Method of manufacturing perpendicular type magnetic recording member

A perpendicular type magnetic recording member comprising a perpendicular-incidence magnetic film on a substrate, the perpendicular-incidence magnetic film comprising a magnetic metal and oxygen, the magnetic metal being selected from the group consisting of ferro-magnetic alloys, alloys thereof and combinations thereof; and a method of manufacturing the perpendicular type recording member by utilizing vapor deposition techniques, which may include sputtering and ionization.

BACKGROUND OF THE INVENTION 
This invention relates to a perpendicular type magnetic recording member 
and a manufacturing method therefor. Recently, a perpendicular type 
magnetic recording system and an optical magnetic recording system have 
attracted attention as new magnetic recording systems for high density 
recording. A magnetic film for these recording systems has to be a 
so-called perpendicular deposition magnetic film which has a magnetic 
anisotropy in the direction perpendicular to the plane of the film and has 
to satisfy the conditions of Ku.perp..gtoreq.2.pi.Ms.sup.2, 
Hc.perp.&gt;Hc.parallel. and Br.perp.&gt;Br.parallel.. 
Co is known to have a large magneto crystalline anisotropy in the c axial 
direction of a hcp structure thereof. For obtaining a perpendicular 
deposition magnetic film by making use of the magnetic anisotropy of Co, 
it is necessary to satisfy the requirements: (1) that the direction of the 
c axis thereof is substantially perpendicular to the plane of the film and 
(2) that the crystal magnetic anisotropy energy Ku is larger than an 
energy of diamagnetic field 2.pi.Ms.sup.2 generated in the direction 
perpendicular to the plane of the film. However, the Co film is large in 
the value of a saturation magnetization Ms, and therefore does not meet 
the foregoing requirement (2), so that a perpendicular deposition magnetic 
film cannot be made from Co. 
There has also been known, as one of the perpendicular-incidence deposition 
magnetic films, a Co--Cr system thin film. This film has been made by an 
evaporation process. However, the evaporation process is defective in that 
the vapor pressure of Co and Cr are largely different from each other, and 
consequently it is difficult to keep a uniform Co--Cr composition ratio 
for a long period of time during manufacturing of the magnetic film 
thereof. Also, a uniform magnetic film of a Co--Cr having a perpendicular 
magnetic property can be obtained only when its evaporation deposition 
onto a substrate is carried out when the substrate is heated to 
200.degree.-300.degree. C. In other words, the perpendicular-incidence 
deposition magnetic film cannot be obtained when the substrate is not 
heated. However, such heating results in curling of a tape-shaped 
substrate and warping of a substrate of a floppy disk. In order to prevent 
this, a heat resisting substrate has to be used, resulting in an increase 
in production cost. 
SUMMARY OF THE INVENTION 
A perpendicular type magnetic recording member comprising a 
perpendicular-incidence magnetic film on a substrate, the 
perpendicular-incidence magnetic film comprising a magnetic metal and 
oxygen, the magnetic metal being selected from the group consisting of 
ferro-magnetic metals and alloys thereof; and a method of manufacturing 
the perpendicular type recording member.

An objective of this invention is to provide a perpendicular type recording 
member free from the above difficulties and is characterized in forming a 
perpendicular deposition magnetic film comprising a composition of 
magnetic metal (Me) and oxygen (where the magnetic metal (Me) represents 
any one kind or more selected from magnetic metals and magnetic alloys, on 
a substrate, either directly or through a soft magnetic material coating 
layer. As for the magnetic metal (Me) it typically includes Fe, Co, Ni, a 
mixture thereof, and any alloy thereof. The soft magnetic material coating 
layer may be a permalloy or an amorphous film made of Fe, Co, Co--Zr or 
the like. 
Another objective of this invention is a method of manufacturing the 
above-described perpendicular type magnetic recording member. This method 
is characterized in that, while oxygen gas is introduced into a vacuum 
treatment chamber, a magnetic metal (Me) is vaporized so that atomic 
vapors thereof are deposited on a surface of a substrate at a 
substantially perpendicular-incidence angle to the surface thereof, and so 
that part of the metal vapors is oxidized; thereby, forming a 
perpendicular deposition magnetic film on the substrate represented by 
either a composition of (Fe.sub.x Co.sub.y Ni.sub.z).sub.1-m O.sub.m, 
where O.ltoreq.x.ltoreq.0.05, O.ltoreq.z.ltoreq.0.40, x+y+z=1 and 
0.15.ltoreq.m.ltoreq.0.50, or a composition of (Fe.sub.x Co.sub.y 
Ni.sub.z).sub.1-m O.sub.m, where 0.40.ltoreq.x.ltoreq.1.0, 
O.ltoreq.z.ltoreq.0.25, x+y+z=1 and 0.25.ltoreq.m.ltoreq.0.50. 
Examples of this invention will be explained with reference to the attached 
drawings. 
Initially, there will be explained a perpendicular type magnetic recording 
member having a perpendicular deposition magnetic film comprising a 
composition of Co and 15-50 at % 0, and a manufacturing method thereof. 
FIG. 1 shows a vacuum evaporation treatment apparatus for making the 
magnetic recording member of this invention comprising a vacuum treatment 
chamber 1, provided with a rotary cooling can 2 of cylindrical drum type 
and an electron beam evaporation source 3 comprising a crucible positioned 
just under the can 2. The chamber 1 is connected through a control valve 
to a vacuum pump (not shown). On respective sides of an upper space 
portion over the rotary can 2, an unwinding roller 4 and a winding roller 
5 are disposed and are arranged to be rotated by a motor (not shown). A 
tape-shaped substrate a made of a non-magnetic material, such as a PET 
material, is mounted on the unwinding roller 4 and is arranged to be 
unrolled and run at a constant speed around a circumferential surface of 
the water-cooled can 2 and finally to be taken up by the winding roller 5. 
