JPH0628088B2 - Magnetic recording medium - Google Patents

Description

【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、特に浮上型リングヘツドで記録再生の行なわ
れる磁気デイスクといつたような水平磁気記録方式に好
適な磁気記録媒体に関するものである。Description: FIELD OF THE INVENTION The present invention relates to a magnetic disk for recording / reproducing on a floating ring head and a magnetic recording medium suitable for a horizontal magnetic recording system.

〔従来技術とその問題点〕[Prior art and its problems]

近年、高密度記録の為に、例えばCo、Co-Ni、Co-Ｐ又は
Co-Ni-Ｐ等の磁性材料を基体上に、例えばスパツタ、電
気メツキ又は無電解メツキ等の手段で形成した金属薄膜
型磁気記録媒体が提案されている。In recent years, for high density recording, for example, Co, Co-Ni, Co-P or
There has been proposed a metal thin film type magnetic recording medium in which a magnetic material such as Co-Ni-P is formed on a substrate by means such as sputtering, electric plating or electroless plating.

しかし、この種の磁気記録媒体は耐食性に劣つており、
高湿度な条件下で用いられるには問題があり、そこで金
属磁性薄膜層上に防錆層を設けることが提案されている
のであるが、このような手段が講じられると、製造工程
の複雑化等によりコスト高なものとなり、かつ磁気ヘツ
ドのスペーシングの増大となるので再生出力の低下とな
り、必ずしも望ましいとは言えない。However, this type of magnetic recording medium has poor corrosion resistance,
There is a problem in using it under high humidity conditions, and it has been proposed to provide an anticorrosion layer on the metal magnetic thin film layer, but if such measures are taken, the manufacturing process becomes complicated. As a result, the cost becomes high, and the spacing of the magnetic head increases, so that the reproduction output decreases, which is not always desirable.

そこで、より耐食性に優れた磁性材料としてCo-Cr系合
金が注目を集めている。又、このCo-Cr系磁性合金は、
垂直異方性に富むことより、短波長領域での自己減磁の
問題が少ない垂直磁気記録方式に適したものであるとい
つた面よりも注目を集めている。Therefore, Co-Cr alloys have been attracting attention as a magnetic material having more excellent corrosion resistance. Also, this Co-Cr magnetic alloy is
Due to its rich perpendicular anisotropy, it has attracted more and more attention as being suitable for a perpendicular magnetic recording system which has less problems of self-demagnetization in the short wavelength region.

すなわち、Co-Cr系磁性合金薄膜型磁気記録媒体は、バ
インダーを用いないことより高密度化が図れ、又垂直磁
気記録方式のものであることより高密度化が図れ、又、
比較的耐食性に優れているといつたことより注目を集め
ており、このようなことから大きな研究が集中的に行な
われている。That is, the Co-Cr-based magnetic alloy thin film type magnetic recording medium can be made higher in density by not using a binder, and can be made higher in density by being a perpendicular magnetic recording system.
It has been attracting attention for some time that it is relatively excellent in corrosion resistance, and for this reason, a great deal of research is being conducted intensively.

そして、高密度化の為に、例えば垂直磁気異方性向上の
為に、酸素原子を含むガス雰囲気下でCo-Cr系磁性粒子
を高速析出し、基材面上に酸素原子が約２〜８原子％偏
析含有しているCo-Cr系垂直磁化膜を構成した磁気記録
媒体が提案（特開昭５９−１７２１６号）されている。Then, in order to increase the density, for example, to improve the perpendicular magnetic anisotropy, Co—Cr magnetic particles are rapidly deposited in a gas atmosphere containing oxygen atoms, and the oxygen atoms on the surface of the base material are about 2 to 2 A magnetic recording medium comprising a Co—Cr perpendicularly magnetized film containing 8 atom% of segregation has been proposed (JP-A-59-17216).

ところが、現行の記録再生装置、つまりリング型磁気ヘ
ツドの用いられている記録再生装置では、特に浮上型リ
ングヘツドの用いられている記録再生装置では垂直磁化
型のものは水平磁化型のものより再生出力が小さいとい
つた大きなデメリツトがあり、特開昭５９−１７２１６
号提案のようなCo-Cr系垂直磁化膜の磁気記録媒体は必
ずしも優れたものではない。However, in the current recording / reproducing apparatus, that is, in the recording / reproducing apparatus using the ring type magnetic head, particularly in the recording / reproducing apparatus using the floating ring head, the vertical magnetization type reproduces the reproduction output more than the horizontal magnetization type. When it is small, there is a big demerit, and it is disclosed in JP-A-59-17216.
The magnetic recording medium of the Co-Cr system perpendicular magnetic film like the proposal is not necessarily excellent.

