JPS60182511A - Magnetic recording medium - Google Patents

Abstract

PURPOSE:To obtain a recording medium having high coercive force and residual magnetic flux density, a small characteristic change owing to a temp. change and good stability in recording magnetization by forming the medium in such a way that the rate of the change in the coercive force with temp. of a magnetic layer consisting essentially of a Co-Ni alloy and the compsn. of the magnetic layer satisfy the specific relation. CONSTITUTION:A thin magnetic alloy film layer 3 consisting essentially of Co1-xNix (0<=x<=0.5) is formed on a substrate 1 consisting of polyester, polyimide, glass or a metallic sheet such as Al sheet subjected to an oxidation treatment on the surface directly or after an underlying layer 2 consisting of non- magnetic metals which are metals such as Bi, Sb, Gs, Si, etc. or the alloys, intermetallic compds., etc. thereof is deposited thereon by evaporation. The content of Ni is so determined that the rate of change in the coercive force Hc with temp. of such magnetic layer 3 Y=Hc1/Hc2 (where Hc1 is the coercive force at 100 deg.C and Hc2 is the coercive force at -196 deg.C) satisfies the relation Y>=0.27+ 0.85x. The change in Br/Hc between the residual magnetic flux density Br and the coercive force Hc with temp. is thus decreased and the magnetic recording medium having high stability in recording magnetization with temp. is obtd.

Description

[Detailed description of the invention] J+7 industry 1 publication l1lr 4. The invention is based on the magnetic recording medium 4:j (:0 old alloy 1-
Yusei L Igi (rL'), which is a component of magnetic recording media.

−? Sato technology and its problems 111 years, magnetic recording +I'b (+i I1ization θ month 1
For the target recording medium, a strong metal layer with a thickness of 1 tt is formed on a non-aqueous support by a force method such as vacuum if; i + i, sputter link, etc. There is a lot of research going on in the field of magnetic recording media.
．． L, Hanyu) Month 1 (2, medium density 11r is desired for each use of the remaining '8Hd'. Also, which 11.!111;
To the temperature change? -1-111- and depending on the temperature of Ilr/Ilc? ] The fact that there is little change in temperature is a record.There are some cases where Rikishima is excluded due to the slowness of the change in temperature.

When considering a change of 11.14 degrees in 11r/llc, 1.
1 r is equal to B r/Hs or E change and Schiff' (saturation 1 ■ temperature dependence of magnetic flux density 1'ls).

(Co1-xNix alloy (O≦X
≦0.5) It S +7) tll,! A 1 degree change uses 1 Curie-6 degree of emotion, so for example (,1゜1 O(1
'c4) It is only about a 5% decrease compared to absolute zero,
Another force with little change, anti (4 months 1c (7) i'A+
Although the cause of the phase change varies depending on the cause of the difference in temperature in the magnetic III layer, the Ilr/Ilc ii! The smaller the change in A degree, the better.
)? 7A Degree Change A 1 Agriculture 303 ``Immediate #)' IIs lAA
1. Q - close to change (desired; L).

Invention 1-1 rl'J In view of the above-mentioned points, the present invention provides IJ'l: Takuka 11 (,
C12(1・re, 11r/Ilc〆111!L There are magnetic recording media with small degree change called i4 and '4'C.

4111 Essentials of the Invention The present invention provides Got-X N tx gold alloy 0≦X≦0.5
) in a magnetic recording medium having a magnetic layer having one component, the temperature change rate Y =
1lct/fla2 (however, 11C1 is 100℃
The coercive force at 196°C is the coercive force at 196°C.
is a magnetic recording medium that satisfies the relationship y≧0.27+0.85x.

The magnetic recording medium of the present invention has excellent antimagnetic resistance 1c and small temperature change in Br/lic, resulting in stable recording magnetization.

Example The above is a description of the ninth embodiment of the present invention.

Example 1 In a vacuum chamber at a pressure of 10-1' Torr, an old film was placed on a non-magnetic support (11) made of polyimide film with the support temperature maintained at 150°C as shown in Figure 1. A base layer (2) is formed by evaporation by 100 people,
Subsequently, Cot-xNix alloy was deposited by 350 people to form a metal magnetic layer (3). At this time, Cod-xNix
The amount of Ni in the alloy is x = 0.0.1.0.2.0.3.0
．． 35.0.4.0.5 and each magnetic recording medium was produced. Example I The magnetic recording medium thus obtained was
grouped.

Example 2 The same method as in Example 1 was used, but Bi'to (2) was deposited by 1 yen and 70 people, and then J-striped by 350 people.
ot-xNix alloy is deposited, at this time Cot-xNt
The amount of Ni in x alloy is X=0.0.1.0.2.0.3.0
．． 35.0.4.0.5 and each magnetic recording medium was produced. The magnetic recording medium obtained in this way was used as Example ①
grouped.