According to this invention, there is provided a supply pipe 6 for 
introducing oxygen into the chamber 1. A control valve may be interposed 
in pipe 6 as illustrated. The supply pipe 6 of an appropriate length is so 
that its open end is located near the surface of the running tape 
substrate a. Right and left vapor-adhesion shield plates 7 are so disposed 
as to leave a space interval 8 therebetween at which space the lowermost 
surface of the can 2 faces the evaporation source 3 below, so that Co 
atoms evaporated from the evaporation source 3 may pass through the space 
interval 8 and be deposited on the surface of the tape substrate a 
substantially perpendicular to the surface of the substrate a. The plate 7 
may be arranged so that it can move to the right or left, if desired. An 
electron beam heating means 9 is also provided. 
A magnetic recording member according to this invention can be manufactured 
by using the above-described apparatus as follows: 
After the interior of the chamber 1 is evacuated to below 1.times.10.sup.-5 
Torr, a raw ferro-magnetic metal material b to be evaporated, Co metal, 
for instance, is caused to evaporate at a constant speed from the 
evaporation source 3 by electron beam heating; and at the same time, 
O.sub.2 gas is introduced into the chamber 1 through the supply pipe 6 for 
oxidizing part of the Co vapors, and the partially oxidized Co vapors pass 
through the space 8 and deposits on a substrate a passing over on the 
lower surface of the cooled can 2 substantially perpendicular or normal 
incidence upon the substrate a, so that there is formed a perpendicular 
deposition magnetic film comprising a composition of Co--O on the surface 
of the tape substrate a. In this operation, by varying the amount of 
O.sub.2 gas introduced, various partial pressures thereof can be obtained 
in the chamber. Thus, there can be manufactured a large number of 
perpendicular type magnetic recording members having Co--O perpendicular 
magnetic films comprising varying composition ratios of Co--O. Also, the 
resulting magnetic films may have a thickness in the range of 1000 
.ANG.-10000 .ANG., which is caused by varying the running speed of the 
tape substrate a. The magnetic properties of films obtained from varying 
the Co--O composition ratios were measured to determine the relationship 
between the Co--O composition ratios. These magnetic properties are shown 
in FIGS. 2A, 2B, 2C. As will be understood therefrom, as the O content is 
increased, both coercive force in the direction perpendicular to film 
surface Hc.perp. and a residual magnetic flux density Br.perp. thereof are 
increased, and if the O content becomes above 15 atom. %, both Hc.perp. 
and Br.perp. become higher than a coercive force in the direction parallel 
to film surface Hc.parallel. and a residual magnetic flux density of that 
Br.parallel. thereof, so that perpendicular deposition magnetic films can 
be obtained. However, if the O content is beyond 50 at %, the saturation 
magnetization value becomes zero, resulting in the loss of the magnetic 
properties of the film. 
FIG. 3 shows hysteresis loops resulted from a perpendicular magnetic film 
comprising a typical composition of Co--36 at % O. From FIG. 3, it is 
understood that this film is a sufficiently perpendicular magnetic one. In 
the above manufacturing operation, the films having any predetermined 
compositions in the range of Co--15.about.50 at % O, can be also 
manufactured by varying the evaporation rate of Co while controlling the 
amount of O.sub.2 gas introduced. The relationship between the two are 
generally in proportional to the incidence deposition frequencies of both 
the atoms upon the substrate, and therefore, if the Co evaporation rate is 
increased, it is necessary to increase the partial pressure of O.sub.2. As 
is clear from FIG. 2C, the perpendicular magnetic films comprising the 
Co--15.about.50 at % O compositions according to this invention have 
excellent coercive forces Hc.perp. in the range of about 400-1000 Oe, 
which are the best values for a perpendicular magnetic film. 
When a conventional magnetic recording member having the perpendicular 
deposition magnetic film comprising a Co--Cr composition are manufactured 
by the evaporation process, it is essential to deposite the Co and Cr 
atoms on a substrate which has been heated to 200.degree.-300.degree. C. 
Whereas, according to this invention, heating of the substrate is not 
required. 
Namely, a good perpendicular type magnetic film can be obtained by the 
present invention even when the substrate is cooled or is not heated so as 
to remain at a normal temperature. Thus, this invention can eliminate the 
defect of the conventional process, which limits the kind of a substrate 
used therein to an expensive heat-resisting plastic film, such as 
polyimide or the like. In other words, according to this invention, the 
material used as the substrate is not limited, and therefore, an 
inexpensive material having no heat-resistance, such as a PET film or the 
like, can also be used, because a good perpendicular type magnetic film 
can be obtained without heating the substrate. However, in the present 
invention, the substrate may be heated, if desired. 
Also, when manufacturing the conventional Co--Cr perpendicular type 
recording member by the evaporation process, control of the Cr composition 
ratio is difficult. Due to this difficulty, a uniform perpendicular 
magnetic film cannot be obtained in a continuous manufacturing operation 
over a long period of time. Also, the heating in the conventional process 
significantly curls or wraps the substrate. In contrast, the procedures of 
the present invention require maintaining a constant evaporation rate of 
Co and a constant flow rate of O.sub.2 gas; whereby, it is very easy to 
form a uniform perpendicular magnetic film on a substrate over a long 
period of time. Also, in the present invention, curling and warping of the 
substrate hardly occur when the substrate is not heated. Thus, the present 
invention is very useful for manufacturing of a floppy disk and a magnetic 
tape, or the like. 
