JPH0364586B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a Ni-Fe based alloy for deposition, and in particular to a Ni-Fe base alloy for deposition, which is suitable for manufacturing thin films that are used as base materials for head materials and magnetic recording materials, taking advantage of its high magnetic permeability. Regarding Fe-based alloys. [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 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. It is. As a ferromagnetic alloy that forms a magnetic alloy thin film,
Nickel alloys, cobalt alloys, iron alloys, etc. have been used conventionally, but among these, Ni-Fe
Various base alloys are in practical use because they have high magnetic permeability. For example, 35 to 90% Ni in Ni-Fe system
The alloy is called permalloy because it has high magnetic permeability, and it is especially made of 70-80% Ni.
The alloy is called Permalloy A (PA) and has a large initial magnetic permeability μo and maximum magnetic permeability μm in a weak magnetic field. 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 oxygen, nitrogen, sulfur, carbon,
It was found that a relatively large amount of other inclusions such as metal oxides were included, and this had 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 aims to provide a Ni-Fe-based alloy for deposition, which can stably and efficiently produce a high-performance magnetic thin film with a low impurity content. Ni35 to 85% by weight, Al 1% or less by weight, Ca and/or
or Mg300ppm or less, and as impurities
Ni- for vapor deposition characterized by containing 30ppm or less of O and 30ppm or less of N, with the remainder being substantially Fe.
Fe-based alloy, Ni 35-85% by weight, Al 1% by weight or less, Ti 1% by weight
Below, Ca and/or Mg 300ppm or less, and
The gist of the present invention is a Ni-Fe-based alloy for vapor deposition, which contains impurities of 30 ppm or less of O and 30 ppm of N, with the remainder being substantially Fe. 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 Mg and Al and/or Ti can also reduce gas components in the deposition atmosphere, making it extremely The present invention was completed by discovering that it is possible to obtain a magnetic thin film with high purity and high characteristics. Hereinafter, the present invention will be explained in detail. In addition, in this specification, "%" is "weight%"
It represents. The Ni-Fe-based alloy for deposition of the present invention is used as a material for deposition in vacuum deposition, sputtering, ion plating, etc., and is used for manufacturing magnetic thin films, etc., and its composition is as follows. It is. Ni: 35-85% Fe: Balance Al: 1% or less Ti: None (first invention) or 1% or less (second invention) Ca and/or Mg: 300ppm or less O: 30ppm or less N: 30ppm The reasons for limiting the alloy composition of the present invention will be explained below. In the Ni-Fe base alloy for vapor deposition of the present invention, Ni is
35-85%. This is because extremely high magnetic permeability can be obtained with Ni content in this range.
By setting the preferable Ni content to 70 to 85%, particularly 78.5%, a significantly high magnetic permeability can be obtained. 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 that captures gas components in the deposition atmosphere. However, the amounts of Al and Ti are too large,
It is not preferable 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, Al0.005~0.5%, or Al0.005~0.5%
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
Even if the Mg content is too low, sufficient cleaning and scavenging effects by Ca and Mg will not occur. For this reason, the Ca and Ng contents are each 5 to 5.
A range of 100 ppm, preferably 10 to 50 ppm each is preferred. In addition, Ca is CaO or
The effect of the present invention cannot be achieved in the form of CaO-Al ₂ O ₃ , and similarly, the effect of the present invention cannot be achieved in the form of MgO, so the existence form of Ca and Mg in the alloy is metal Ca. , the weight is Mg metal. If the amount of impurities such as O and N in the alloy is large, the degree of vacuum in the deposition atmosphere may deteriorate when the alloy is used for vapor deposition, or good vapor deposition may not be performed, 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 10 ppm or less, and the N content is 30 ppm or less, preferably 10 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 0.1% 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. Such a Ni-Fe-based alloy for vapor deposition of the present invention is
For example, it can be manufactured according to the method described below. That is, first, Ni, Fe, Al, and optionally Ti metals or alloy materials for alloying are added to the inner surface.
In a container made of CaO refractory material, in a non-oxidizing atmosphere such as vacuum or an inert gas atmosphere such as argon, by heating and melting using a conventional method such as high frequency or low frequency induction heating method. A molten alloy having a desired composition is obtained. In the present invention, the CaO refractory material constituting the inner surface of the container used is calcia (CaO),
Larnite (stabilized 2CaO・BiO ₂ ), melwinite (3CaO・MgO・2BiO ₂ ), anorthite (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 oxides 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 on 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, MgO on 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 refractory material, the low O and low N content Ni-Fe base alloy of the present invention can be easily obtained. By the way, in the present invention, Al
Or Al or Al after cooling and solidifying Al and Ti
It is added so that the remaining amounts of Ti and Ti are within the range of the present invention, that is, Al 1% or less, Al 1% or less, and Ti 1% or less. 60~15%)
By adding Al or Al and Ti, not only Ca but also Mg can be leached into the molten metal, making it easy to control the Ca and Mg contents in the resulting alloy. It can be 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, Ni35~80%, Al1%
Below, if necessary, Ti1% or less, Ca and/or
Mg 300ppm or less and 030ppm as impurities
and N30ppm or less, with the remainder being substantially
The Ni-Fe based alloy for vapor deposition of the present invention, which is 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 impurities such as O and N, a magnetic thin film with high characteristics can be obtained. Moreover, Al, Ti, Ca, and Mg contained in the Ni-Fe-based alloy for vapor deposition of the present invention are 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 at high production rates. [Example] Examples will be described below. Example 1 Using a Ni--Fe based alloy having the composition shown in Table 1 as a material for vapor deposition, thin films were formed three times each on a glass substrate with a diameter of 10 cm using a sputtering apparatus having the following specifications. Note that the substrate heating temperature was 150°C. Sputtering equipment specifications Magnetron type high frequency sputtering equipment Maximum output: 1KW Ultimate vacuum: 10 ^-7 torr Target dimensions: 100mm (φ) x 3mm (t)

