JPS6396260A - Co-ni alloy for vapor deposition - Google Patents

Abstract

PURPOSE:To obtain a Co-Ni alloy for vapor deposition having a low impurity content and enabling stable and efficient formation of a magnetic thin film having superior characteristics, by specifying a compsn. consisting of Ni, Al, Ca, Mg, O, N and Co. CONSTITUTION:This Co-Ni alloy for vapor deposition consists of 5-30wt% Ni, <=1wt% Al, <=300ppm Ca and/or Mg, <=30ppm O, <=30ppm N and the balance essentially Co or further contains <=1wt% Ti and/or <=25wt% Cr. The alloy is suitable for use in the production of a thin film having superior magnetic characteristics and used as a magnetic recording material. Co, Ni, and Al to be alloyed are put in a vessel lined with a CaO-base refractory, metals such as Ti and/or Cr or an alloying material is further added as required and they are melted by high frequency induction heating or other heating method in a nonoxidizing atmosphere to obtain the Co-Ni alloy.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a Co-Ni based alloy for deposition, and in particular to a Co-Ni based alloy for deposition, which is suitable for manufacturing thin films used as magnetic recording materials.
It relates to a Ni-based alloy.

[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. It is.

The ferromagnetic alloys that form the magnetic alloy thin film include iron alloys,
Nickel alloys, cobalt alloys, etc. have been used conventionally. Among cobalt alloys, Co--Ni based alloys have been studied in various ways as longitudinal magnetic recording materials because they are easy to obtain with high coercive force and high residual magnetic flux density.

In other words, instead of the conventional magnetic recording tape, which is made by coating a tape base material with magnetic material powder such as metal or metal oxide mixed with a synthetic resin binder, a thin magnetic metal film is coated on the tape base material. A magnetic tape capable of high-density recording has been proposed. Electroless plating methods can also be used to form this magnetic metal thin film, but depending on the base treatment, homogeneity, adhesion, or formation speed of the magnetic metal thin film, vacuum evaporation, ion blating, etc. A vapor deposition method including the following is preferably used. Among them, 80%C
o-C with a composition of 20% Ni.

- The tape on which the magnetic evaporated film of Ni-based metal is formed is Hc (
It also has excellent coercive force) and Br (residual magnetic flux density) characteristics, and is expected to be widely used as a high-density recording tape.

[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 was recognized that this would have a significant negative effect on the magnetic properties of the resulting thin film.

[Means for Solving the Problems] In view of the above-mentioned conventional situation, the present invention aims to provide a Co-Ni-based alloy for deposition, which can stably and efficiently obtain a high-performance magnetic thin film with a low impurity content. Ni 5-30% by weight, Al 1% by weight or less Ca and/or MMg 300pp or less, 030ppm or less, NN30p
A Co-Ni-based alloy for deposition, characterized in that it contains p or less and the remainder is substantially Co, 5 to 30% by weight of Ni, 1% by weight or less of A°C, 1% by weight of Ti
Below, Ca and/or MMg 300pp or less, 030p
pm or less, NN30pp or less, and the remainder is substantially Co, a Co-Ni-based alloy for deposition, characterized in that Ni5-30% by weight, Cr25% by weight or less, AfL 1% by weight or less, Ca and/or MMg300pp or less, 03
A Co-Ni-based alloy for deposition, characterized in that it contains 0 ppm or less, NN 30 pp or less, and the remainder is substantially Co, and 5 to 30 wt% Ni, 25 wt% or less Cr, 1 wt% or less AIL, and 1 wt% Ti. Below, Ca and/or MMg3
00 ppm or less, 0.030 ppm or less, NN30 ppm or less, and the remainder is substantially Co.

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 inventor has found that a specific amount of Ca and By containing / or Mg, An or A4, and Ti, an alloy with low impurity content can be obtained,
Moreover, it was discovered that the gettering effect of Ca and/or Mg and A1 and/or Ti can also reduce the gas components in the atmosphere surrounding the evaporation process, making it possible to obtain a magnetic thin film with extremely high purity and high characteristics. Completed.

Hereinafter, the present invention will be explained in detail.

In addition, in this specification, "r%" represents "wt%".

The Co-Ni-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. It is.

Ni: 5 to 30% Cr: Not contained (first and second inventions) or 25% or less (third and fourth inventions) Co: Balance All: 1% or less Ti: Not contained (first and second inventions) third invention) or 1% or less (
2nd and 4th invention) Ca and/or Mg: 300ppm or less 0:30p
pm or less N +30 ppm The reasons for limiting the alloy composition of the present invention will be explained below.

In the Co-Ni based alloy for vapor deposition of the present invention, if Ni is too small, the coercive force He will be too high and the override characteristics will be poor; if it is too large, the coercive force Hc and the residual magnetic flux density B
s becomes low, and the hysteresis characteristics also deteriorate. For this reason, Ni is set at 5 to 30%. The preferred Ni content is 15
By setting the content to 25%, especially 18 to 22%, extremely excellent properties can be obtained.

