An apparatus includes a first magnetic layer. A second magnetic layer overlies the first magnetic layer and is magnetically softer than the first magnetic layer. An exchange control layer is between the first magnetic layer and the second magnetic layer. The includes a higher Ms (saturation magnetization) than the first magnetic layer at room temperature.

Provided is a magnetic recording medium having a recording track width of 2 m or less, including: a recording layer containing a powder of particles containing iron oxide, in which a squareness ratio measured in a transport direction is 30% or less, a squareness ratio S1 measured in the transport direction and a squareness ratio S2 measured in a width direction satisfy a relationship S1S2, a coercive force is 220 kA/m or greater and 310 kA/m or less, an activation volume is 8000 nm.sup.3 or less, and in a switching field distribution (SFD) curve, a peak ratio X/Y of a main peak height X and a height Y of a sub-peak near zero magnetic field is 3.0 or greater.

Provided is a magnetic recording medium having a recording track width of 2 m or less, including: a recording layer containing a powder of particles containing iron oxide, in which a squareness ratio measured in a transport direction is 30% or less, a squareness ratio S1 measured in the transport direction and a squareness ratio S2 measured in a width direction satisfy a relationship S1S2, a coercive force is 220 kA/m or greater and 310 kA/m or less, an activation volume is 8000 nm.sup.3 or less, and in a switching field distribution (SFD) curve, a peak ratio X/Y of a main peak height X and a height Y of a sub-peak near zero magnetic field is 3.0 or greater.

A magnetic recording medium includes: a flexible and elongated substrate; a soft magnetic layer having an average thickness of 10 nm or more to 50 nm or less; and a recording layer, in which the soft magnetic layer is disposed between the substrate and the recording layer, and a difference in Young's modulus between the magnetic recording medium and the substrate in a longitudinal direction of the substrate is 2.4 GPa or more.

A magnetic recording medium includes: a flexible and elongated substrate; a soft magnetic layer having an average thickness of 10 nm or more to 50 nm or less; and a recording layer, in which the soft magnetic layer is disposed between the substrate and the recording layer, and a difference in Young's modulus between the magnetic recording medium and the substrate in a longitudinal direction of the substrate is 2.4 GPa or more.

A magnetic recording medium has a recording surface having an average surface roughness SRa of 3.0 nm or less, the number of projections having a height of 7.5 nm or more included in a unit region (where the unit region is a square region with each side having a length of 30 m) of the recording surface is 256 or more, and the number of projections having a height of 15 nm or more included in the unit region of the recording surface is 0 or more and 104 or less.

A magnetic recording medium has a recording surface having an average surface roughness SRa of 3.0 nm or less, the number of projections having a height of 7.5 nm or more included in a unit region (where the unit region is a square region with each side having a length of 30 m) of the recording surface is 256 or more, and the number of projections having a height of 15 nm or more included in the unit region of the recording surface is 0 or more and 104 or less.

A magnetic recording medium includes a long-shaped base substrate having flexibility, a soft magnetic layer, and a magnetic recording layer. A squareness ratio in a longitudinal direction of the base substrate is equal to or less than a squareness ratio in a short-side direction of the base substrate. The squareness ratio in the longitudinal direction of the base substrate is 30% or less.

A magnetic recording medium includes a long-shaped base substrate having flexibility, a soft magnetic layer, and a magnetic recording layer. A squareness ratio in a longitudinal direction of the base substrate is equal to or less than a squareness ratio in a short-side direction of the base substrate. The squareness ratio in the longitudinal direction of the base substrate is 30% or less.

The average thickness t.sub.T of a magnetic recording medium meets the requirement that t.sub.T 5.5 [m], and the dimensional change amount w in the width direction of the magnetic recording medium with respect to the tension change in the longitudinal direction of the magnetic recording medium meets the requirement that 700 ppm/Nw.