The reason that the Co--O magnetic film of the present invention has the 
foregoing good magnetic properties is not clear but can be thought of as 
follows: 
When the Co atoms are deposited on the substrate at substantially 
perpendicular-incidence angle thereto, there is formed a coating film 
having a columnar structure thereof in which the c axis of the hcp 
structure is oriented in the direction perpendicular to the plane of the 
film. During this evaporation, part of the evaporated Co atoms is oxidized 
by the introduced O.sub.2 and the resultant CoO oxide or similar oxide is 
deposited on the substrate, so that there is formed such a film structure 
that the Co fine particles are coated with these non-magnetic oxides. 
Thus, the Co columnar particle has not only the magneto crystalline 
ahisotropy, but also, a shape anisotropy, whereby the perpendicular 
magnetic anisotropy of the film is imporved. With such a film structure, 
partially oxided as above, an average saturation magnetization value is 
lowered so as to meet the requirement of Ku.perp..gtoreq.2.pi.Ms.sup.2, 
whereby the required perpendicular magnetic film can be obtained. The 
diameter of the columnar Co particle is considered to be about several 
hundreds .ANG.- several thousands .ANG., and is a fine metal particle, and 
accordingly has a high coercive force. 
A minor amount of one or more of other elements may be mixed in the 
foregoing Co--O perpendicular magnetic film. This includes elements which 
make solid solution with Co and do adversely effect the h c p structure. 
For example, Cr, V, Mo, W, Rh, Ti, Re, etc., may be included therewith in 
a minor amount. 
In addition, it has been found that a perpendicular magnetic recording 
system, having an intermediate magnetic film interposed between a 
perpendicular magnetic film and a non-magnetic substrate, can decrease the 
electric current required for recording, while increasing reproduction 
out. This intermediate film may be formed from a permalloy or amorphous 
film of Fe, Co, Co--Zr, which has a comparatively soft magnetic property 
and a large saturation magnetization. Such a perpendicular magnetic 
recording member is manufactured by coating the foregoing intermediate 
magnetic film on a surface of the non-magnetic substrate, and then coating 
a perpendicular deposition magnetic film comprising a predetermined Co--O 
composition on a surface of the intermediate magnetic film, according to 
the above-described method of this invention. 
Furthermore, when the present invention is used to manufacture a floppy 
disc, the above intermediate magnetic film may be formed on one or both 
surfaces of the substrate, and then the perpendicular magnetic film 
comprising a predetermined Co--O composition is formed on one or both 
surfaces of the intermediate magnetic film. 
Another example of this invention will now be explained with reference to 
FIGS. 4-7. This example is directed to a perpendicular type magnetic 
recording member having a perpendicular deposition magnetic film 
comprising a predetermined Co--Ni--O composition and a manufacturing 
method thereof. Namely, the Co--Ni--O composition is (Co.sub.1-z 
Ni.sub.z).sub.1-m O.sub.m, wherein 0&lt;z&lt;0.40 and 0.15&lt;m&lt;0.50. The 
perpendicular type magnetic recording member having a perpendicular 
magnetic film comprising the foregoing Co--Ni--O composition is 
manfuactured by using the apparatus shown in FIG. 1 and in almost the same 
manner as the first embodiment of this invention. Namely, after the 
interior of the chamber 1 is evacuated to be below 1.times.10.sup.-5 Torr, 
a Co--Ni alloy or a mixture of Co and Ni metals mixed in a predetermined 
ratio is evaporated at a constant rate by an electric beam heating means, 
while O.sub.2 gas is introduced into the chamber 1 through the pipe 6, so 
that partially oxidized vapors of Co and Ni are deposited on a surface of 
the subsrate a running at a constant speed, substantially perpendicularly 
or normally thereto; thereby, forming a perpendicular deposition magnetic 
film comprising a predetermined Co--Ni--O composition. 
In this manufacturing method, the perpendicular type magnetic recording 
members having magnetic films comprising various Co--Ni--O compositions 
are prepared by varying the amount of O.sub.2 gas introduced to provide 
various O.sub.2 partial pressures in the chamber 1 or by varying the 
mixing ratio of Co to Ni to be evaporated. 
Also, by varying the running speed of the tape substrate a and/or varying 
the evaporation rate of Ni--Co, manufactured magnetic recording members 
having the magnetic films varied in thickness in the range of 1000 
.ANG.-10000 .ANG. can be manufactured. The relationship between magnetic 
films having different composition ratios of the Co--Ni--O, and their 
magnetic properties have been examined. The results obtained are shown in 
FIG. 4, FIG. 5 and FIG. 6. As shown in FIG. 4, as the O component is 
increased, Hc.perp./Hc.parallel. is increased and more than 15 atom % of O 
component makes the Hc.perp./Hc.parallel. ratio more than 1. With respect 
to a residual magnetic flux density Br.perp./Br.parallel., FIG. 5 shows 
that as the O component is increased, the same is increased, and more than 
15 atom % of the O component makes the same more than 1. However, as shown 
in FIG. 6, saturation magnetization becomes zero when the O compoenent is 
above 50 atom %. From the above results, it is apparent that the area 
surrounded by the oblique lines in these Figures, that is, in the 
composition range of (Co.sub.1-z Ni.sub.z).sub.1-m O.sub.m where O&lt;z&lt;0.40, 
0.15&lt;m&lt;0.50, will provide excellent perpendicular magnetic films in the 
present invention. FIG. 7 shows hysteresis loops of a typical 
perpendicular magnetic film comprising (Co.sub.0.9 Ni.sub.0.1).sub.0.7 
O.sub.0.3 of this invention, and it is clear therefrom that the film is a 
sufficient perpendicular magnetic film. Thus, when the O component is in 
the range of 15-50 at %, and Ni component ratio of Co and Ni is O&lt;Ni&lt;40 at 
%, satisfactory perpendicular magnetic films can be obtained. Beyond 40 at 
% of Ni content, the crystalline structure of the deposited metal grains 
becomes an f c c structure, which is greatly decreased in magneto 
crystalline anisotropy, so that a perpendicular magnetic film cannot be 
produced. 
