The magnetic tape satisfies TDSage+TDSenv−TC≤0.30 μm. TDSage is a maximum absolute value of a difference between the servo band interval obtained before a predetermined storage and the servo band interval obtained after the storage, TDSenv is a value calculated by multiplying a difference between a maximum value and a minimum value of the servo band interval respectively obtained under five predetermined environments by ½, TC is a value calculated by multiplying TDStens by 0.5 N, and TDStens is a ratio of a change in the servo band interval to a change in tension calculated from the servo band interval respectively obtained under five predetermined environments by applying a plurality of different tensions in the longitudinal direction of the magnetic tape.

In the magnetic recording medium, a number distribution A of a plurality of bright regions, based on equivalent circle diameters thereof, in a binarized image of a secondary electron image obtained by imaging a surface of the magnetic layer by a scanning electron microscope at an acceleration voltage of 5 kV and a number distribution B of a plurality of dark regions, based on equivalent circle diameters thereof, in a binarized image of a secondary electron image obtained by imaging a surface of the magnetic layer by a scanning electron microscope at an acceleration voltage of 2 kV respectively satisfy a predetermined number distribution.

The present disclosure provides where a magnetic recording medium is provided and includes a base; an underlayer that is provided over the base and includes a non-magnetic powder; and a magnetic layer that is provided over the underlayer and includes a magnetic powder and a binder, wherein an average particle volume V of the magnetic powder is 1600 nm.sup.3 or less, an average thickness of the magnetic recording medium is 5.3 μm or less, a thermal stability K.sub.uV.sub.act/k.sub.BT of the magnetic recording medium is 63 or more, and a ratio Hrp/Hc1 of a residual coercive force Hrp of the magnetic recording medium measured using a pulsed magnetic field in a perpendicular direction to a coercive force Hc1 of the magnetic recording medium in the perpendicular direction is 1.98 or less.

A tape-shaped magnetic recording medium includes a base, a nonmagnetic layer that is provided on the base and contains a nonmagnetic powder, and a magnetic layer that is provided on the nonmagnetic layer and contains a magnetic powder. In the magnetic recording medium, the magnetic layer has an average thickness of not more than 90 nm, the magnetic powder has an average aspect ratio of from 1.0 to 3.0, a coercive force Hc1 in a perpendicular direction is not more than 3,000 Oe, the coercive force Hc1 in the perpendicular direction and a coercive force Hc2 in a longitudinal direction satisfy the relation of Hc2/Hc1≤0.8, the nonmagnetic layer has an average thickness of not more than 1.1 μm, and the nonmagnetic powder has an average particle volume of not more than 2.0×10.sup.−5 μm.sup.3.

The magnetic recording medium includes: a non-magnetic support; and a magnetic layer including ferromagnetic powder, in which a difference (S.sub.0.5−S.sub.13.5) between a spacing S.sub.0.5 measured on a surface of the magnetic layer by optical interferometry after n-hexane cleaning under a pressure of 0.5 atm and a spacing S.sub.13.5 measured on the surface of the magnetic layer by optical interferometry after n-hexane cleaning under a pressure of 13.5 atm is 9.0 nm or more.

The magnetic tape includes a non-magnetic support, a magnetic layer that includes ferromagnetic powder having an average particle volume of 2,500 nm.sup.3 or less on one surface side of the non-magnetic support, and a back coating layer that includes non-magnetic powder on the other surface side of the non-magnetic support, in which the ferromagnetic powder is ferromagnetic powder selected from the group consisting of hexagonal ferrite powder and ε-iron oxide powder, and a ratio (PSD.sub.5 μm-PSDmag/PSD.sub.10 μm-PSDbc) of the magnetic layer and the back coating layer is in a range of 0.0050 to 0.20. A magnetic tape cartridge and a magnetic recording and reproducing apparatus include the magnetic tape.

In the magnetic tape cartridge, a tape has a tape thickness of 5.3 μm or less, and a difference W.sub.inner−W.sub.outer between a tape width W.sub.inner at a position of 50 m±1 m from a tape inner end and a tape width W.sub.outer at a position of 50 m±1 m from a tape outer end is 4.1 μm to 19.9 μm as a value measured on 100th day from a date of magnetic tape cartridge manufacture, and a difference G.sub.inner−G.sub.outer between a servo band interval G.sub.inner in a range of 49 m to 51 m from the tape inner end and a servo band interval G.sub.outer in a range of 49 m to 51 m from the tape outer end is −3.9 μm to 0.0 μm as a value measured on 100th day from the date of magnetic tape cartridge manufacture.

In the probability distribution calculated from TDSage, TDSenv, and TC, the magnetic tape has the probability P.sub.fail of equal to or less than 0.2%, in which the absolute value of ΔSB exceeds 0.3 μm. TDSage is a maximum absolute value of a difference between the servo band interval obtained before a predetermined storage and the servo band interval obtained after the storage, TDSenv is a value calculated by multiplying a difference between a maximum value and a minimum value of the servo band interval respectively obtained under five predetermined environments by ½, TC is a value calculated by multiplying TDStens by 0.5 N, and TDStens is a ratio of a change in the servo band interval to a change in tension calculated from the servo band interval respectively obtained under five predetermined environments by applying a plurality of different tensions in the longitudinal direction of the magnetic tape.

To provide a servo signal verifying device for verifying a servo signal of a magnetic recording tape with high recording density. The present technology provides a servo signal verifying device including: at least one servo signal reading head that reads a servo signal written to a servo band of a magnetic recording tape; a first amplifier that amplifies the servo signal read by the servo signal reading head; and a second amplifier that includes a low-pass filter with a cutoff frequency of 35 MHz or less and amplifies a signal amplified by the first amplifier. Further, the present technology provides also a servo writer that includes the servo signal verifying device, and a method of producing a magnetic recording tape using the servo signal verifying device. Further, the present technology provides also a servo signal reading head constituting the servo signal verifying device.

The magnetic tape includes a non-magnetic support and a magnetic layer including a ferromagnetic powder, in which in an environment of a temperature of 23° C. and a relative humidity of 50%, an AlFeSil abrasion value.sub.0.2 N on a magnetic layer surface, which is measured by applying a tension of 0.2 N in a longitudinal direction of the magnetic tape, is in a range of 20 to 50 μm, and an AlFeSil abrasion value.sub.1.5 N on the magnetic layer surface measured by applying a tension of 1.5 N in the longitudinal direction of the magnetic tape is in a range of 20 to 50 μm.