〔発明の開示〕[Disclosure of Invention]

本発明者は、Co-Cr系合金膜が比較的耐食性に優れてい
ること、及び高密度記録の面で望ましい金属薄膜型のも
のであることに鑑み、大きな再生出力を得ることの出来
る水平磁化型のCo-Cr系合金磁性膜とする研究を重ねた
結果、非磁性基体上に設ける磁性膜は、酸素原子を９．
７〜１４．１原子％含むCo-Cr系非晶質合金であればよ
いことを見い出した。In view of the fact that the Co-Cr alloy film is relatively excellent in corrosion resistance and that it is a metal thin film type that is desirable in terms of high density recording, the present inventors have proposed a horizontal magnetization that can obtain a large read output. As a result of repeated research into a Co-Cr type alloy magnetic film of the type I, the magnetic film provided on the non-magnetic substrate contains oxygen atoms of 9.
It has been found that a Co—Cr-based amorphous alloy containing 7-14.1 at% may be used.

つまり、酸素原子を９．７〜１４．１原子％含むCo-Cr
系非晶質合金磁性膜の孤立再生波形を調べると、垂直磁
化膜を示す双峰性パルス状のものではなく、水平磁化膜
固有の特徴である単峰性パルスであり、このことから疑
いもなく酸素原子を９．７〜１４．１原子％含むCo-Cr
非晶質合金磁性膜は水平磁化型のものである。That is, Co-Cr containing 9.7 to 14.1 atomic% of oxygen atoms
Examination of the isolated reproduction waveform of the system amorphous alloy magnetic film reveals that it is not a bimodal pulse shape showing a perpendicular magnetization film, but a monomodal pulse which is a characteristic peculiar to a horizontal magnetization film. Co-Cr containing 9.7 to 14.1 atomic% oxygen atoms
The amorphous alloy magnetic film is of the horizontal magnetization type.

そして、例えば浮上量0.25μｍのリングヘツドで再生出
力を調べると約0.8ｍＶ以上のものが得られ、高出力の
得られるものである。Then, for example, when the reproduction output is examined with a ring head having a flying height of 0.25 μm, a reproduction output of about 0.8 mV or more is obtained, and a high output is obtained.

〔実施例１〕 Arガス圧100mTorr、ターゲツトに加える電力密度1.0Ｗ
／cm²、スパツタレート130Å／分の酸素雰囲気スパツタ
条件下でCo-Crをスパツタリングして、非磁性基体上に
0.20μｍ厚のCo-Cr系磁性合金膜を形成した。[Example 1] Ar gas pressure 100 mTorr, power density 1.0 W applied to target
/ Cm ² , sputter rate 130 Å / min in oxygen atmosphere Co-Cr is sputtered under the sputter condition, and is deposited on the non-magnetic substrate.
A 0.20 μm thick Co—Cr based magnetic alloy film was formed.

このCo-Cr系合金薄膜型磁気デイスクの磁性層の組成を
調べるとCrが17原子％、Ｏが９．７原子％であり、膜面
内方向の保磁力は490エルステツド、角型比0.65であつ
て、又、結晶性のものではなく非晶質なものである。Examining the composition of the magnetic layer of this Co-Cr alloy thin film type magnetic disk, Cr was 17 atomic% and O was 9.7 atomic%, the coercive force in the in-plane direction was 490 oersteds, and the squareness ratio was 0.65. At the same time, it is not crystalline but amorphous.

次に、このCo-Cr系合金薄膜型磁気デイスク耐食性を調
べる為に、温度60℃、湿度90％の条件下に200時間放置
したが、ほとんど変化の認められないものであり、耐食
性に富むものであつた。Next, in order to investigate the corrosion resistance of this Co-Cr alloy thin film type magnetic disk, it was left for 200 hours under the conditions of temperature 60 ° C and humidity 90%, but there was almost no change and it was rich in corrosion resistance. It was.

又、孤立再生波形を調べると水平磁化膜固有の再生波形
である単峰性のものであり、そして浮上量0.25μｍのリ
ング型磁気ヘツドを用いての再生出力は１ｍＶＥあり、
再生出力の大きなものである。Moreover, when the isolated reproduction waveform is examined, it is a reproduction waveform peculiar to the horizontal magnetization film, which is a single peak, and the reproduction output using the ring type magnetic head having a flying height of 0.25 μm is 1 mVE.
It has a large playback output.

