Fujifilm Corporation

Atsushi Morooka

Makoto Nagao

Toshio Tada

Satoshi Wakamatsu

Toshihide Ishioka

The magnetic recording medium has an arithmetic average roughness Ra of a surface of a magnetic layer is 2.2 nm or less, a fluorine concentration A obtained by X-ray photoelectron spectroscopy performed on a surface of the magnetic layer at a photoelectron take-off angle of 10 degrees being 5 atom % or more and 50 atom % or less, and B, which is calculated by Equation 1 from an integrated intensity Ftotal of fragments derived from a fluorine-containing compound obtained for an entire region in a thickness direction of a cross section of the magnetic layer by line profile analysis of TOF-SIMS and an integrated intensity Fupper of fragments derived from a fluorine compound obtained for a region from the surface of the magnetic layer to an intermediate thickness in the thickness direction of the cross section, being 60% or more and 95% or less, Equation 1:B=(Fupper/Ftotal)×100.

Magnetic recording medium, magnetic tape cartridge, and magnetic recording and reproducing device

Provided is a magnetic tape in which a vertical direction squareness ratio and/or a longitudinal direction squareness ratio obtained by measurement performed by sweeping an external magnetic field in the magnetic tape in a predetermined range by a vibrating sample magnetometer is 0.70 to 1.00, and A calculated by Expression 1 is equal to or smaller than 5.0%. In Expression 1, n represents the number of measurement points measured at magnetic field strength of &#x2212;40 kA/m to 40 kA/m during the sweeping and is 52, Mr(Hex) represents a magnetization quantity measured at magnetic field strength Hex, and &#x3bc; represents an arithmetical mean of Mr(Hex) obtained by measurement performed in the range of the magnetic field strength during the sweeping. 

Magnetic tape

The present invention provides a method of initializing a perpendicular magnetic recording medium in which a magnetic field having a magnetic field strength Hex is applied to a perpendicular magnetic recording medium having a magnetic layer having a coercive force Hc to initialize the magnetic layer, the method comprising the steps of: controlling a magnetic field strength HexP in a direction parallel to the medium surface of the magnetic field so that HexP&#x3e;1.3&#xd7;Hc; and controlling a magnetic field strength HexV in a direction perpendicular to the medium surface of the magnetic field so that HexV&#x3c;Hc.

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Minami-ashigara, Japan

Atsushi Morooka