| 摘要 |
PURPOSE:To obtain an alloy layer for a recording medium which has approximately specified sensitivity with the phase change of the aprt prradiated with laser light and wide latitude of variance in the stage of forming the recording layer, permits easy means production and has high C/N by using an alloy of In and Nb in a specific compsn. range as an optical recording medium. CONSTITUTION:The substrate 1 consisting of transparent plastic, etc. is placed on a freely rotatable holder in a vacuum vessel and an alloy of In and Nb or In and Nb alone are respectively used as target under the introduction of gaseous Ar so that the Ar ions are bombarded against the targets to induce sputtering. The alloy layer 2 consisting of 50-70wt% In and the balance Nb is formed to 500-1,000Angstrom thickness on the substrate 1 under rotation to form the recording layer. A protective layer 3 is provided of a synthetic resin on the layer 2 if necessary. A laser beam is irradiated from a laser light source of a recording system R on the recording medium D obtd. in the above-mentioned manner and the reflectivity of the irradiated part is increased by the phase change of the layer, by which recording is executed. The beam is irradiated from a laser light source 10 of a reproducing system P on the layer and the reading is executed by the reflected light thereof. Since the phase change is approximately constant in a wide range of the In-Nb compsn., the easy mass production of the recording medium D is made possible. |