〔実施例２〕 Arガス圧150mTorr、ターゲツトに加える電力密度1.0Ｗ
／cm²、スパツタレート130Å／分の酸素雰囲気スパツタ
条件下でCo-Crをスパツタリングして、非磁性基体上に
0.20μｍ厚のCo-Cr系磁性合金膜を形成した。[Example 2] Ar gas pressure 150 mTorr, power density 1.0 W applied to target
/ Cm ² , sputter rate 130 Å / min in oxygen atmosphere Co-Cr is sputtered under the sputter condition, and is deposited on the non-magnetic substrate.
A 0.20 μm thick Co—Cr based magnetic alloy film was formed.

このCo-Cr系合金薄膜型磁気デイスクの磁性層の組成を
調べるとCrが15原子％、Ｏが14.1原子％であり、膜面内
方向の保磁力は510エルステツド、角型比0.50であつ
て、又、結晶性のものではなく非晶質なものである。Examining the composition of the magnetic layer of this Co-Cr alloy thin film magnetic disk, Cr was 15 atom%, O was 14.1 atom%, the coercive force in the in-plane direction was 510 Elsted, and the squareness ratio was 0.50. Also, it is not crystalline but amorphous.

次に、このCo-Cr系合金薄膜型磁気デイスクの耐食性
を、温度60℃、湿度90％の条件下に200時間放置して調
べたが、ほとんど変化の認められないものであり、耐食
性に富むものであつた。Next, the corrosion resistance of this Co-Cr alloy thin film type magnetic disk was examined by leaving it for 200 hours under the conditions of a temperature of 60 ° C and a humidity of 90%. Almost no change was observed and the corrosion resistance was excellent. It was a thing.

又、孤立再生波形を調べると水平磁化膜固有の再生波形
である単峰性のものであり、そして浮上量0.25μｍのリ
ング型磁気ヘツドを用いての再生出力は0.8ｍＶであ
り、再生出力の大きなものである。Also, when the isolated reproduction waveform is examined, it is a reproduction waveform peculiar to the horizontal magnetization film, and is a single peak, and the reproduction output using a ring type magnetic head with a flying height of 0.25 μm is 0.8 mV. It's a big one.

〔比較例１〕 Arガス圧40mTorr、ターゲツトに加える電力密度5.1Ｗ／
cm²、スパツタレート1700Å／分の酸素雰囲気スパツタ
条件下でCo-Crをスパツタリングして、非磁性基体上に
0.17μｍ厚のCo-Cr系磁性合金膜を形成した。[Comparative Example 1] Ar gas pressure 40 mTorr, power density 5.1 W / added to target
cm ² and sputter rate 1700 Å / min in oxygen atmosphere Sputtering Co-Cr under sputter conditions and depositing on non-magnetic substrate
A Co—Cr based magnetic alloy film having a thickness of 0.17 μm was formed.

このCo-Cr系合金薄膜型磁気デイスクの磁性層の組成を
調べるとCrが19原子％、Ｏが２．８原子％であり、膜面
内方向の保磁力は300エルステツド、角型比は0.32であ
つて、又、hcp構造のものであつて非晶質ではない。Examining the composition of the magnetic layer of this Co-Cr alloy thin film type magnetic disk, Cr is 19 at%, O is 2.8 at%, the coercive force in the in-plane direction is 300 Elsted, and the squareness ratio is 0.32. Moreover, it has an hcp structure and is not amorphous.

そして、この磁気デイスクは前記実施例のものと同様耐
食性には富むものの、孤立再生波形を調べると垂直磁化
膜固有の双峰性のものであり、又、浮上量0.25μｍのリ
ング型磁気ヘツドを用いての再生出力は0.4ｍＶにすぎ
ず、再生出力の小さなものである。Although this magnetic disk has a high corrosion resistance similar to that of the above-mentioned embodiment, it is a bimodal one peculiar to the perpendicular magnetization film when the isolated reproduction waveform is examined, and a ring type magnetic head having a flying height of 0.25 μm is used. The reproduction output used is only 0.4 mV, which is a small reproduction output.

又、上記実施例１、実施例２、及び比較例１のＣｏ−Ｃ
ｒ系合金膜について、酸素含有量と保磁力Ｈｃとの関係
を第１図に、酸素含有量と角型比Ｒｓとの関係を第２図
に、酸素含有量とリング型ヘッドの再生出力との関係を
第３図に示した。In addition, the Co-C of the above-mentioned Examples 1, 2 and Comparative Example 1
Regarding the r-based alloy film, the relationship between the oxygen content and the coercive force Hc is shown in FIG. 1, the relationship between the oxygen content and the squareness ratio Rs is shown in FIG. 2, and the oxygen content and the reproduction output of the ring head are shown. The relationship is shown in FIG.

