A magnetic recording medium includes a layer structure including a magnetic layer, a base layer, and a back layer in this order, in which an average thickness t.sub.T is t.sub.T≤5.5 μm, a dimensional variation Δw in a width direction to tension change in a longitudinal direction is 660 ppm/N≤Δw, and a surface roughness R.sub.abe of the base layer on a side of the back layer is 4.2 nm≤R.sub.abe≤8.5 nm.

Provided is a sputtering target containing 0.05 at % or more of Bi, and having a total content of metal oxides of from 10 vol % to 70 vol %, the balance containing at least Ru.

The magnetic recording medium includes a non-magnetic support; and a magnetic layer including a ferromagnetic powder, in which the ferromagnetic powder is a ferromagnetic powder selected from the group consisting of a hexagonal strontium ferrite powder and an ε-iron oxide powder, the number of recesses having a depth which is ⅓ or more of a minimum recording bit length existing on a surface of the magnetic layer is less than 10/10,000 μm.sup.2, and a ratio d/t.sub.mag of a value d which is ⅓ of the minimum recording bit length to a thickness t.sub.mag of the magnetic layer is 0.15 to 0.50.

The magnetic tape includes a non-magnetic support, and a magnetic layer including a ferromagnetic powder. A fluorine-containing compound is included in a portion on the non-magnetic support on a magnetic layer side, and a ratio θr of a water contact angle measured on a surface of the magnetic layer after sliding on a magnetic head to a water contact angle measured on the surface of the magnetic layer before sliding on the magnetic head is 0.70 or more.

A magnetic tape in which an edge weave amount of a tape edge on at least one side of the magnetic tape is 1.5 .Math.m or less, and in an environment with a temperature of 32° C. and a relative humidity of 80%, a frictional force F.sub.45° on the surface of the magnetic layer with respect to an LTO8 head measured at a head tilt angle of 45° is 4 gf to 15 gf, and a standard deviation of a frictional force F on the surface of the magnetic layer with respect to the LTO8 head measured at each of head tilt angles of 0°, 15°, 30°, and 45° is 10 gf or less.

The magnetic tape cartridge includes a magnetic tape that is accommodated in the magnetic tape cartridge while being wound around a reel hub. A water absorption amount of the magnetic tape measured after the magnetic tape cartridge is stored in a storage environment of a temperature of 32° C. and a relative humidity of 80% for 10 days is more than 0.30 g as a value in terms of a length of the magnetic tape of 1000 m, and the water absorption amount is a value measured in a measurement environment with a temperature of 21° C. and a relative humidity of 50% within 1 hour after the storage.

The magnetic tape cartridge includes a magnetic tape that is accommodated in the magnetic tape cartridge while being wound around a reel hub. A water absorption amount of the magnetic tape measured after the magnetic tape cartridge is stored in a storage environment of a temperature of 32° C. and a relative humidity of 80% for 10 days is 0.30 g or less as a value in terms of a length of the magnetic tape of 1000 m, and the water absorption amount is a value measured in a measurement environment with a temperature of 21° C. and a relative humidity of 50% within 1 hour after the storage.

A magnetic tape in which an arithmetic average roughness Ra measured at a surface of a magnetic layer with an atomic force microscope is 2.0 nm or less, and in an environment with a temperature of 32° C. and a relative humidity of 80%, a frictional force F.sub.45° on the surface of the magnetic layer with respect to an LTO8 head measured at a head tilt angle of 45° is 4 gf to 15 gf, and a standard deviation of a frictional force F on the surface of the magnetic layer with respect to the LTO8 head measured at each of head tilt angles of 0°, 15°, 30°, and 45° is 10 gf or less.

A magnetic tape in which a vertical switching field distribution SFD of the magnetic tape is 1.5 or less, and in an environment with a temperature of 32° C. and a relative humidity of 80%, a frictional force F.sub.45° on the surface of the magnetic layer with respect to an LTO8 head measured at a head tilt angle of 45° is 4 gf to 15 gf, and a standard deviation of a frictional force F on the surface of the magnetic layer with respect to the LTO8 head measured at each of head tilt angles of 0°, 15°, 30°, and 45° is 10 gf or less.

A magnetic recording medium includes: a substrate that is long in shape; and a magnetic layer containing magnetic powder and a binder. The glass transition point of the binder is not lower than 75° C. In a case where atomic force microscope observation images in a 10 μm×10 μm rectangular shape are acquired at five locations randomly selected from the surface on the side of the magnetic layer, any linear protrusion that is 3 nm to 20 nm in height, is 0.3 μm to 1.0 μm in width, and extends across two sides of the observation image does not exist in the observation images of four locations among the acquired observation images of the five locations.