Cr acts to improve magnetic properties and corrosion resistance. However, if its content is too large, it may adversely affect the magnetic properties, so in the present invention, the content of Cr is set to 25% or less, particularly 15% or less.

A℃ and Ti are used for Ca, Mg, and Ti 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, Aλ,
It is undesirable for the amount of Ti to be too large and to affect the alloy properties. Therefore, in the present invention, each amount is set to 1% or less. Naturally, AJ2,
If the amount of Ti is too small, sufficient effects of the above-mentioned cleaning and gettering effects cannot be obtained. In the present invention, Ag0.01 to 0.5% or AJ
20.01-0.5% and Ti005% or less, more preferably AJ20.05-0.2%, or AJlo
, 05 to 0.2% and Ti 0.2% or less. Note that AJl or Ti is solid solution Al or solid solution Ti.
Since the effects of the present invention are achieved by being present in the alloy in this form, it is important that Al or Ti exists in a solid solution state.

As mentioned above, Ca and Mg work together with An and/or Ti to clean the alloy, and also have a getter action.

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, if the content of Ca and/or Mg is too small, sufficient cleaning and gettering effects by Ca and Mg will not be exhibited. For this reason, the Ca and Mg contents are each in the range of 5 to 1100 pp, preferably each in the range of 10 to 5 pp.
It is preferable to set it to 0 ppm. Note that Ca is CaO or Ca0-Aj! The effect of the present invention can be achieved in the form of 203. Similarly, the effect of the present invention cannot be achieved in the form of MgO, so the existence forms of Ca and Mg in the alloy are metallic Ca and metallic Mg. This is very important.

If the amounts of O and H in the alloy are large, the degree of vacuum in the deposition atmosphere deteriorates when the alloy is used for vapor deposition, and good vapor deposition cannot be performed, making it impossible to obtain a magnetic thin film with high characteristics. Therefore, the 0 content in the alloy is less than 30 ppm, preferably 20 ppm.
m or less, N content is 30 ppm or less, preferably 20 p
pm or less.

In the present invention, it is not a particular problem that impurities such as Si, Mn% PlS, etc. are unavoidably contained in the alloy. It is better to reduce other impurities as much as possible, for example, the St content is 0.01% or less, the Mn content is 0.005% or less, the P content is 50 ppm or less,
The S content is preferably 10 ppm or less.

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

That is, first, Co1Ni1 optionally C
r%A℃, and if necessary, a metal or alloy material such as Ti is normally heated in a non-oxidizing atmosphere such as vacuum or an inert gas atmosphere such as argon in a container whose inner surface is made of a CaO-based refractory material. A molten alloy having a desired composition is obtained by heating and melting using a method such as a high frequency or low frequency induction heating method.

In the present invention, Ca constituting the inner surface of the container used
Examples of O-grade refractory materials include calcia (Cab), larnite (stabilized 2CaO・5io2), and melwinite (3C
aO-Mg0・2SiO2), anorsite (CaO・
Al2O*.2SiO2) and CaO-enriched dolomite may be mentioned, and fused calcia is 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 zero removal, S removal, inclusion removal, etc. are also achieved, which is extremely advantageous.

Furthermore, since AJl or Aj2 and Ti are present in the molten metal, O0 and S are removed from the molten metal, and along with this, N is also removed. Furthermore, Ca is leached into the molten metal due to the reaction between CaO and Al in the furnace wall material. That is, AjZ reacts with O in the molten metal, CaO on the furnace wall, and S in the molten metal to form Ca O+ S → Ca S + 0, and reacts with the generated O to form 2Al+30→AfL203, producing AJl203. Further, A4 in the molten metal reacts with CaO on the furnace wall to form 2Al+3CaO''Al2o3+3Ca (g), which also produces A4203.

(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.) Al22 oi is calculated as follows: Reacts with CaO on the wall,
3CaO・Al203 or 12Ca0・7Al203
An active layer of is formed on the furnace wall surface.

AJl203 +3CaO-+3CaO-A! 1203
7A fl 203 +1 2CaO-+1 2Ca
OH7Aj2203 This 12CaO+ 7AI1202 and 3CaO-A
lt 203 , especially 3CaO.Al2o3, has a high ability to remove S from the molten metal, and S removal progresses well.

In this way, active 3CaO・Al2O3,12Ca0 is deoxidized by Al and generated by the reducing action of Al.
・S removal is performed using 7AJ2203 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, the MgO on the furnace wall is 3Mg0+CaO+2AJl! - CaO-Aft 203 +3Mg (g),
A portion of the generated Mg 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 reaction between Aj2 and CaO, and the amount of N in the molten metal is also reduced.

When Ti is added, it complements the action of AjZ and further increases An
0, S, and N are removed by the same action.

Therefore, by performing melting in a container whose inner surface is made of a CaO-based refractory material, the low 0 and low N content carbon of the present invention can be produced.
An o-Ni-based alloy can be easily obtained.

