| 摘要 |
PURPOSE:To obtain an optimum structure for a precise analog and digital recording, by partially annealing a paramagnetic tape with the laser beam, etc. to form a ferromagnetic region and a paramagnetic region within a sheet of paramagnetic alloy layer. CONSTITUTION:An alloy ingot of Fe-Co-Mn, etc. is heated to 1,100 deg.C for about an hour in an atmosphere and then hot rolled into a thin plate. This alloy ingot is furthermore subjected to a liquefying process for an hour at 1,000 deg.C in an H2 atmosphere and then a quenching in the water to remove an oxidized film to obtain a tape of about 20mu thickness after a cold rolling. A mechanical polishing is performed to this tape to obtain an uneven coarseness of <=0.5 on its single surface to obtain a paramagnetic alloy tape 1. Then an annealing is given entirely or partially to the tape 1 by means of a YAG laser device, etc. while giving a travelling to the tape 1 in a proper speed. In this case, the surface of the tape 1 is covered with the argon gas, and the other side of the surface is made in contact with a water-cooled metal to be cooled down. In such a way, a consecutive ferromagnetic layer 2 is formed into a belt or bit form with an even thickness (up to about 3mu). Thus an excellent magnetic tape is obtained without any drop-out or noise and with a high strength. |
