| 摘要 |
PROBLEM TO BE SOLVED: To suppress fluidity of a recording film at the recording time and hence to prevent a thickness change of the film and to enhance reliability of data by adding an element having ferromagnetism into the recording film and also forming a ferromagnetic layer via an intermediate layer on the recording film. SOLUTION: A reflecting film 2, a recording film 3 of Ge2 , Sb2 and Te5 materials, a protective film 4, a reflecting film 5 and a magnetic film 6 of a ferromagnetic Co material are formed in a prescribed thickness and layered on a substrate 1 of a thickness of 0.6 mm respectively to form a discoid recording medium, and the magnetic layer 6 is residually magnetized in the vertical direction by a permanent magnet. Consequently, induced magnetization takes place in the recording layer of coexistence with ferromagnetic substance by a magnetic field of the magnetic layer, and a change of the film in thickness due to fluidity of the recording film in the recording layer by laser light is suppressed by constraint of magnetic Coulomb force. Therefore, fluctuation of a light quantity due to the thickness change of the film is suppressed to eliminate an error signal to be detected, so that the reliability of data is enhanced, and also rewriting durability is improved. For the ferromagnetic material, a transition elements and rare earth metal elements. etc., such as Fe and Sm as well as Ni and Co can be used. |
