A magnetic recording cartridge includes a magnetic recording medium of which an average thickness t.sub.T is t.sub.T5.6 m, a dimensional change amount w in a width direction with respect to a tension change in a longitudinal direction is 660 ppm/Nw, and a squareness ratio in a vertical direction is 65% or more, in which the magnetic recording medium is accommodated in a state of being wound around a reel and (a servo track width on an inner side of winding of the magnetic recording medium)(a servo track width on an outer side of winding of the magnetic recording medium)>0 is satisfied.

A magnetic recording cartridge is provided and including a magnetic recording medium, wherein an average thickness of the magnetic recording medium t.sub.T is 3.5 mt.sub.T 5.6 m, a dimensional change amount w in a width direction of the magnetic recording medium with respect to a tension change in a longitudinal direction of the magnetic recording medium is 700 ppm/Nw 20000 ppm, the magnetic recording medium is accommodated in a state of being wound around the reel in the cartridge case and (a servo track width on an inner side of winding of the magnetic recording medium)-(a servo track width on an outer side of winding of the magnetic recording medium) > is satisfied, and a squareness ratio measured in a vertical direction of the magnetic recording medium is 65% or more.

There is provided a magnetic recording medium which has a layer structure including a magnetic layer and a base layer, and of which an average thickness t.sub.T is t.sub.T5.6 m, a dimensional change amount w in a width direction with respect to a change in tension in a longitudinal direction is 660 ppm/Nw, a servo pattern is recorded on the magnetic layer, a standard deviation PES of a position error signal (PES) value obtained from a servo signal in which the servo pattern is reproduced is PES25 nm, and a maximum value .sub.1M of a friction coefficient .sub.1 between a surface on a side of the magnetic layer and an LTO3 head in a case where measurement of the friction coefficient .sub.1 is performed 250 times is 0.04.sub.1M0.5.

There is provided a magnetic recording medium which has a layer structure including a magnetic layer and a base layer, and of which an average thickness t.sub.T is t.sub.T5.6 m, a dimensional change amount w in a width direction with respect to a change in tension in a longitudinal direction is 660 ppm/Nw, a servo pattern is recorded on the magnetic layer, a standard deviation PES of a position error signal (PES) value obtained from a servo signal in which the servo pattern is reproduced is PES25 nm, and a maximum value .sub.1M of a friction coefficient .sub.1 between a surface on a side of the magnetic layer and an LTO3 head in a case where measurement of the friction coefficient .sub.1 is performed 250 times is 0.04.sub.1M0.5.

There is provided a magnetic recording medium of which an average thickness t.sub.T is t.sub.T5.6 , a dimensional change amount w in a width direction with respect to a change in tension in a longitudinal direction is 660 ppm/Nw, a squareness ratio in a vertical direction is 65% or more, and a width deformation coefficient b during long-term storage in a case where a long-term storage width change amount Y is defined as Y=blog(t) is 0.06 mb0.06 .

A magnetic recording medium is provided and includes a magnetic layer, a non-magnetic layer, a base layer and a back layer, wherein an average thickness t.sub.T of the magnetic recording medium is t.sub.T5.3 m, a dimensional change amount w in a width direction with respect to a change in tension in a longitudinal direction is 700 ppm/Nw, a thickness of the non-magnetic layer is 2.0 m or less, a squareness ratio measured in a vertical direction of the magnetic recording medium is 65% or more, and the magnetic layer includes a magnetic powder.

A magnetic recording cartridge includes a magnetic recording medium of which an average thickness t.sub.T is t.sub.T5.6 m, a dimensional change amount w in a width direction with respect to a tension change in a longitudinal direction is 660 ppm/Nw, and a squareness ratio in a vertical direction is 65% or more, in which the magnetic recording medium is accommodated in a state of being wound around a reel and (a servo track width on an inner side of winding of the magnetic recording medium)(a servo track width on an outer side of winding of the magnetic recording medium)>0 is satisfied.

A magnetic recording medium is provided that includes a recording layer structure including a first magnetic recording layer, a second magnetic recording layer, a third magnetic recording layer, a fourth magnetic recording layer, and a plurality of nonmagnetic exchange coupling layers. The first magnetic recording layer is closest to a substrate and the fourth magnetic recording layer is farthest from the substrate. An amount of Co in the first magnetic recording layer is greater than or equal to the amount of Co in the second magnetic recording layer, the third magnetic recording layer, and the fourth magnetic recording layer.

A magnetic recording medium is provided that includes a recording layer structure including a first magnetic recording layer, a second magnetic recording layer, a third magnetic recording layer, a fourth magnetic recording layer, and a plurality of nonmagnetic exchange coupling layers. The first magnetic recording layer is closest to a substrate and the fourth magnetic recording layer is farthest from the substrate. An amount of Co in the first magnetic recording layer is greater than or equal to the amount of Co in the second magnetic recording layer, the third magnetic recording layer, and the fourth magnetic recording layer.

A magnetic recording medium includes a layer structure including a magnetic layer, a non-magnetic layer, and a base layer in this order, in which an average thickness t.sub.T is t.sub.T5.5 m, a dimensional variation w in a width direction to tension change in a longitudinal direction is 660 ppm/Nw, and an average thickness t.sub.n of the non-magnetic layer is t.sub.n1.0 m.