JPS63100147A - Ni-fe-base alloy for vapor deposition - Google Patents

Abstract

PURPOSE:To stably and efficiently obtain a magnetic thin film combining high purity with superior characteristics, by incorporating specific amounts of Al, Ca and/or Mg, O, and N to an Ni-Fe-base alloy for vapor deposition. CONSTITUTION:The Ni-Fe-base alloy for vapor deposition has a composition consisting of, by weight, 35-85% Ni, <=1% Al, <=300ppm Ca and/or Mg, <=30ppm O, <=30ppm N, and the balance essentially Fe and further containing, if necessary, <=1% Ti. In this alloy, impurity content is minimized and further, owing to gettering action by Ca and/or Mg and by Al and Ti, gas components in a vapor deposition atmosphere can be reduced. This alloy is useful as vapor deposition material for manufacturing thin film of high permeability material.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a Ni-Fe-based alloy for vapor deposition, and in particular to the production of thin films used as head materials and base materials for magnetic recording materials by utilizing its high magnetic permeability. The present invention relates to an N1-Fe-based alloy suitable for vapor deposition.

[Prior Art] A magnetic recording material in which a magnetic alloy thin film is formed on a nonmagnetic substrate is well known.

Vapor deposition methods such as sputtering, vacuum evaporation, and ion blating are widely used as methods for producing thin films of magnetic recording materials.

In particular, the sputtering method is advantageous in that it is possible to obtain a compositionally uniform thin film while controlling the pressure inside the sputtering device, as long as a target material containing a certain alloying element with a uniform internal composition is obtained. be.

As ferromagnetic alloys that form magnetic alloy thin films, nickel alloys, cobalt alloys, iron alloys, etc. have been used conventionally, but among these, Ni-Fe-based alloys have a high magnetic permeability, so various types of alloys have been used. is being put into practice. For example, N
1-Fe-based 35-90% Ni alloy is called Permalloy as an alloy with high magnetic permeability.
In particular, 70-80% Ni alloy is called Permalloy A.
(PA), with an initial permeability μ0 and a maximum permeability μ in a weak magnetic field.
m is large. Particularly in recent years, it has attracted attention as a base material for perpendicular magnetic recording materials, along with thin-film heads.

[Problems to be solved by the invention] After conducting various studies on conventionally used magnetic alloys, we found that they contain relatively large amounts of inclusions such as oxygen, nitrogen, sulfur, carbon, and other metal oxides. It has been recognized that this has a significant adverse effect on the magnetic properties of the resulting thin film.

[Means for Solving the Problems] In view of the above-mentioned conventional circumstances, the present invention provides an N 1-Fe-based alloy for deposition, which can stably and efficiently obtain a high-performance magnetic thin film with a low impurity content. Ni 35-85% by weight, An 1% by weight or less, Ca and/or
or MMg 300pp or less, 030ppm or less, 830
ppm or less, and the balance is substantially Fe, and 35 to 85% by weight of Ni, 21% by weight or less of A, 1% by weight or less of Ti, and 300pp or less of Ca and/or MMg. ,030
ppm or less, 30 ppm or less of NN, and the remainder is substantially F'e.

That is, as a result of extensive studies in order to solve the problem caused by impurities in the deposition alloy and obtain a high-characteristic magnetic thin film, the present inventors found that a specific amount of Ca and /or Mg and Al2. Alternatively, by containing An and Ti, an alloy with low impurity content can be obtained, and moreover, an alloy containing Ca and/or Mg and Al2 and/or Ti can be obtained.
The present invention has been completed based on the discovery that the gettering effect of the above method can also reduce the gas components in the deposition atmosphere and obtain a magnetic thin film with extremely high purity and high characteristics.

Hereinafter, the present invention will be explained in detail.

In addition, in this specification, "%" represents "weight%."

The N1-Fe-based alloy for vapor deposition of the present invention is used as a material for vapor deposition in vacuum vapor deposition, sputtering, ion blating, etc., and is used for manufacturing magnetic thin films, etc., and its composition is as follows. That's right.

