JPH0356299B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a Co-Ni based alloy for vapor deposition, and particularly to a Co-Ni based alloy for vapor deposition suitable for manufacturing thin films used as magnetic recording materials. [Prior Art] A magnetic recording material in which a magnetic alloy thin film is formed on a non-magnetic substrate is well known. Vapor deposition methods such as sputtering, vacuum evaporation, and ion plating 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 a ferromagnetic alloy that forms a magnetic alloy thin film,
Iron alloys, nickel alloys, cobalt alloys, etc. have been conventionally used. Among cobalt alloys, Co--Ni based alloys have been studied in various ways as in-plane 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 in which a magnetic material powder such as metal or metal oxide is kneaded with a synthetic resin binder and coated on the tape base material, a magnetic metal thin film is formed on the tape base material. Magnetic tape has been proposed to enable high-density recording. Electroless plating methods can also be used to form this magnetic metal thin film, but vacuum deposition, ion plating, etc. A vapor deposition method including the following is preferably used. Among these, tapes with a magnetic vapor deposition film of Co-Ni metal with a composition of 80% Co-20% Ni have excellent Hc (coercive force) and Br (residual magnetic flux density) properties, and are suitable as high-density recording tapes. is expected to be used widely. [Problems to be solved by the invention] After conducting various studies on conventionally used magnetic alloys, we found that oxygen, nitrogen, sulfur, carbon,
In addition, inclusions such as metal oxides were included in a relatively large amount, which was found to have 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 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. Ni5 to 30% by weight, Al 1% by weight or less Ca and/or
A Co-Ni based alloy for deposition, containing 300ppm or less of Mg, 30ppm or less of O, and 30ppm or less of N, with the remainder being substantially Co, 5 to 30% by weight of Ni, 1% or less of Al, 1% or less of Ti, Ca and/or contains 300ppm or less of Mg, 30ppm or less of O, and 30ppm or less of N, with the remainder being substantially Co.
Co-Ni based alloy for deposition, characterized by: 5 to 30% by weight of Ni, 25% by weight or less of Cr, 1% by weight of Al
Below, Ca and/or Mg300ppm or less, O30ppm
Contains 30ppm or less of N, with the remainder being substantially
A Co-Ni based alloy for vapor deposition characterized by being Co, and 5 to 30% by weight of Ni, 25% by weight or less of Cr, and 1% by weight of Al.
Below, Ti 1% by weight or less, Ca and/or Mg 300ppm
Hereinafter, a deposition material containing 30 ppm or less of O, 30 ppm or less of N, and the remainder being substantially Co.
Co-Ni based alloy. That is, the present inventors aimed to solve the problem caused by impurities in the deposition alloy and obtain a high-characteristic magnetic thin film.
As a result of extensive research, we found that a specific amount of Ca and/or Mg and Al or
By containing Al and Ti, an alloy with low impurity content can be obtained, and the getter action of Ca and/or foil Mg and Al and/or Ti also reduces gas components in the deposition atmosphere. The inventors have discovered that it is possible to obtain a magnetic thin film with extremely high purity and high properties, and have completed the present invention. Hereinafter, the present invention will be explained in detail. In addition, in this specification, "%" is "weight%"
It represents. 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 plating, etc., and is used for manufacturing magnetic thin films, etc. The composition is as follows. It is. Ni: 5-30% Cr: None (first and second invention) or 25%
Below (third and fourth inventions) Co: balance Al: 1% or less Ti: not contained (first and third inventions) or 1%
Below (Second and Fourth Inventions) Ca and/or Mg: 300 ppm or less O: 30 ppm or less N: 30 ppm The reasons for limiting the alloy composition of the present invention will be explained below. In the Co-Ni base alloy for vapor deposition of the present invention, if Ni is too small, the coercive force Hc will be too high and the overwrite characteristics will deteriorate; if it is too large, the coercive force Hc and residual magnetic flux density Bs will become low, resulting in hysteresis characteristics. It also gets worse. For this reason, Ni is set at 5 to 30%.
By setting the preferable Ni content to 15 to 25%, particularly 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. Al and Ti are used when melting alloys, such as Ca and Ti.
Together with Mg, it acts to clean the alloy, and also has a getter effect to capture gas components in the deposition atmosphere. However, the amounts of Al and Ti are too large,
It is undesirable if the amount affects the alloy properties, so in the present invention, each is set at 1% or less. Naturally, if the amounts of Al and Ti are too small, sufficient effects of the above-mentioned cleaning action and getter action cannot be obtained. In the present invention, Al0.01~0.5%, or Al0.01~0.5%
0.5% and Ti0.5% or less, more preferably Al0.05~
It is desirable to set the content to 0.2%, or 0.05 to 0.2% for Al and 0.2% for Ti. Note that Al or Ti is a solid solution.
The effect of the present invention is achieved by being present in the alloy in the form of Al or solid solution Ti.
It is important that Al or Ti exists in a solid solution state. As mentioned above, Ca and Mg work together with Al and/or Ti to clean the alloy and also have a getter action. If the content of Ca and Mg is too high, 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 Mg
Even if the content of Ca and Mg is too small, sufficient cleaning action and scavenging action by Ca and Mg will not occur. For this reason, the Ca and Mg contents should be 5 to 5, respectively.
A range of 100 ppm, preferably 10 to 50 ppm each is preferred. Note that Ca is CaO or CaO−