In addition, this perpendicular magnetic film of the present invention 
which includes the Ni material has an improved corrosion resistance. The 
perpendicular coercive force of this magnetic film is about 400-1000 Oe 
which are the best values for a perpendicular type magnetic recording 
member. 
In manufacturing the above magnetic film within the above Co--Ni--O 
composition range, if the Co--Ni evaporation speed is changed, generally 
the O.sub.2 amount of gas introduced is also changed. 
Since the perpendicular incident deposition frequencies of the Co stoms and 
the Ni atoms and those of the O atoms on the substrate are almost 
proportional to one another, when the Co--Ni evaporation rate is 
increased, it is necessary to increase the partial pressure of O.sub.2 by 
increasing the amount of the O.sub.2 gas introduced. 
In this embodiment example of this invention, the substrate is cooled by 
the can 2, but it is not always necessary to cool the same. Good results 
also can be obtained when the substrate is not heated. When the substrate 
is not heated, no curling results and a good product is obtained. 
Thus, in this example, an inexpensive material can also be used as the 
substrate. 
Also, according to this invention, the vapor pressure of Co and that of Ni 
are almost equal, and therefore, even if the Co--Ni alloy of any 
predetermined component ratio is evaporated from a single common 
evaporation source 3, a desired predetermined composition of Co--Ni 
evaporation deposition can be obtained on the substrate. Consequently, in 
this case, if the O.sub.2 introduction amount is kept constant, a 
predetermined uniform Co--Ni--O composition magnetic film can be produced 
over a long period of time in a continuous manufacturing operation. 
The foregoing intermediate magnetic film, as mentioned in the first 
example, may also be interposed between the substrate and the 
perpendicular magnetic film of Co--Ni--O composition in this second 
example. 
Next, a third example of this invention will be explained with reference to 
FIGS. 8-14, as follows; 
The third example is directed to a perpendicular type magnetic recording 
member having a perpendicular magnetic film comprising a Fe--Co--Ni--O 
composition. 
The Fe--Co--Ni--O composition is (Fe.sub.x Co.sub.y Ni.sub.z).sub.1-m 
O.sub.m where O.ltoreq.x.ltoreq.0.05, O.ltoreq.z.ltoreq.0.40, x+y+z=1, 
0.15.ltoreq.m.ltoreq.0.50 or which is the region forming a hpc structure, 
or (Fe.sub.x Co.sub.y Ni.sub.z).sub.1-m O.sub.m where 
0.40.ltoreq.x.ltoreq.1.0, O.ltoreq.z.ltoreq.0.25, x+y+z=1, 
0.25.ltoreq.m.ltoreq.0.50, which is the region forming a bcc structure. 
A manufacturing method of the above magnetic recording members is carried 
out by using the foregoing apparatus 1 in almost the same manner as in the 
above two examples. 
The perpendicular incident deposition magnetic film thus obtained comprises 
a phase of a perpendicularly grown columnar ferro-magnetic grains of 
Fe--Co--Ni and a phase of a non-magnetic oxides thereof surrounding the 
columnar grains. 
A number of magnetic recording members having the Fe--Co--Ni--O composition 
system were prepared in which the composition ratios of the four elements 
are varied, and magnetic properties thereof were measured. The results are 
shown in FIG. 8. FIG. 8 illustrates that by partially oxidizing the 
composition ratios of Fe--Co--Ni in the two regions A and B surrounded 
respectively by the oblique lines, there can be obtained excellent 
perpendicular magnetic films. The A region is one forming a bcc structure, 
and the B region is one forming a hcp structure. As mentioned above, it is 
necessary, when making a perpendicular magnetic film, that the 
perpendicular magnetic anisotrpic energy Ku is larger than the diamagnetic 
field energy 2 .pi.Ms.sup.2 in the direction perpendicular to the phase of 
the film. In this case, as the perpendicular magnetic anisotropy, a 
magneto crystalline one and a shape one can be considered. It has been 
found that the perpendicular magnetic film of this invention has such a 
structure that the ferro-magnetic column grain phase of Fe--Co--Ni grown 
perpendicularly is surrounded by a non-magnetic phase of oxides of 
Fe--Co--Ni, and also the column grain is long in that the diameter of its 
short axis is about 200-1000 .ANG. and the diameter of its long axis is 
about 1000 .ANG.-l .mu.m, which illustrates this magnetic film of the 
present invention also has a large shape anisotropy. In addition, by X-ray 
diffraction, it has been found that in the B region the c axis of the hcp 
structure is oriented in the perpendicular direction, and also in the A 
region, the (100) direction of the bcc structure is oriented in the 
perpendicular direction, and both the axial directions are in the easy 
crystal magnetization directions, so that this magnetic film has the 
magneto crystalline anisotropy. 
Thus, the role of the oxygen introduction is to separate the perpendicular 
columnar grains from each other by the non-magnetic oxides and to decrease 
the saturation magnetization of the entire magnetic film for satisfying 
the condition of K.perp..gtoreq.2 .pi.Ms.sup.2. 