[Table] Figures 1 to 3 show the results of examining the thickness of thin films formed with each deposition material while varying the sputtering power, argon gas pressure, and sputtering time. From Fig. 1 to Fig. 3, Ni-Fe for vapor deposition of the present invention is shown.
It is recognized that the base alloy has little variation from batch to batch, is homogeneous, and has a high film formation success rate. Example 2 Using the sputtering equipment and substrate used in Example 1, the evaporation alloys No. 1, No. 2, and No. 3 in Table 1 were used, and the Ar pressure or substrate heating temperature was changed, respectively.
A high magnetic permeability thin film was created by forming a 3 μm thick thin film three times each. Note that the sputtering voltage was 500W. Examining the thin film coercivity Hc of the obtained high permeability material,
The relationship with substrate heating temperature or Ar pressure is
As shown in FIG. From FIG. 4 and FIG. 5, it can be seen that Ni-
It has been found that with Fe-based alloys, magnetic materials with extremely low retention rates and high permeability can be stably obtained without variation. In addition, it is possible to omit steps such as substrate heating that require a lot of production time, which is extremely advantageous industrially. Example 3 Table 2 shows the results of examining the magnetic properties of the high magnetic permeability material obtained in Example 2 at a substrate heating temperature of 200° C. and an Ar pressure of 4×10 ⁻² torr.

[Table] 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 impurities such as O and H, and also has no gettering effect due to Al or Al and Ti and Ca and/or Mg. As a result, gas components in the 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 Ni-Fe-based alloy for vapor deposition of the present invention, a thin film with high characteristics can be obtained with high efficiency, and the Ni-Fe-based alloy for vapor deposition of the present invention can be used for vapor deposition for manufacturing thin films of high magnetic permeability materials. Extremely useful as a material.

[Brief explanation of drawings]

Each of FIGS. 1 to 3 is a graph showing the results obtained in Example 1, and each shows the relationship between sputtering voltage, argon pressure, sputtering time, and the resulting film thickness. FIGS. 4 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.

Claims (1)

[Claims] 1. Contains 35 to 85% by weight of Ni, 1% by weight or less of Al, 300ppm or less of Ca and/or Mg, and 30ppm or less of O and 30ppm or less of N as impurities, with the balance being substantially Fe. Ni for vapor deposition
-Fe-based alloy. 2 35 to 85% by weight of Ni, 1% by weight or less of Al, 1% by weight or less of Ti, 300ppm or less of Ca and/or Mg, and
A Ni-Fe-based alloy for vapor deposition, characterized in that it contains 30 ppm or less of O and 30 ppm or less of N as impurities, with the remainder being substantially Fe.