The effects of the present invention cannot be achieved in the form of Al ₂ O ₃ , and similarly, the effects of the present invention cannot be achieved with Mg in the form of MgO. It is important that it is Mg. If the amounts of O and N in the alloy are large, the degree of vacuum in the vapor 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. Therefore, the O content in the alloy is 30 ppm or less, preferably 20 ppm or less, and the N content is 30 ppm or less, preferably 20 ppm or less. In the present invention, it is not a particular problem that impurities such as Si, Mn, P, and S are unavoidably contained in the alloy. Other impurities in the material are preferably reduced as much as possible; for example, the Si content is preferably 0.01% or less, the Mn content is 0.005% or less, the P content is 50ppm or less, and the S content is 10ppm or less. Such a Co-Ni based alloy for vapor deposition of the present invention,
For example, it can be manufactured according to the method described below. That is, first, metals or alloy materials such as Co, Ni, optionally Cr, Al, and optionally Ti for alloying are placed in a container whose inner surface is made of a CaO-based refractory material, and heated under vacuum or argon gas. A molten alloy having a desired composition is obtained by heating and melting in a non-oxidizing atmosphere such as an inert gas atmosphere using a conventional method such as high frequency or low frequency induction heating. In the present invention, the CaO refractory material constituting the inner surface of the container used is calcia (CaO),
Larnite (stabilized 2CaO・SiO ₂ ), melwinite (3CaO・MgO・2SiO ₂ ), anorsite (CaO・Al ₂ O ₃・2SiO ₂ ), and CaO-enriched dolomite are included, but in particular, fused calcia is suitable. Such calcia furnace material preferably has a CaO content of 40% or more, particularly 60% or more. CaO has a high melting point and is extremely stable at high temperatures. During melting, CaO does not generate metal oxidation and contaminate the molten metal with impurities, making it possible to obtain a highly clean molten metal. In particular, when using a container whose inner surface is made of a CaO-based refractory material with a high CaO content,
It also has a refining effect such as removal of inclusions, which is extremely advantageous. Moreover, since Al or Al and Ti are present in the molten metal, O and S are removed from the molten metal, and along with this, N is also removed. In addition, the furnace wall material CaO and
Ca also elutes into the molten metal due to the reaction with Al.
That is, Al reacts with O in the molten metal, CaO on the furnace wall, and S in the molten metal to form CaO+S→CaS+O, and reacts with the generated O to form 2Al+3O→Al ₂ O ₃ , producing Al ₂ O ₃ . . Furthermore, Al in the molten metal reacts with CaO on the furnace wall to form 2Al+3CaO→Al ₂ O ₃ +3Ca(g), and this also produces Al ₂ O ₃ . (In this case, the generated Ca becomes a gas and escapes from the system, but some of it remains in the alloy and
Satisfy Ca content. ) Al ₂ O ₃ reacts with CaO in the furnace wall as shown in the following equation,
An active layer of 3CaO.Al ₂ O ₃ or 12CaO.7Al ₂ O ₃ is formed on the furnace wall surface. Al ₂ O ₃ +3CaO→3CaO・Al ₂ O ₃ 7Al ₂ O ₃ +12CaO→12CaO・7Al ₂ O _3This 12CaO・7Al ₂ O ₃ and 3CaO・Al ₂ O ₃ , especially
3CaO.Al ₂ O ₃ has a high ability to remove S from molten metal, and S removal progresses well. In this way, active 3CaO・Al ₂ O ₃ generated by O removal by Al and the reduction action of Al,
S removal is performed using 12CaO・7Al ₂ O ₃ 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, causing a gettuding effect during vapor deposition like Ca. play, complement the effect, and make it even more powerful. That is, the MgO in the furnace wall becomes 3MgO+CaO+2Al→CaO.Al ₂ O ₃ +3Mg(g), and a part 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 Al and CaO as described above, and the amount of N in the molten metal is also reduced. When Ti is added, it complements the action of Al and further
It removes O, S, and N by the same action as Al. Therefore, by carrying out melting in a container whose inner surface is made of a CaO-based refractory material, the Co--Ni based alloy of the present invention having a low O and low N content can be easily obtained. By the way, in the present invention, Al
Or Al or Al after cooling and solidifying Al and Ti
CaO and Ti are added so that the residual amount is within the range of the present invention, that is, Al1% or less or Al1% and Ti1% or less. ~15%) of calcia-based refractory,
Ca in the molten metal is increased by adding Al or Al and Ti.
In addition, the elution of Mg was also observed, making it easy to control the Ca and Mg contents in the resulting alloy within the range of the present invention, i.e.
It can be 300ppm or less. The molten alloy thus obtained is cast in a non-oxidizing atmosphere according to a conventional method. According to such a method, Ni5-30%, sometimes Cr25% or less, Al1% or less, sometimes Ti1%
Below, Ca and/or Mg300ppm or less, O30ppm
Contains 30ppm or less of N, with the remainder being substantially
The Co-Ni based alloy for vapor deposition of the present invention, which is Co, can be produced very easily. [Function] Since the Co-Ni-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. In addition, Al and/or Ti, Ca contained in the Co-Ni-based alloy for vapor deposition of the present invention is 4Al+3O ₂ →2Al ₂ O ₃ 2Al+N ₂ →2AlN 2Ca+O ₂ in a vapor deposition atmosphere such as vacuum evaporation or sputtering. →2CaO 3Ca+N ₂ →Ca ₃ N ₂ It reacts as follows, producing a so-called getter effect that lowers the gas components in the atmosphere. Similarly, Ti and Mg also complement the effects of Al and Ca, respectively, as shown in the following equations, and exhibit good getter effects. Ti＋O ₂ →TiO ₂ Ti＋N ₂ →TiN ₂ 2Mg＋O ₂ →2MgO 3MgO＋N ₂ →Mg ₃ N _2This improves the stability and formation speed of thin film formation during vapor deposition, and the resulting thin film has high purity and significantly improved magnetic properties. This makes it possible to manufacture high-performance thin films with high production efficiency. [Example] Examples will be described below. Example 1 A thin film was formed on a glass substrate having a diameter of 10 cm using a Co-Ni based alloy having the composition shown in Table 1 as a deposition material using a sputtering apparatus having the following specifications.
Note that the substrate heating temperature was 80°C. Sputtering equipment specifications High frequency magnetron type high speed sputtering equipment Maximum output: 1KW Ultimate vacuum: 10 ^-7 torr Target dimensions: 100mm (φ) x 3mm (t)