Ni: 35-85% Fe: Balance A1: 1% or less Ti: Not contained (first invention) or 1% or less (second invention)
invention) Ca and/or Mg: 300 ppm or less 0:3
0 ppm or less N: 30 ppm The reason for limiting the alloy composition of the present invention will be explained below.

In the Ni-Fe-based alloy for vapor deposition of the present invention, Ni is 35
~85%. This means that in this range of Ni content,
This is because extremely high magnetic permeability can be obtained, and N is preferable.
By setting the i content to 70 to 85%, particularly 78.5%, a significantly high magnetic permeability can be obtained.

Ai and Ti are mixed with Ca, Mg when melting the alloy.
It also acts to clean the alloy and has a getter effect to trap gas components in the deposition atmosphere. However, A11
%Ti is so large that it is not preferable to have an effect on the alloy properties. Therefore, in the present invention, each is set to 1% or less. Naturally, Afl
, Ti, if the amount thereof is too small, the sufficient effects of the above-mentioned cleaning action and getter action cannot be obtained. In the present invention, Al0.005 to 0. 5%, or Aug, 005~0.5% and Ti0.5% or less, more preferably Al1g, 05~0.2%, Alui is A
ft, 0.5 to 0.2% and Ti, preferably 0.2% or less. Note that since Al2 or Ti exhibits the effects of the present invention by existing in the alloy in the form of solid solution A1 or solid solution Ti, the existence form of Al2 or Ti may be in the solid solution state. is important.

As mentioned above, Ca and Mg act together with Al and/or Ti to clean the alloy and also act as a getter. If the content of Ca and Mg is too large, it may affect the properties of the alloy and may also cause the alloy to become brittle due to the precipitation of intermetallic compounds.

Therefore, in the present invention, the content of Ca and/or Mg is set to 300 ppm or less. On the other hand, Ca and/or M
Even if the content of g is too low, it still contains Ca.

Sufficient cleaning and gettering effects by Mg do not appear. From this, the Ca%Mg content is 5
~1100pp, preferably 10-50pp each
It is preferable that the range is in the range of It is important that the existing forms of Ca and Mg in the alloy are metallic Ca and metallic Mg.

If the amounts of O and N in the alloy are large, the degree of vacuum in the deposition atmosphere will deteriorate when the alloy is used for vapor deposition, and good vapor deposition will not be possible, making it impossible to obtain a magnetic thin film with high characteristics. For this reason, the 0 content in the alloy is less than 30 ppm, preferably 10 ppm.
m or less, N content is 30 ppm or less, preferably 10 p
pm or less.

In the present invention, it is not a particular problem that impurities such as St, Mn, P, and S are unavoidably contained in the alloy. It is better to reduce other impurities in it as much as possible, for example, the Si content is 0.1% or less, the Mn content is 0.05% or less, the P content is 50ppm or less, and the S content is 10ppm or less. is preferable.

Such a Ni-Fe-based alloy for vapor deposition of the present invention can be manufactured, for example, according to the method described below.

That is, first, Ni and Fe for alloying.

A1. If necessary, a Ti metal or alloy material is heated in a container whose inner surface is made of a CaO-based refractory material in a non-oxidizing atmosphere such as vacuum or an inert gas such as argon. Alternatively, a molten alloy having a desired composition is obtained by heating and melting using a low frequency induction heating method or the like.

In the present invention, Ca constituting the inner surface of the container used
Examples of O-based refractory materials include calcia (Cab), larnite (stabilized 2CaO-3iO2), and melwinite (3C
aO-Mg0・2Si02), anorsite (CaO・
Examples include Aj2203 .2SiO2) and CaO-enriched dolomite, with fused calcia being particularly preferred.

Such calcia furnace material has a CaO content of 40
% or more, especially 60% or more is preferable.

CaO has a high melting point and is extremely stable at high temperatures, making it possible to obtain a highly clean molten metal without producing metal oxides and contaminating the molten metal with impurities during melting.

In particular, when a container whose inner surface is made of a CaO-based refractory material with a high CaO content is used, refining effects such as removal of ol, removal of S1, and removal of inclusions are also achieved, which is extremely advantageous.

