The magnetic tape includes: a non-magnetic support; and a magnetic layer containing a ferromagnetic powder, in which a non-linear component of tape width deformation generated by storage for 10 days in an environment of a temperature of 60° C. and a relative humidity of 20% is 100 nm or less. A magnetic tape cartridge and a magnetic tape apparatus include the magnetic tape.

Provided is a magnetic recording medium capable of suppressing deterioration of running stability even after repeated recording or reproduction is performed.

The magnetic recording medium is a magnetic recording medium having a tape shape, and includes a substrate, an underlayer provided on one surface of the substrate and including a magnetic powder and a binder, and a magnetic layer provided on the underlayer and including a nonmagnetic powder and a binder. The magnetic recording medium has an average thickness of 5.3 μm or less. In a case where a correlation between an amount of projected particles and an erosion depth is obtained in each of the underlayer and the magnetic layer by a micro slurry-jet erosion (MSE), a calculation of a ratio of a particle amount required to wear an erosion depth range to the erosion depth range is performed in each of the underlayer and the magnetic layer on the basis of the correlation, and a result of the calculation is defined as an MSE resistance value of each of the underlayer and the magnetic layer, the ratio of the MSE resistance value of the magnetic layer to the MSE resistance value of the underlayer is in a range of 0.45 or more and 0.80 or less.

The magnetic recording medium includes a non-magnetic support, and a magnetic layer including a ferromagnetic powder. A magnetic tape cartridge and a magnetic recording and reproducing device include the magnetic recording medium. The ferromagnetic powder is an ε-iron oxide powder, and a ferromagnetic powder filling rate of a magnetic layer cross section obtained by observing a cross section of the magnetic layer with a scanning electron microscope is 0.60 or more and 0.80 or less.

The magnetic recording medium includes a non-magnetic support, and a magnetic layer including a ferromagnetic powder. A magnetic tape cartridge and a magnetic recording and reproducing device include the magnetic recording medium. The ferromagnetic powder is an ε-iron oxide powder, and a ferromagnetic powder filling rate of a magnetic layer surface obtained by observing a surface of the magnetic layer with a scanning electron microscope is 0.40 or more and 0.60 or less.

An object of the present invention is to provide a magnetic recording medium capable of suppressing a dimensional change in a width direction by setting the water vapor transmission rate within a specific range.

The present technology provides a magnetic recording medium having a tape shape, the magnetic recording medium including: a magnetic layer; a nonmagnetic layer; a base layer; and a back layer in this order, in which the magnetic layer and the nonmagnetic layer are in contact with each other, the nonmagnetic layer and the base layer are in contact with each other, an average thickness of the magnetic recording medium is 5.74 μm or less, a Young's modulus in an MD direction (longitudinal direction) of the base layer is 5.9 GPa or less, and a water vapor transmission rate of the magnetic recording medium, measured according to a Lyssy method, is 2.93 g/m.sup.2.Math.day or less. The Young's modulus in the MD direction of the base layer (longitudinal direction) is 5.3 GPa or less. A humidity expansion coefficient β at a temperature of 10° C. is 6.5 ppm/% RH or less.

The magnetic tape cartridge includes a magnetic tape, and a cartridge reel, in which, in the magnetic tape, a minimum winding deviation occurrence load measured after the magnetic tape is rewound around the cartridge reel by applying a tension of 0.20 N in a longitudinal direction of the magnetic tape is 200 N or less.

The magnetic tape includes: a non-magnetic support; and a magnetic layer containing a ferromagnetic powder, in which a non-linear component of a signal phase difference generated by storage for 10 days in an environment of a temperature of 60° C. and a relative humidity of 20% is 17.5 nm or less. A magnetic tape cartridge and a magnetic tape apparatus include the magnetic tape.

It is an object of the present technology to provide a magnetic recording medium that has a small total thickness and achieves excellent travelling stability. The present technology provides a tape-shaped magnetic recording medium including a magnetic layer, an underlayer, a base layer, and a back layer, in which a servo pattern is recorded in the magnetic layer, a statistical value σ.sub.SW indicating non-linearity of a servo band and being obtained from a reproduction waveform of a servo signal of the servo pattern is 24 nm or less, the base layer contains polyester as a main component, an average thickness t.sub.T of the magnetic recording medium is 5.6 μm or less, the magnetic recording medium contains a lubricant, pores are formed in the magnetic recording medium, and an average diameter of the pores of the magnetic recording medium that is measured in a state where the lubricant has been removed from the magnetic recording medium and the magnetic recording medium has been dried, is 6 nm or more and 11 nm or less.

The magnetic tape includes: a non-magnetic support; and a magnetic layer containing a ferromagnetic powder, and a magnetic tape cartridge and a magnetic tape apparatus include the magnetic tape. In a binarized image of a secondary electron image obtained by imaging a surface of the magnetic layer with a scanning electron microscope at an acceleration voltage of 5 kV, the number of bright regions having an equivalent circle diameter of 60 nm or more and less than 120 nm is 8000 or more and 30000 or less. Standard deviation σ of the number of the bright regions in a width direction of the surface of the magnetic layer is 2000 or less.

Provided are a magnetic recording medium including a non-magnetic support, and a magnetic layer including a ferromagnetic powder. The ferromagnetic powder is an ε-iron oxide powder, and an intensity ratio (Int1/Int2) of diffraction intensities obtained by an X-ray diffraction analysis of the magnetic layer using an In-Plane method is 1.0 or more and 6.5 or less; and a magnetic tape cartridge and a magnetic recording and reproducing device each including the magnetic recording medium.