この第１図から、Ｃｏ−Ｃｒ系合金膜中の酸素含有量が
増加するにつれて保磁力Ｈｃは高まるものの、１５原子
％程度で飽和の傾向を示していることが判る。すなわ
ち、酸素含有量が１４．１原子％より少ない範囲では高
Ｈｃの磁気記録媒体を得ることのできるものである。It can be seen from FIG. 1 that although the coercive force Hc increases as the oxygen content in the Co—Cr alloy film increases, the coercive force Hc shows a saturation tendency at about 15 atomic%. That is, a magnetic recording medium with high Hc can be obtained when the oxygen content is less than 14.1 atomic%.

又、第２図からはＣｏ−Ｃｒ系合金膜中の酸素含有量が
１０原子％程度をピークにして高い角型比Ｒｓを示して
いることが判り、特に酸素原子が９．７〜１４．１原子
％の範囲内のものでは高い角型比Ｒｓが得られている。Further, it can be seen from FIG. 2 that the oxygen content in the Co—Cr based alloy film shows a high squareness ratio Rs with a peak at about 10 atomic%, and in particular, oxygen atoms contain 9.7 to 14. A high squareness ratio Rs is obtained within the range of 1 atomic%.

さらに、第３図からはＣｏ−Ｃｒ系合金膜中の酸素含有
量が１０原子％程度をピークにして再生出力の高いこと
は判る。すなわち、リング型ヘッドによる再生にあって
は、磁気記録媒体は水平方向（膜面内方向）の保磁力Ｈ
ｃや角型比Ｒｓは高い方が好ましいものであり、このこ
ととも一致した傾向を示していることが判る。つまり、
酸素原子が９．７〜１４．１原子％の範囲内のものでは
高い再生出力が得られるのである。Further, it can be seen from FIG. 3 that the reproduction output is high with the oxygen content in the Co—Cr alloy film peaking at about 10 atomic%. That is, in reproducing by the ring type head, the magnetic recording medium has a coercive force H in the horizontal direction (in-plane direction).
It is understood that the higher the c and the squareness ratio Rs, the more preferable, and the tendency is in agreement with this. That is,
When the oxygen atom is in the range of 9.7 to 14.1 atomic%, a high reproduction output can be obtained.

そして、酸素原子が９．７〜１４．１原子％の範囲内の
ものにあっては、保磁力Ｈｃが４９００ｅ以上であっ
て、角型比Ｒｓが０．５以上であり、リング型ヘッドに
よる再生出力は８０ｍＶ以上の高い値を示しており、波
形は単峰パルスである。When the oxygen atoms are in the range of 9.7 to 14.1 atom%, the coercive force Hc is 4900e or more, the squareness ratio Rs is 0.5 or more, and the ring type head is used. The reproduction output shows a high value of 80 mV or more, and the waveform is a unimodal pulse.

尚、酸素原子が９．７〜１４．１原子％の範囲内のもの
が好ましい特長を呈するのは、酸素含有による非晶質化
によって、Ｃｏ−Ｃｒ系合金膜における水平方向の磁気
異方性が高まるからと思われる。It is to be noted that the oxygen-atom in the range of 9.7 to 14.1 atomic% is preferable because the amorphization due to the oxygen content causes a horizontal magnetic anisotropy in the Co—Cr alloy film. Is likely to increase.

〔効果〕〔effect〕

耐食性に富み、又、再生出力の大きなものである。 It is highly corrosion resistant and has a large reproduction output.

【図面の簡単な説明】[Brief description of drawings]

第１図はＣｏ−Ｃｒ系合金膜における酸素含有量と保磁
力Ｈｃとの関係を示すグラフ、第２図はＣｏ−Ｃｒ系合
金膜における酸素含有量と角型比Ｒｓとの関係を示すグ
ラフ、第３図はＣｏ−Ｃｒ系合金膜における酸素含有量
とリング型ヘッドの再生出力との関係を示すグラフであ
る。FIG. 1 is a graph showing the relationship between the oxygen content in the Co—Cr alloy film and the coercive force Hc, and FIG. 2 is a graph showing the relationship between the oxygen content in the Co—Cr alloy film and the squareness ratio Rs. FIG. 3 is a graph showing the relationship between the oxygen content in the Co—Cr alloy film and the reproduction output of the ring head.

Claims (1)

【特許請求の範囲】[Claims] 【請求項１】酸素原子を９．７〜１４．１原子％含むＣ
ｏ−Ｃｒ系非晶質合金磁性膜を非磁性基体上に設けたこ
とを特徴とする磁気記録媒体。1. C containing 9.7 to 14.1 atomic% of oxygen atom
A magnetic recording medium comprising an o-Cr amorphous alloy magnetic film provided on a non-magnetic substrate.