As the amount of oxygen gas introduced is increased, while the evaporation 
rate of Fe, Co, Ni is kept constant, the concentration of oxygen in the 
film is increased. At the same time, the size of the columnar grain is 
decreased and the separation thereof from the oxide is developed, so that 
the decrease in the saturation magnetization and the anisotropic field in 
the perpendicular direction are increased. As a result of many 
experiments, it has been found that the perpendicular magnetic film is 
obtained when the oxygen component is more than 25 at % in the A region 
and more than 15 at % in the B region; the effective perpendicular 
magnetic films can be obtained in the range of 15-50 at % in oxygen 
content in the A region and, the most effective films being in the range 
of 35-45 at % O; and in the B region, effective films can be obtained in 
the range of 15-50 at % in O.sub.2 content, the most effective films being 
in the range of 25-45 at % O. Namely, if the O content is beyond 50 at %, 
it causes the saturation magnetization to become zero. This is considered 
to result from the fact that the oxides are FeO, CoO, NiO or the mixed 
crystallines thereof in the automatic ratio of 1:1. 
The Hc.perp. of the perpendicular magnetic films, obtained by the foregoing 
two A, B regions added therein with the oxygen contents of the foregoing 
predetermined range, is about 400-1000 Oe, which are the best values for 
perpendicular magnetic recording members. Those values are obtained by 
using the apparatus as shown in FIG. 1 and in almost the same manner as in 
the foregoing examples, even when the substrate is not heated at a normal 
temperature, or in a case where it is cooled. The reason why good 
perpendicular magnetic properties can be obtained even when the substrate 
is not heated is considered to be due to the fact that the O atoms are 
easily diffused in or spread over the film surface. 
The conventional Co--Cr system perpendicular magnetic film is obtained with 
such a structure that Cr atoms are segregated around the crystal 
boundaries of the Co columnar grains to form non-magnetic phases 
separating the columnar grains from each other. For forming this 
structure, it is necessary to diffuse Cr atoms over the film surface. This 
can be achieved by raising the temperature of the substrate and cannot be 
achieved when the substrate is not heated or heated to a low temperature. 
Whereas, according to this invention, oxygen gas is introduced and easily 
diffused over the film surface, and even when the substrate is not heated, 
a good perpendicular magnetic film can be obtained. A manufacturing method 
of the above products is almost the same as the above two embodying 
examples. 
Further, the advantages from the manufacturing method are substantially the 
same as those in the above two embodying examples. Namely, there can be 
obtained a uniform magnetic film for a long period of time in the 
manufacturing operation, and no curling or warping of the product results. 
By using the foregoing apparatus shown in FIG. 1, almost in the same manner 
as in the two above examples, there were produced various perpendicular 
type magnetic recording members having perpendicular magnetic films with 
thicknesses in the range of 1000 .ANG.-10000 .ANG.. The magnetic 
properties of these magnetic members and alloy compositions thereof were 
measured. 
FIGS. 9 and 10 show the resultant values of Hc.perp./Hc.parallel. and 
Br.perp./Br.parallel. when the O.sub.2 component is kept constant 15 at % 
while the Fe--Co--Ni composition is varied in ratio thereof. As apparent 
therefrom, in the B region both Hc.perp./Hc.parallel. and 
Br.perp./Br.parallel. are more than 1. In the A region, 
Hc.perp./Hc.parallel. is more than 1, but Br.perp./Br.parallel. is less 
than 1. Thus, these A and B regions indicate that a predetermined 
perpendicular magnetic film cannot be produced when the O.sub.2 content is 
15 at %. It has also been found that in the fcc phase region outside the A 
and B regions, Hc.perp./Hc.parallel. and Br.perp./Br.parallel. are both 
less than 1, so that no perpendicular magnetic films can be produced in 
the fcc phase structure. Similarly, FIGS. 11 and 12 show a case including 
a constant content of 25 at % O, and indicate that there are produced 
perpendicular-incidence magnetic films in the A and B regions. FIGS. 13 
and 14 show a case including a constant content of 40 at % O and indicate 
that there are produced perpendicular magnetic films in the A and B 
regions. 
Also, in the third example, there may be manufactured perpendicular 
magnetic recording members having the above-described intermediate soft 
magnetic film interposed between the substrate and the perpendicular 
ferromagnetic film. 
Furthermore, in the present invention, a manufacturing method is provided 
for manufacturing a further improved perpendicular type magnetic recording 
member, which is characterized in that a magnetic metal (Me) in a vacuum 
treatment chamber is vaporized while O.sub.2 gas is introduced into the 
chamber for oxidizing part of vapors of the magnetic metal (Me). The 
vapors thereof are deposited on a substrate at a substantially 
perpendicular incident thereto; and, in the course of the perpendicular 
incident deposition of the vapors of the magnetic metal, part of the 
vapors is ionized, and thus a perpendicular deposition magnetic film 
comprising a predetermined composition of Me and O atoms is formed on the 
substrate. 
By this method of the present invention, the crystallization of 
ferro-magnetic columnar grains is improved and magneto crystalline 
anisotropy is increased. In addition, lattice defects in the columnar 
grains or subgrains can be eliminated and orderly oriented columnar grains 
can be obtained, so that shape anisotropy thereof is improved. 
In another aspect of this invention, the ionized vapors are accelerated to 
increased speed by an electric field of d.c. or a.c. power. Embodying 
examples of this aspect of the invention will be explained with reference 
to FIGS. 15-19. FIG. 15 shows an apparatus for carrying out the above 
manufacturing methods. This apparatus is different from the apparatus 
shown in FIG. 1, in that it is provided with additional mechanisms. 