【table】

[Table] Figure 1 shows the results of examining the thickness of thin films formed with each deposition material while changing the argon gas pressure. From FIG. 1, the Co-Ni base alloy for vapor deposition of the present invention is
It is recognized that the stability of the thin film and the film formation efficiency are high. Example 2 Using the sputtering apparatus and substrate used in Example 1, magnetic recording materials were manufactured by forming thin films of 3 μm thick with the vapor deposited alloys Nos. 1 to 6 in Table 1, respectively. Note that the sputtering voltage was 500W. The coercive force Hc and residual magnetic flux density Br of the obtained magnetic recording material were investigated using a thin film vibration type magnetometer, and the results are shown in Table 2. Table 2 shows that the Co--Ni based alloy for deposition of the present invention provides a magnetic recording material with extremely high coercive force and residual magnetic flux density.

[Table] Example 3 Table 3 shows the gas analysis results of Co--Ni thin films No. 1, 3, and 5 obtained in Example 2.

[Table] Table 3 shows that in the alloy of the present invention, no increase in gas components was observed due to sputtering, whereas in the alloy of the present invention, no increase in gas components was observed due to sputtering.
A significant increase was observed in Comparative Example No. 5, demonstrating the effect of the alloy target of the present invention. [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 and N, and due to the gettering effect of Al or Al and Ti with Ca and Mg, it is difficult to form a vapor deposition atmosphere. The gas components inside 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-based alloy for vapor deposition of the present invention can be used for vapor deposition for manufacturing thin films of magneto-optical recording materials. Extremely useful as a material.

[Brief explanation of drawings]

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

Claims (1)

[Scope of Claims] 1 Co-for deposition, characterized in that it contains 5 to 30% by weight of Ni, 1% by weight or less of Al, Ca and/or 300ppm or less of Mg, 30ppm or less of O, and 30ppm or less of N, with the remainder being substantially Co. Ni-based alloy. 2 Ni 5-30% by weight, Al 1% by weight or less, Ti 1% by weight
Below, Ca and/or Mg300ppm or less, O30ppm
Contains 30ppm or less of N, with the remainder being substantially
A Co-Ni-based alloy for deposition, characterized by being Co. 3 Ni 5 to 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 vapor deposition characterized by containing 30ppm or less of O, 30ppm or less of N, and the remainder being 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
A Co-Ni-based alloy for deposition, characterized in that it contains 300 ppm or less of Mg, 30 ppm or less of O, and 30 ppm or less of N, with the remainder being substantially Co.