Moreover, since Aj2 or Aλ and Ti are present in the molten metal, O1 removal and S removal in the molten metal occur, and along with this, N removal also occurs. Furthermore, Ca is leached into the molten metal due to the reaction between CaO and An of the furnace wall material. That is, An reacts with O in the molten metal, CaO on the furnace wall, and S in the molten metal to form CaO+S-CaS+0, and reacts with the generated O to form 2AJ2+3O-AJ2203, producing AJ2203. Also, A and 2 in the molten metal react with CaO on the furnace wall to form 2AJ2+3CaO-AJ1203 +3Ca (g)
This also generates Al2O3.

(In this case, the generated Ca becomes a gas and escapes from the system, but a portion remains in the alloy and satisfies the Ca content of the alloy of the present invention.) reacts with CaO of 3
CaO-AJ220s or 12CaO-7AJ220g
An active layer of is formed on the furnace wall surface.

Al2O5+3CaO-*3CaO-AI12037A
fL 203 +1 2CaO-+1 2CaOH7
AjZ 20s This 12CaO+ 7Ai203 and 3CaO・A I
t203, especially 3CaO.Al2O2, has a high ability to remove S from the molten metal, and S removal progresses well.

In this way, active 3CaO・AfL20s and 12Ca generated by de0 by An and by the reducing action of A1.
S removal is performed by OI 7Aj220s and CaO.

In addition, when the refractory material is melted using a CaO-MgO-based container, Mg is also eluted along with Ca, and metallic Mg remains in the molten metal, and like Ca, it plays a getter action during vapor deposition. , complements its effect and makes it even more powerful.

That is, MgO on the furnace wall becomes 3Mg0+CaO+2Au → CaO・Afa O3+3Mg (g),
A portion of the +14g produced remains in the alloy.

Further, N in the molten metal is removed from the molten metal due to evaporation (boiling) of Ca etc. generated by the above-mentioned reaction between AfL and CaO, and the amount of N in the molten metal is also reduced.

When Ti is added, it complements the effect of AfL and further increases Al
De-0, de-S1 and de-N are performed in the same manner as in 1.

Therefore, by carrying out melting in a container whose inner surface is made of a CaO-based refractory material, the low-0, low-N content N
i-Fe-based alloys can be easily obtained.

By the way, in the present invention, when melting is performed in a container whose inner surface is made of a CaO-based refractory material, Al or A
AfL or A1 and T after cooling and solidifying l1 and Ti
It is added so that the residual amount of i is within the range of the present invention, that is, AJ of 21% or less, AfLt% or less, and Ti of 1% or less.
and MgO (MgO content 60 to 15%).
By adding n and Ti, not only Ca but also Mg is added to the molten metal.
The elution of Ca%Mg in the resulting alloy can be easily brought within the range of the present invention, that is, 300 ppm or less.

The molten alloy thus obtained is cast in a non-oxidizing atmosphere according to a conventional method.

According to this method, Ni35-85%, AJ21
% or less, optionally further Ti 1% or less, Ca and/or Mg 300 ppm or less, 030 ppm or less, NN
The Ni-Fe-based alloy for vapor deposition of the present invention containing 30 pp or less and the balance being substantially Fe can be produced very easily.

[Function] Since the Ni-Fe-based alloy for vapor deposition of the present invention has a low content of O and N, a magnetic thin film with high characteristics can be obtained.

Further, A contained in the Ni-Fe-based alloy for vapor deposition of the present invention
l1, Ti, and Cas Mg are 4Aj2+302→2A in a vapor deposition atmosphere such as vacuum vapor deposition or sputtering.
u203 2Aft+N2→2A, IZN 2 Ca + 02 = 2 Ca 03 Ca +
N 2-* Reacts like Ca 3 N 2 and exhibits a so-called getter action that lowers the gas components in the atmosphere.

Similarly, Ti and Mg each complement the action of A11Ca as shown in the following formula, and exhibit good getter action.

