Magnetic recording medium having a dimensional variation
摘要
說明書
The above-mentioned coercive force Hc is determined as follows. First, a measurement sample is cut out from the elongated magnetic recording medium 10, and the M-H loop for the entire measurement sample is measured in the thickness direction of the measurement sample (the thickness direction of the magnetic recording medium 10) with the use of a vibrating sample magnetometer (VSM). Next, the coating film (the base layer 12, the recording layer 13, and the like) is wiped with the use of acetone, ethanol, or the like, only the substrate 11 is left for background correction, and the M-H loop for the substrate 11 is measured in the thickness direction of the substrate 11 (the thickness direction of the magnetic recording medium 10) with the use of a VSM. Thereafter, the M-H loop for the substrate 11 is subtracted from the M-H loop for the entire measurement sample to obtain an M-H loop after the background correction. The coercive force Hc is determined from the obtained M-H loop. Note that the M-H loops are all measured at 25° C. Furthermore, in measuring the M-H loop in the thickness direction (vertical direction) of the magnetic recording medium 10, no “demagnetizing field correction” is performed.
(Ratio R Between Coercive Force Hc (50) and Coercive Force Hc (25))
