JPS62128043A - magneto-optical recording material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a magneto-optical recording material that records information thermomagnetically and reproduces it magneto-optically.

BACKGROUND OF THE INVENTION Magneto-optical recording materials are high-density recording materials that can be recorded and erased, and are expected to have a wide range of applications in the information society in recent years. The main conventional magneto-optical recording materials are TbFe and GdTb.
Rare earth metals such as Fe, TbFeCo, etc.
It is a transition metal-based amorphous alloy film,
, this amorphous alloy film has uniaxial magnetic anisotropy in the direction perpendicular to the film surface.

Recording and reproduction on such a magneto-optical recording material are carried out as follows. For example, the alloy film is locally heated by a laser beam to a high temperature above the compensation temperature or above the Curie temperature. By applying an external magnetic field perpendicular to the film surface,
Recording is performed by magnetizing the heated region of the film in a desired direction perpendicular to the film surface. For reproduction, a linearly polarized beam is irradiated onto the alloy film surface.
This is done by detecting the magnetization direction of that region using the Faraday effect or Kerr effect.

Problems to be Solved by the Invention However, the rare earth metal-transition metal based magneto-optical recording material is susceptible to corrosion and oxidation, and its thin film is heated at 80°C and 80°C.
Under high temperature and high humidity conditions of 0% RH, corrosion occurs within a few days and the film becomes unusable as a recording film.

In view of the above problems, the present invention provides a highly reliable, long-life magneto-optical recording material with excellent corrosion resistance and oxidation resistance.

Means for Solving the Problems In order to achieve this object, the magneto-optical recording material of the present invention contains at least one element selected from phosphorus, carbon, boron, and silicon in the rare earth metal-transition metal alloy; The material composition includes at least one element selected from copper, titanium, zirconium, molybdenum, and tungsten.

For production This material composition allows for phosphorus, carbon, and boron.

The interaction between semimetals such as silicon and metals such as titanium, zirconium, molybdenum, and tungsten promotes passivation of transition metals, stabilizing the entire alloy film and providing excellent corrosion and oxidation resistance. A magneto-optical recording material can be realized.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings. The sample of this example is an amorphous material consisting of at least one element selected from gadolinium, terbium, iron, phosphorus, carbon, boron, and silicon, and at least one element selected from titanium, zirconium, molybdenum, and tungsten. It is an alloy film and was produced by sputtering method. After making the inside of the sputtering equipment a vacuum with a pressure of 10-6 Torr or less, high-purity argon was introduced into the equipment to create a 6×1 O-
Sputtering was performed at a pressure of 67 orr to produce an alloy film with a thickness of 60 to 1100 nm on a glass substrate.

The composition of the alloy film thus produced was as follows.

(Gd0.13Tb0.13"0.74) 1-Y
-ZMYDZ (where M is at least one element among copper, titanium, zirconium, molybdenum, and tungsten, D is at least one element among carbon, boron, and silicon, and Y is 0 to 0. 16.Z is 0 to 0.3
It is. ) Its characteristics will be explained below.

FIG. 1 shows the corrosion rate of the alloy film according to the present invention when the metal element represented by M in the composition formula of the alloy film is changed.
The comparison is made with the conventional alloy film as 1, and 3
This is the result in saline solution.

Copper has the greatest effect on improving corrosion resistance, followed by titanium,
Zirconium, molybdenum, and tungsten are the most important in that order, and corrosion resistance is improved by more than an order of magnitude compared to conventional materials. FIG. 2 shows the corrosion rate of the alloy film according to the present invention when the semimetal element represented by D in the formula of the alloy film is changed, with the conventional alloy film being 1, and 3 % saline solution. The addition of phosphorus, carbon, boron, and silicon
It greatly contributes to improving corrosion resistance.

In this example, the transition metal is iron, and the rare earth metals are gadolinium and terbium. However, the transition metal is at least one of cobalt, nickel, and iron, and the rare earth metal is at least one of gadolinium, terbium, and dysprosium. There may be.

Effects of the Invention The present invention provides a rare earth metal-transition metal based magneto-optical recording material containing at least one element selected from copper, titanium, molybdenum, and tungsten and at least one element selected from phosphorus, carbon, boron, and silicon. By adding it, it is possible to promote passivation of the transition metal and realize a magneto-optical recording material with excellent corrosion resistance and oxidation resistance.

[Brief explanation of drawings]

FIG. 1 is a characteristic diagram showing the relationship between the corrosion rate of the magneto-optical recording material and the concentration of the added metal element in one embodiment of the present invention, and FIG.
The figure is a characteristic diagram showing the relationship between the corrosion rate and the concentration of the added metalloid element in the magneto-optical recording material of this example.

Claims (2)

[Claims] (1) Consisting of an amorphous alloy layer of rare earth metal-transition metal,
The amorphous alloy layer has a general formula (R_VT_1_-_V)_XM_YD_Z (wherein, R
is at least one element from the rare earth metal group, T is at least one element from the transition metal group, M is copper, titanium,
At least one element among zirconium, molybdenum, and tungsten, D represents at least one element among phosphorus, carbon, boron, and silicon, and V is 0.1<V<0.
．． 4, Y is 0.001<Y<0.15, Z is 0.001
<Z<0.3, X is 1-Y-Z). (2) Magneto-optical according to claim 1, characterized in that R is at least one element among gadolinium, terbium, and dysprosium, and T is at least one element among iron, cobalt, and nickel. Recording materials.