Ti+02=TiO2 Ti+02=TiO2 2M g + 02→2Mg0 3Mg0+N2→Mgs N2 Therefore, the stability and formation speed of thin film formation during vapor deposition are improved, and the obtained thin film has high purity and greatly improved magnetic properties, resulting in high It is possible to manufacture characteristic thin films with high production efficiency.

[Example] Examples will be described below.

Example 1 A Ni-Fe-based alloy having the composition shown in Table 1 was used as a material for vapor deposition, and a sputtering device with a diameter of 10
The R film was formed three times each on a cm glass substrate. Note that the substrate heating temperature was 150°C.

Sputtering equipment specifications Magnetron type high frequency sputtering equipment Maximum ratio IKW Ultimate vacuum: 10-'torr Target dimensions: 1 dimension: 100 mutsumi ai 3 mm (t) By changing the sputtering power, argon gas pressure, and sputtering time,
The results of examining the thickness of the thin film formed using each vapor deposition material are shown in FIGS. 1 to 3, respectively.

From FIGS. 1 to 3, it is recognized that the Ni-Fe-based alloy for vapor deposition of the present invention has little variation from batch to batch, is homogeneous, and has high film forming efficiency.

Example 2 Using the sputtering equipment and substrate used in Example 1,
High magnetic permeability thin films were formed using the vapor deposition alloys No. 1, No. 2, No. 3 in Table 1 by forming thin films with a thickness of 3 μm three times each while changing the Ar pressure or substrate heating temperature. Created. Note that the sputtering voltage was set to sow.

The thin film coercivity Hc of the obtained high magnetic permeability material was investigated, and the relationship with substrate heating temperature or Ar pressure is shown in FIGS. 4 and 5, respectively.

From FIG. 4 and FIG. 5, it is recognized that according to the Ni--Fe based alloy for vapor deposition of the present invention, a magnetic material having extremely low coercivity and high magnetic permeability can be stably obtained without variation. In addition, it is possible to omit processes such as substrate heating that require a lot of production time, which is extremely advantageous industrially.

Example 3 In Example 2, the substrate heating temperature was 200°C and the Ar pressure was 4x.
Regarding the high magnetic permeability material obtained at lO-2torr,
Table 2 shows the results of examining its magnetic properties.

Table 2 From Table 2, it is recognized that the high magnetic permeability material obtained from the Ni--Fe based alloy for vapor deposition of the present invention has excellent hysteresis characteristics, high magnetic permeability, and extremely high characteristics.

[Effects of the Invention] As detailed above, the Ni-Fe-based alloy for vapor deposition of the present invention has a low content of 0, N, and also has a getter action of Aλ or AfL and Ti and Ca and/or Mg, so that it can be easily vaporized. Gas components in the atmosphere are significantly reduced.

Therefore, the stability and speed of film formation by vapor deposition are improved, and the obtained thin film has high purity and extremely excellent magnetic properties.

Therefore, according to the N1-Fe-based alloy for vapor deposition of the present invention,
High-performance thin films can be obtained with high efficiency, and the Ni-Fe-based alloy for vapor deposition of the present invention is extremely useful as a vapor deposition material for producing thin films of high magnetic permeability materials.

2 is a graph showing the relationship between sputtering voltage, argon pressure, sputtering time, and the resulting film thickness, respectively. Fourth
5 and 5 are graphs showing the results obtained in Example 2, and show the relationships between substrate heating temperature, argon pressure, and coercivity of the magnetic recording material, respectively.

Representative Patent Attorney Tsuyoshi Shigeno Figure 4 Base heating temperature (’C) Ar pressure (×1σ2torr)

Claims (2)

[Claims] (1) Ni 35-85% by weight, Al 1% by weight or less, Ca
and/or Mg 300ppm or less, O 30ppm or less,
A Ni-Fe-based alloy for vapor deposition, characterized in that it contains 30 ppm or less of N, and the remainder is substantially Fe. (2) Ni 35-85% by weight, Al 1% by weight or less, Ti
1% by weight or less, Ca and/or Mg 300ppm or less,
Ni-Fe for vapor deposition, characterized in that it contains 30 ppm or less of O, 30 ppm or less of N, and the remainder is substantially Fe.
Base alloy.