Abstract: A defect inspection is performed for each of glass substrates by a surface defect detector. The distance from the center of the glass substrate to a detected defect, as a radius of a nonmagnetic region to be formed circular, is recorded along with an ID assigned to the glass substrate. Such defect information is recorded in a defect list using a printer or recorded in an RFID tag using an RFID writer. The defect list or the RFID tag is attached to a glass-substrate case. Each glass substrate and its defect information are in one-to-one correspondence and are provided to a customer as a magnetic disk manufacturer. Based on the obtained defect information, the customer manufactures magnetic disks each being a discrete track recording medium having the nonmagnetic region formed at the position where the defect is present.

Abstract: A defect inspection is performed for each of glass substrates by a surface defect detector. The distance from the center of the glass substrate to a detected defect, as a radius of a nonmagnetic region to be formed circular, is recorded along with an ID assigned to the glass substrate. Such defect information is recorded in a defect list using a printer or recorded in an RFID tag using an RFID writer. The defect list or the RFID tag is attached to a glass-substrate case. Each glass substrate and its defect information are in one-to-one correspondence and are provided to a customer as a magnetic disk manufacturer. Based on the obtained defect information, the customer manufactures magnetic disks each being a discrete track recording medium having the nonmagnetic region formed at the position where the defect is present.

Abstract: A defect inspection is performed for each of glass substrates by a surface defect detector. The distance from the center of the glass substrate to a detected defect, as a radius of a nonmagnetic region to be formed circular, is recorded along with an ID assigned to the glass substrate. Such defect information is recorded in a defect list using a printer or recorded in an RFID tag using an RFID writer. The defect list or the RFID tag is attached to a glass-substrate case. Each glass substrate and its defect information are in one-to-one correspondence and are provided to a customer as a magnetic disk manufacturer. Based on the obtained defect information, the customer manufactures magnetic disks each being a discrete track recording medium having the nonmagnetic region formed at the position where the defect is present.

Abstract: A defect inspection is performed for each of glass substrates by a surface defect detector. The distance from the center of the glass substrate to a detected defect, as a radius of a nonmagnetic region to be formed circular, is recorded along with an ID assigned to the glass substrate. Such defect information is recorded in a defect list using a printer or recorded in an RFID tag using an RFID writer. The defect list or the RFID tag is attached to a glass-substrate case. Each glass substrate and its defect information are in one-to-one correspondence and are provided to a customer as a magnetic disk manufacturer. Based on the obtained defect information, the customer manufactures magnetic disks each being a discrete track recording medium having the nonmagnetic region formed at the position where the defect is present.

Abstract: In a magnetic recording medium including a nonmagnetic substrate on which a magnetic layer, a protection film, and a lubricant film are successively stacked, the lubricant film is formed by quantitatively controlling an amount of a lubricant in consideration of a surface coverage ratio of the lubricant film relative to the protection film and an average thickness of the lubricant film. Preferably, the surface coverage ratio is selected between 0.55 and 0.985 while the average thickness is not smaller than 0.4 time an attenuation length of a photoelectron which is emitted from a predetermined element and which is attenuated in the lubricant film. To this end, an x-ray photoelectron spectroscopy is used to evaluate the lubricant film.

Abstract: There is provided a magnetic recording medium comprising a nonmagnetic substrate (10, 20), at least one magnetic layer (30) having an upper surface (30a), and a protection layer (40) made of zirconia and having an upper surface (40a). The upper surface (30a) has a surface roughness of 3 nm or smaller defined by maximum height (R.sub.max) while the upper surface (40a) has a surface roughness ranging from 5 nm to 60 nm. When a distance Zi indicates a degree of irregularities of the upper surface (40a) of the protection layer (40), a standard deviation of the heights Zi is 5.7 nm or smaller.

Abstract: In a magnetic recording medium including a nonmagnetic substrate on which a magnetic layer, a protection film, and a lubricant film are successively tacked, the lubricant film is formed by quantitatively controlling an amount of a lubricant in consideration of a surface coverage ratio of the lubricant film relative to the protection film and an average thickness of the lubricant film. Preferably, the surface coverage ratio is selected between 0.55 and 0.985 while the average thickness is not smaller than 0.4 time an attenuation length of a photoelectron which is emitted from a predetermined element and which is attenuated in the lubricant film. To this end, an X-ray photoelectron spectroscopy is used to evaluate the lubricant film.