Namely, in FIG. 15, the apparatus 1 is provided with an ionizing means. The 
ionizing means comprises an electrode 10 provided in a space located above 
the evaporation source 3 and a d.c. power source or a RF source 11 is 
connected to the electrode 10. The electrode 10 comprises an anode which 
is provided in connection with a positive d.c. current or a RF voltage for 
ionizing part of the metal vapors and oxygen at a high efficiency. In 
addition, the apparatus is provided with an acceleration means comprising 
a mesh-shaped electrode for acceleration which is located near the 
substrate portion running on the lower end surface of the can 2, and a 
d.c. or a.c. source 13 is connected thereto. 
By using this apparatus, a perpendicular type magnetic recording member can 
be manufactured as follows. Namely, the chamber 1 is evacuated to below 
1.times.10.sup.-5 Torr, and a predetermined composition of metal (Me) b is 
evaporated by being heated with electron beam heating means 9, while 
oxygen is introduced into the chamber 1 through the oxygen introduction 
pipe 6. The evaporating rate can be 200 .ANG./sec. and the partial 
pressure of O.sub.2 gas can be 1.times.10.sup.-4 Torr. Under these 
conditions, a positive d.c. voltage is applied to the anode 10 connecting 
to the d.c. power source 11. Whereupon, electrons from the electron beam 
and a secondary electrons from the evaporating liquid surface of the metal 
(Me) are attracted to the positive electric field, whereupon the metal 
vapors and oxygen atoms collide with these electrons in the electric field 
space and are ionized, Namely, a comparatively greater part of the ionized 
metal vapors can be ionized, because while these electrons are being 
attracted to the positive electric field by the positive voltage 
application to the anode 10, the metal vapors are brought into contact 
with such attracted electrons. In this way, a greater part of the oxygen 
atoms also can be ionized. 
The ionization of the metal vapors and oxygen atoms can be carried out by 
the application of the positive electrode voltage by using the RF electron 
voltage instead of direct current. When using RF voltage, the RF source 
also serves as an electron generating source, so that it becomes 
unnecessary to use the electron beam means as the heating means 9, and the 
non-electron beam type heating means such as an ordinary electric heater 
or the like can be used in place of the electron beam type heating means. 
Thus, when the vapors of magnetic metal have been partially ionized 
together with the oxygen gas and pass through the space 8 between the 
plates 7, 7, they are deposited onto the lower surface of the tape 
substrate a running beneath the lower surface of the can 2, at a generally 
perpendicular incidence on the surface of the substrate, so that there is 
formed a partially ionized and oxidized perpendicular magnetic film. 
In the above method of this invention, Co metal may be used as the 
ferro-magnetic metal (Me), and the evaporating rate and the O.sub.2 gas 
partial pressure are set at 200 .ANG./sec. and 1.times.10.sup.-4 Torr, 
respectively. However, the ionizing electric current for applying a 
positive voltage to the anode 10 is varied, so that there are manufactured 
perpendicular type magnetic recording tape members having various 
perpendicular magnetic films of a Co--O system. In these products, there 
is a relationship between the change in the ionizing electric voltage and 
magnetic properties of the products. For comparison, various perpendicular 
type magnetic recording tape members having various perpendicular magnetic 
films of a Co--O system were manufactured by the above method, without a 
d.c. current applied to the anode 10. The resulting magnetic properties 
thereof were examined. The results are shown in FIG. 16. As is clear 
therefrom, the values of Hc.perp./Hc.parallel. and Br.perp./Br.parallel. 
are the lowest in regard to the magnetic films manufactured without 
application of the positive electric voltage to the anode 10; and 
accordingly, as the voltage applied thereto is increased, these values are 
increased. In this case, it has been found that these values become almost 
constant at the ionizing electric current of about 3 A or more. 
According to the additional manufacturing method, the previously 
positive-charged metallic vapors are subjected to an acceleration negative 
voltage through the mesh-shaped electrode 12 which is connected to the 
d.c. source 13. This results in the vapors being accelerated to increased 
speed, and consequently, the reaction between the accelerated metal atoms 
and oxygen atoms, as well as the surfacial diffusion of the metallic 
atoms, is increased. Thereby, there can be provided on the substrate, a 
perpendicular magnetic film which is higher, in the foregoing magnetic 
properties of Hc.perp./Hc.parallel. and Br.perp./Br.parallel., than the 
foregoing perpendicular magnetic films formed without the acceleration 
means. 
Further, if an a.c. power is used instead of the d.c. power, a positive 
electric voltage and a negative one may be applied alternately to the 
electrode 12. Each time the negative voltage is applied, the ionized 
metallic vapors are accelerated thereby, and in addition, each time the 
positive voltage is applied, the negative-charged O atoms are accelerated, 
so that a uniform reaction between the metallic vapors and the oxygen 
atoms, as well as the diffusion thereof, can be improved when compared to 
the use of d.c. power. 
Various perpendicular type recording members having various perpendicular 
magnetic films of Co--O system were manufactured by setting the ionizing 
electric current to 2.0 .ANG. and the acceleration voltage applied to the 
acceleration electrode 14 from the d.c. or a.c. powder was varied. The 
relationship between the acceleration electric voltage and the magnetic 
properties of the resulting films was examined. The results thereof are 
shown in FIG. 17. As is clear from FIG. 16, and FIG. 17, the values of 
Hc.perp./Hc.parallel. and those of Br.perp./Br.parallel. of the a.c. and 
d.c. powers is improved if the acceleration voltage is used when compared 
to not using the acceleration voltage. Also, as the acceleration electric 
voltage is increased, the respective properties are also increased. 
Further, if the substrate is made of an electric insulating material such 
as polyethylene terephthalate (PET) or the like, the use of the a.c. power 
is preferable. 