Comparative Example 1 After exhausting the pressure inside the vacuum chamber to 1O-6Tprr or less, oxygen gas was pumped in at 120cc/cm from the leak valve.
A metal magnetic layer ( 3) was formed (Bi underlayer was not deposited)
. When Co1-x N ix gold alloy Ni amount x = 0
．． 0.1.0.2.0.3.0.35.0.4゜0.5
Each magnetic recording medium was manufactured by changing the following. The magnetic recording media thus obtained were designated as Comparative Example 1 group.

- described in Example 1. Temperature change rate of coercive force 11c for each magnetic recording medium of Group II and Comparative Example 1 at room temperature (20°) (C and composition
IC2 [However, l1cl is the coercive force at 100℃, 1lc
2 is the coercive force at -196°C (liquid nitrogen'/i+&degrees)] is written in the dotted line.

Table 1 - Example [21Y ■ Table 2 - Example 11 Group'' Table 3 - Comparative Example 1 Group'' The temperature change rate y of the coercive force Hc of Example I and Group ■ is Comparative Example 1
It is larger than that of the group, and y also increases linearly as NiF#x does not increase. On the other hand, in Comparative Example 1 group, N1Jt
Even if ix changes, y does not change much.

Example ①: A magnetic layer similar to that of group 11 was formed on a Bi underlayer.
The same coercive force ti was obtained by changing the center thickness and support temperature.
c was measured. As a result, the relationship between X and y in Example 1, group
The temperature change rate of ic has the same tendency, y = a + b
It turned out to be X. Example ■: A number of samples with the same tendency were prepared in addition to the first group, and x,! As a result of determining the relationship between y and y, the constants a and b of x were a-0, 3±O, 03, and b=0.95±0.1, respectively.

C0I-X Nix gold alloy 0≦X≦0 according to this example
．． 5) has the characteristic that the temperature change rate y of the coercive force 1c is uniquely determined by the composition X, and as the amount of Ni increases, the coercive force 11
The temperature change rate y of c increases. That is, the temperature change itself in the coercive force 11c becomes gradual.

Cot-xNix alloy (0≦X≦0.5) from below-1-
In a magnetic layer mainly composed of
+ 0.85 If the 1vi coefficient of x is satisfied, Br/l
lc's lA! This reduces the phase change and increases the stability of recorded magnetization against temperature. Also like this Cot-x N ix
In the alloy magnetic layer, if the composition of X is known, the 414 of its Ilc
Since the degree change can be seen, this is a great advantage when putting magnetic recording media into practical use. In addition, in the magnetic recording medium of this example, since the (:o]-xNi×alloy magnetic layer (3) is formed on the non-magnetic underlayer (2) such as Bi, the resistance is 11 J by the eastward evaporation. The magnetic force 11c is suppressed and the magnetic properties are in-plane isotropic.

JY; J, Magnetic recording medium G according to the present invention C1 Its non-magnetic support (, 5 ('') and 'ζ are, for example, polyenalene derephthalate, polyamide, polyamide'imide.

Polymer films such as polyimide, glass, ceramics,
A metal plate or the like oxidized with G-Fi 7 or Table 1h1 can be used. In addition, as the upper layer (2), 41 of Bi
'l, Sb, Ga, Ge+! Nonmagnetic metals that expand in volume upon solidification, such as +, alloys thereof, and intermetallic compounds, can be used.

Effects of the Invention According to the present invention described above, Cox-xNix alloy (0≦
In a magnetic recording medium having a magnetic layer whose main component is X≦0.5), the temperature change rate y of the coercive force 11c of the magnetic layer should not satisfy the relationship y≧0.27+0.85x. The coercive force can be obtained by Br/1.
The temperature change in 1c is reduced, and the stability of recorded magnetization with respect to temperature can be increased.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a cross-sectional view showing an example of the magnetic recording medium of the present invention.
FIG. 2 is a neo-sectional view of a comparative example of a magnetic recording medium used to explain the present invention. (1) is a non-magnetic support, (2) is an underlayer, (3) is C0
1-X N ix, alloy magnetic layer.

Claims (1)

[Claims] 1] O+-x N i x alloy (0≦x S O, 5)
-) The mother 1 and 11 states are (-1' years old)
;+% Medium G, Nioi-(, 1st (jon soup 1j busy → Q month)' [, Ikukuno month b: (7) 11, 14 degree change"!
'3'-1tch, / 1lc2 (However, Ib:l
11. I fl(1't knee(?'s coercive force, llc:
2 is I! Ifi'c's coercive force) is y < 0.27
1-0.85 Express the relationship of x: ;Dashiku Ij! magnetic recording media.