By the way, in the present invention, when melting is performed in a container whose inner surface is made of CaO-based refractory material, Al or Af
After cooling and solidifying Al and Ti, the residual amount of Al or 8λ and Ti is within the range of the present invention, that is, Al 1% or less or Af
It is added so that the L content is 1% or less and the Ti content is 1% or less.
By making the calcia-based refractory of KO (MgO content 60-15%),
By adding fl and Ti, not only Ca but also M in the molten metal
The elution of Ca and Mg in the obtained 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 such a method, Ni 5-30%, Cr 25% or less, Al 1% or less, Ti 1% or less, Ca and/or MMg 300pp or less, 030pp
m or less, NN30pp or less, and the remainder is substantially C.
The Co-Ni-based alloy for vapor deposition of the present invention which is 0 can be produced very easily.

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

Further, A contained in the Co-Ni-based alloy for vapor deposition of the present invention
°C and/or TI% Ca is 4Al+302-2Al in a vapor deposition atmosphere such as vacuum vapor deposition or sputtering.
203 2Afl+N2→2AlN 2Ca + 02 = 2 Ca 03Ca+N
It reacts like 2 = Ca 3 N2 and exhibits a so-called getter action that lowers the gas component in the atmosphere.

Similarly, Ti and Mg are each Afl.

A good getter effect is achieved by complementing the effect of Ca as shown in the formula below.

Ti+02-Ti02 Ti+N2→TiN2 2 M g + 02 = 2 M g O3MgO+
N2→Mg3N2 Therefore, the stability and formation speed of thin film formation during vapor deposition are improved, and the resulting thin film has high purity and greatly improved magnetic properties, making it possible to manufacture high-performance thin films with high production efficiency. do.

[Example] Examples will be described below.

Example 1 A Co-Ni based alloy having the composition shown in Table 1 was used as a deposition material, and a sputtering device with a diameter of 10
A thin film was formed on a glass base embankment with a thickness of 1.5 cm. Note that the substrate heating temperature was 80°C.

Sputtering equipment specifications High-frequency magnetron type high-speed sputtering equipment Maximum circular crab IKW Ultimate vacuum: 10-'torr Target dimensions: 100 mm (φ) x: lnm (t) Thin films formed from each deposition material by changing the argon gas pressure The results of examining the film thickness are shown in Figure 1.

From FIG. 1, it is recognized that the Co--Ni based alloy for vapor deposition of the present invention has high stability in film quality and high film formation efficiency.

Example 2 Using the sputtering equipment and substrate used in Example 1,
For the vapor deposition alloys No. 1 to 6 in Table 1, 3 μm each.
A magnetic recording material was produced by forming a thin film with a thickness of m. Note that the sputtering voltage was 500W.

Coercive force Hc and residual magnetic flux density Br of the obtained magnetic recording material
was investigated using a thin film vibrating magnetometer, and the results are shown in Table 2.

From Table 2, it is recognized that the Co--Ni based alloy for vapor deposition of the present invention provides a magnetic recording material with extremely high coercive force and residual magnetic flux density.

Table 2 Example 3 Table 3 shows the gas analysis results of the No. 1.3.5 Co-Ni film obtained in Example 2.

Table 3 (ppm) From Table 3, it can be seen that in the alloy of the present invention, no increase in gas components was observed due to sputtering, whereas in the comparative example alloy No. 5, a significant increase was observed. The effect is recognized.

[Effects of the Invention] As detailed above, the Co-Ni-based alloy for vapor deposition of the present invention has a low content of O, N, and Afl or AJl.
Also, due to the getter action of Ti and Ca%Mg, the gas components in the vapor deposition 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 Co-Ni based alloy for vapor deposition of the present invention, a thin film with high characteristics can be obtained with high efficiency, and the Co-Ni base alloy for vapor deposition of the present invention can be obtained with high efficiency.
O-Ni-based alloys are extremely useful as deposition materials for producing thin films of magneto-optical recording materials.

[Brief explanation of the drawing]

FIG. 1 is a graph showing the results obtained in Example 1, and shows the relationship between the argon pressure and the obtained film thickness.

Claims (4)

[Claims] (1) Ni 5-30% by weight, Al 1% by weight or less Ca and/or Mg 300ppm or less, O 30ppm or less, N3
A Co-Ni-based alloy for vapor deposition, characterized in that it contains 0 ppm or less, and the remainder is substantially Co. (2) Ni 5-30% by weight, Al 1% by weight or less, Ti1
Weight% or less, Ca and/or Mg 300ppm or less, O
30 ppm or less, N30 ppm or less, and the remainder is substantially Co. (3) Ni 5-30% by weight, Cr 25% by weight or less, Al
1% by weight or less, Ca and/or Mg 300ppm or less,
Co-Ni for deposition, characterized in that it contains 30 ppm or less of O, 30 ppm or less of N, and the remainder is substantially Co.
Base alloy. (4) Ni 5-30% by weight, Cr 25% by weight or less, Al
1% by weight or less, Ti 1% by weight or less, Ca and/or Mg
A Co-Ni-based alloy for vapor deposition, characterized in that it contains 300 ppm or less, 30 ppm or less of O, and 30 ppm or less of N, with the remainder being substantially Co.