FIGS. 18 and 19 show the results of examining the relationship of the 
ionizing current and the acceleration voltage in conjunction with magnetic 
properties of perpendicular magnetic films of Fe--Co--Ni--O composition 
manufactured by the above method of this invention using the apparatus 
shown in FIG. 15. This examination used a Fe-10% Co-10% Ni alloy as the 
evaporating material metal b. From FIGS. 18 and 19, it is understood that, 
in a similar manner to the above example case of a Co--O composition film, 
the ionization and acceleration effects can be recognized. 
As a result of many experiments and examinations, it has been found that 
perpendicular magnetic films of Me.sub.1-m O.sub.m, improved in those 
properties according to this invention method, can be obtained in such a 
metal and oxygen composition range as follows: (Fe.sub.x Co.sub.y 
Ni.sub.z).sub.1-m O.sub.m where O.ltoreq.x.ltoreq.0.05, 
O.ltoreq.z.ltoreq.0.40, x+y+z=1, and 0.15.ltoreq.m.ltoreq.0.50 or 
(Fe.sub.x Co.sub.y Ni.sub.z).sub.1-m O.sub.m where 
0.40.ltoreq.x.ltoreq.1.0, O.ltoreq.z.ltoreq.0.25, x+y+z=1, and 
0.25.ltoreq.m.ltoreq.0.50. 
In the foregoing embodying examples, the perpendicular magnetic film may 
have the soft magnetic material film between the substrate and the 
magnetic film. 
According to another manufacturing method of this invention, the 
perpendicular type magnetic recording members having the perpendicular 
magnetic film comprising the Me--O composition can be manufactured by a 
sputtering process. This method is characterized in that a target 
comprising a magnetic metal (Me) in a vacuum treatment chamber is 
sputtered while O.sub.2 gas is introduced thereinto; and the sputtered 
magnetic metal particles are deposited on a surface of a substance at 
substantially perpendicular angle thereto, while part of atoms of the 
innumerable sputtered particles of magnetic metal (Me) is oxidized, so 
that a perpendicular-incidence magnetic film having a predetermined 
composition of magnetic metal (Me--O) atoms is formed on the substrate. 
Thus, there can be obtained a perpendicular type magnetic recording member 
which is improved in the Hc.perp./Hc.parallel. property and the 
Br.perp./Br.parallel. property. 
In order to further improve the magnetic properties of the film resulting 
from the above manufacturing method, an additional manufacturing method is 
provided. This method is characterized in that a target of the magnetic 
metal (Me) and an electrode comprising the substrate itself or one near 
the substrate are provided in the vacuum treatment chamber. This method is 
carried out by applying a negative electric voltage or an alternate 
voltage to the electrode and by sputtering the target, while O.sub.2 gas 
is introduced into the chamber so that innumerable sputtered magnetic 
metal (Me) fine particles are deposited on the substrate at substantially 
perpendicular-incidence angle thereto. During this procedure, some atoms 
thereof are oxidized, so that there is formed on the substrate, a 
perpendicular magnetic film comprising a predetermined composition of 
magnetic metal (Me--O) atoms. 
FIGS. 20-25 show embodying examples of the foregoing methods of this 
invention. Referring to FIG. 20, the apparatus 1 is one for carrying out 
those manufacturing methods of this invention. The apparatus is almost the 
same as that shown in FIG. 1 and FIG. 15, but is different therefrom in 
that instead of an evaporation method, a sputtering method is provided 
therein. Namely, just under the can 2, there is provided a sputtering 
cathode 14 on which the ferro-magnetic metal target b is provided, and 
preferably, the mesh-shaped acceleration electrode 10 connecting to the 
d.c. or a.c. power source 11 is located near the surface of the substrate 
a running on the lower end surface of the can 2. Numeral 15 denotes an 
introducing pipe for introducing a sputtering gas, such as Ar or the like 
into the chamber 1. For carrying out this invention, the apparatus can be 
operated as follows: The chamber 1 is evacuated to below 1.times.10.sup.-5 
Torr, and Ar gas is introduced into the chamber 1 through the introducing 
pipe 15, and the metal (Me) target b is sputtered under an Ar gas pressure 
of 5.times.10.sup.-3 Torr. The sputtering is carried out by a d.c. 
magnetron sputtering process. Whereupon, a comparatively large amount of 
innumerable sputtered Me atoms, usually about 10% thereof, become ionized 
atoms. The energy generated at the time when the Me atoms are sputtered is 
comparatively high (about 10-100 eV) and can serve to produce the 
perpendicular magnetic films of the Me--O system which has improved 
perpendicular magnetic anisotropy. 
On the other hand, O.sub.2 gas is introduced at a constant flow rate into 
the chamber 1 from the oxygen supply pipe 6, and is brought into contact 
with the rising sputtered and partially-ionized metal (Me) atoms, so that 
part of the metal atoms is oxidized, whereby, mixed vapors of the metal 
atoms and the oxidized ones are deposited on the substrate running at a 
predetermined constant speed, through the interval or space opening 8, at 
a substantially perpendicular-incidence angle thereto, so that there is 
formed on the surface of the substrate a perpendicular magnetic film of a 
predetermined composition comprising two phases of the magnetic metal (Me) 
atoms and non-magnetic oxides thereof, and thus the perpendicular magnetic 
recording film is wound onto roller 5. 
