VERTICAL MAGNETIC RECORDING MEDIUM

摘要

PURPOSE:To obtain an excellent recording and reproducing characteristic by forming the ''Permalloy'' film in a double layered film medium formed with the ''Permalloy'' film between a substrate consisting of a non-magnetic material and a Co-Cr vertically magnetized film into a multi-layered film construction. CONSTITUTION:A ''Permalloy'' film 10 of the three-layered construction wherein three layers of ''Permalloy'' films of 400Angstrom for each one layer are superposed via a Co-Cr vertically magnetized film having 0.1mum film thickness is disposed on a film substrate 8 consisting of a heat resistant high polymer material having 18mum film thickness. If a signal of 100 KFRPI is recorded and reproduced by a vertical head of an auxiliary magnetic pole excitation type in the two-layered film medium having such construction, a reproduction output higher by 20dB is obtd. as compared with a conventional medium coated with iron oxide contg. Co. A reproduction output higher by 6dB is obtd. as well with the two-layered film medium of the same construction except that the ''Permalloy'' film is of a single layered construction and has 1,200Angstrom film thicness.