is | λs | ≦
The range is 1 × 10 ⁻⁶ . The formula is as follows.

[0022]

[Equation 1]

However, b and c are nitrogen and Al, respectively.
The content at% is shown. Further, as shown in FIGS. 4 and 7 above, in the range of | λs | ≦ 1 × 10 ⁻⁶ ,
Hc ≦ 0.5 Oe, indicating excellent soft magnetic properties. Therefore, by controlling the nitrogen content and the Al content within the ranges shown in the above formulas, a soft magnetic alloy having low Hc, low λs, high Bs and heat resistance can be obtained.

Next, the corrosion resistance of one embodiment of the magnetic alloy of the present invention will be described. Table 1 is a table showing the effect of additive elements such as Ti and Cr on the corrosion resistance in one example of the magnetic alloy of the present invention.

[0025]

[Table 1]

In Table 1, the item of corrosion resistance evaluation shows experimental results of corrosion resistance, and after the sample was left for 1000 hours in a constant temperature bath set at a temperature of 60 ° C. and a humidity of 90%, corrosion marks were left. Corrosion resistance was indicated by ◯ for those not seen, Δ for those with slight corrosion marks, and X for those with many corrosion marks. At the same time, when the additional element is added, the coercive force among the soft magnetic properties is most affected, so the value of the coercive force is also shown. Sample No. 21 is a comparative example FeN
Alloy, sample number 22 is Fe-N-Al alloy, sample number 2
3 to 52 are Fe-N-Al alloys to which elements such as Ti and Cr are added, and sample numbers 22 to 52 are magnetic alloys according to the present invention. Here, if the total content of Ti, Cr, etc. is less than 0.3 at%, no remarkable effect on the corrosion resistance is observed, while if it exceeds 3 at%, as shown in the table, as shown in the table, The magnetic properties cannot be obtained.
Therefore, Ti, V, Cr, Co, Ni, Cu, Y, Z
r, Nb, Mo, Ru, Rh, Pd, Ag, Sn, S
b, Hf, Ta, W, Re, Os, Ir, Pt, Au,
When the total content of Pb is 0.3 to 3 at%, a magnetic alloy having excellent soft magnetic characteristics and corrosion resistance can be obtained.

[0027]

As described above, according to the magnetic alloy of the present invention according to claim 1, even when a magnetic head is manufactured by performing a high temperature treatment at 500 ° C. or higher, a low coercive force Hc and a high saturation magnetic flux are obtained. It is possible to provide a magnetic alloy that can obtain good soft magnetic properties without impairing the density Bs. Further, according to the magnetic alloy of the present invention according to claim 2, in addition to the effect of the magnetic alloy according to claim 1, it is possible to provide a magnetic alloy excellent in corrosion resistance. Further, according to the magnetic alloy of the present invention according to claim 3, in addition to the effect of the magnetic alloy according to claim 1 or 2, even when a magnetic head is manufactured by performing a high temperature treatment at 500 ° C. or higher, It is possible to provide a magnetic alloy that can obtain good soft magnetic properties without impairing the magnetostriction λs.

[Brief description of drawings]

FIG. 1 is a perspective view showing a general example of a metal-in-gap (MIG) type magnetic head.

FIG. 2 is a perspective view showing a general example of a laminated magnetic head.

FIG. 3 is a schematic configuration diagram of a manufacturing apparatus for explaining an embodiment of the magnetic alloy of the present invention.

FIG. 4 is a graph showing the relationship between coercive force Hc and Al addition amount in one example of the magnetic alloy of the present invention.

FIG. 5 is a graph showing the relationship between the saturation magnetic flux density Bs and the amount of Al added in one example of the magnetic alloy of the present invention.

FIG. 6 is a graph showing the relationship between coercive force Hc and heat treatment temperature in one example of the magnetic alloy of the present invention.

FIG. 7 is a graph showing the relationship between the nitrogen content and the coercive force Hc, the saturation magnetic flux density Bs or the magnetostriction λs in one example of the magnetic alloy of the present invention.

FIG. 8 shows magnetostriction λ in one example of the magnetic alloy of the present invention.
It is a graph which shows the relationship between s and nitrogen content.

FIG. 9 is a graph showing the relationship between nitrogen and Al contents and magnetostriction λs in one example of the magnetic alloy of the present invention.

FIG. 10 is a graph showing the relationship between nitrogen and Al contents and coercive force Hc in one example of the magnetic alloy of the present invention.

[Explanation of symbols]

 1 Nitrogen Flowmeter 2 Argon Flowmeter 5 Target 6 Magnet 7 Insulator 8 Cooling Water 9 Target Holder 10 Shutter 11 Substrate 12 Substrate Holder 13 DC Power Supply 14 Plasma 15 Vacuum Chamber

Claims (3)

[Claims] 1. A compositional formula of Fe _a N _b Al _c ,
A magnetic alloy in which atomic% represented by a, b, and c has a relationship of 5 ≦ b ≦ 10 3 ≦ c ≦ 10 a + b + c = 100. 2. The atomic% represented by the composition formula Fe _a N _b Al _c M _d , represented by a, b, c, and d, is 5 ≦ b ≦ 10 3 ≦ c ≦ 10 0.3 ≦ d ≦ 3 A magnetic alloy having a relationship of a + b + c + d = 100. However, M is Ti, V, C
r, Co, Ni, Cu, Y, Zr, Nb, Mo, Ru,
Rh, Pd, Ag, Sn, Sb, Hf, Ta, W, R
At least one element selected from the group consisting of e, Os, Ir, Pt, Au, and Pb. 3. 0.3c + 2.6 ≦ b ≦ 0.4c + 3.8
The magnetic alloy according to claim 1 or 2, having the following relationship.