According to another method of this invention, during the operation of the 
above method, the negative voltage is applied to the acceleration 
electrode 10 from the d.c. power source 11, so that there is created a 
negative electric field therearound. This results in that the foregoing 
partially ionized sputtered positively-charged metal (Me) atoms are 
accelerated to increased speed by the electrode 10, by being drawn upwards 
into the negative electric field. When the power source 11 is a.c., the 
electrode 10 can be provided with an alternate application of positive and 
negative electric voltages; whereby, there is an acceleration of ionized 
Me atoms and an acceleration of partially ionized O atoms which improve 
results. Consequently, a reaction and a diffusion can be carried out 
effectively near the mesh-shaped electrode 10 between the sputtered metal 
Me atoms and the oxygen atoms, and accordingly, there can be formed a good 
perpendicular magnetic film of the composition of metal and O atoms 
comprising two phases of metal (Me) atoms and oxides thereof, which are 
uniformly diffused on the entire surface of the substrate a. If the 
substrate material is an electric insulating material, use of the a.c. 
voltage application is preferable in view of preventing the same from 
becoming electrically charged. When an electrically conductive substrate 
is used, the same can be arranged to be used as an acceleration electrode 
by being connected to the a.c. or d.c. power source (not illustrated). 
In FIGS. 21 and 22, curves A and A' respectively show perpendicular 
magnetic properties Hc.perp./Hc.parallel. and Br.perp./Br.parallel. of 
various perpendicular magnetic film prepared, according to this invention, 
by varying the composition ratio of oxygen to Co which is used as the 
target b. Also, in these Figures, curves B and B' respectively show 
magnetic properties of various perpendicular magnetic films of the same 
composition ratio of Co--O as prepared above in the first example, in 
which Co is evaporated by the electron beam heating means while O.sub.2 is 
introduced into the chamber and the film is deposited on the substrate at 
substantially perpendicular angle. As is clear from these curves, the 
magnetic properties of the Co--O perpendicular incidence magnetic films 
prepared by the sputtering process are more excellent than those prepared 
by the evaporation process. 
FIG. 23 and FIG. 24 respectively show perpendicular-magnetic properties A, 
A' of various perpendicular magnetic films of Fe--Co--Ni--O prepared by 
using a 10% Co-10% Ni-remainder Fe alloy (Fe.sub.0.8 --Co.sub.0.1 
--Ni.sub.0.1) as the target b, while the O constant is varied from 0 to 50 
at %. These films were prepared by the sputtering process. These Figures 
also show the perpendicular magnetic properties B, B' of various 
perpendicular magnetic films of the same composition prepared, for 
comparison, by the foregoing proposed evaporation process of this 
invention. It is also understood from these curves that the perpendicular 
magnetic properties of the products prepared by the sputtering process of 
this invention are better than those of the products prepared by the 
evaporation process of this invention. 
FIG. 25 shows curves of the magnetic properties of perpendicular-incidence 
magnetic films of a Co.sub.0.7 --O.sub.0.3 composition respectively 
prepared by respectively applying acceleration voltages of the d.c. 
voltage and the a.c. voltage during deposition of the sputtered Co atoms 
on the substrate while O.sub.2 gas is introduced. 
As is apparent therefrom, the Hc.perp./Hc.parallel. and 
Br.perp./Br.parallel. can be improved by the use of the acceleration 
voltages, and the application of a.c. voltage provides increased 
improvement in these properties, when compared to the d.c. voltage. 
The perpendicular magnetic films of the Me--O composition prepared by the 
sputtering process of this invention can be obtained with (Fe.sub.x 
Co.sub.y Ni.sub.z).sub.1-m O.sub.m where 0.ltoreq.x.ltoreq.0.05, 
O.ltoreq.z.ltoreq.0.40, x+y+z=1, and 0.15.ltoreq.m.ltoreq.0.50, or with 
(Fe.sub.x Co.sub.y Ni.sub.z).sub.1-m O.sub.m where 
0.40.ltoreq.x.ltoreq.1.0, O.ltoreq.z.ltoreq.0.25, x+y+z=1 and 
0.25.ltoreq.m.ltoreq.0.50. In order to obtain magnetic films within these 
compositions, the amount of oxygen introduced, sputtering process, and the 
running speed or velocity of the substrate are controlled. In general, the 
film thickness thereof prepared by the sputtered process of this invention 
is in the range of 1000-10000 .ANG.. Before the substrate is subjected to 
the sputtering process of this invention, it may be coated with the soft 
magnetic material film of permalloy or the like, as described above. 
Thus, according to this invention, a method of manufacturing a 
perpendicular magnetic recording member is provided, wherein a 
perpendicular magnetic film is deposited on a substrate from vapors of 
ferro-magnetic metal (Me) at a substantially perpendicular-incidence angle 
to the substrate, while an oxygen gas is introduced into the chamber. 
Thus, a perpendicular magnetic film of Me--O composition having improved 
magnetic properties can be uniformly and continuously obtained over a long 
period of time, without heating the substrate and without curling or 
warping of the substrate. In a preferable aspect of this invention film, 
the vapors of the ferro-magnetic metal are ionized or additionally 
accelerated to increased speed by application of the electric voltage, 
which further improves the magnetic properties such as 
Hc.perp./Hc.parallel. and Br.perp./Br.parallel. Further, if the 
composition ratio of Me and oxygen atoms of the magnetic film of this 
invention comprises (Fe.sub.x Co.sub.y Ni.sub.z).sub.1-m O.sub.m where 
O.ltoreq.x.ltoreq.0.05, O.ltoreq.z.ltoreq.0.40, x+y+z=1 where 
0.15.ltoreq.m.ltoreq.0.50 and/or (Fe.sub.x Co.sub.y Ni.sub.z).sub.1-m 
O.sub.m are in the region where 0.40.ltoreq.x.ltoreq.1.0, 
O.ltoreq.z.ltoreq.0.25,x+y+z=1 and 0.25.ltoreq.m.ltoreq.0.50, 
perpendicular type magnetic recording members which are excellent in 
magnetic properties can be obtained.