A magnetic recording medium is provided and 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 of the magnetic recording medium is 3.5 mt.sub.T5.3 m, a dimensional variation w in a width direction of the magnetic recording medium to tension change in a longitudinal direction of the magnetic recording medium is 700 ppm/Nw2000 ppm/N, and an average thickness t.sub.n of the non-magnetic layer is t.sub.n1.0 m.

[Object] To provide technologies such as an orientation device capable of increasing strength of a magnetic field in a transport path.

[Solving Means] An orientation device according to the present technology includes a transport path, a permanent magnet portion, and a yoke portion. The transport path allows a base on which a magnetic coating film containing magnetic powder has been formed to pass through the transport path along a transport direction. The permanent magnet portion includes a plurality of first permanent magnets, and a plurality of second permanent magnets that is opposed to the plurality of first permanent magnets across the transport path in a vertical direction that is vertical to the transport direction in a manner that opposite poles face each other, the permanent magnet portion vertically orienting particles of the magnetic powder by applying a magnetic field to the magnetic coating film on the base that passes through the transport path. The yoke portion is made of a soft magnetic material, and connects to poles on a side opposite to the transport path side of the plurality of first permanent magnets, and to poles on a side opposite to the transport path side of the plurality of second permanent magnets.

The average thickness t.sub.T of a magnetic recording medium meets the requirement that t.sub.T5.5 [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.

A refractive index nL and an attenuation rate kL of a magnetic layer are obtained by irradiating linearly polarized light at an irradiation angle of 70 from a lengthwise direction of the magnetic layer to the surface of the magnetic layer, and a vertical reflectance RL during vertical incidence of the linearly polarized light in the lengthwise direction is obtained based on nL and kL. A refractive index nT and an attenuation rate kT of the magnetic layer are obtained by irradiating linearly polarized light at an irradiation angle of 70 from a width direction of the magnetic layer to the surface of the magnetic layer, and a vertical reflectance RT during vertical incidence of the linearly polarized light in the width direction is obtained from nT and kT. If a variation rate A (%) of RL and RT is A=|RL/RT1|100, the relationship A10% is established.

A refractive index nL and an attenuation rate kL of a magnetic layer are obtained by irradiating linearly polarized light at an irradiation angle of 70 from a lengthwise direction of the magnetic layer to the surface of the magnetic layer, and a vertical reflectance RL during vertical incidence of the linearly polarized light in the lengthwise direction is obtained based on nL and kL. A refractive index nT and an attenuation rate kT of the magnetic layer are obtained by irradiating linearly polarized light at an irradiation angle of 70 from a width direction of the magnetic layer to the surface of the magnetic layer, and a vertical reflectance RT during vertical incidence of the linearly polarized light in the width direction is obtained from nT and kT. If a variation rate A (%) of RL and RT is A=|RL/RT1|100, the relationship A10% is established.

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.

A data storage device is disclosed comprising a disk surface comprising a magnetic recording layer comprising a first magnetic material having a first coercivity intermixed with a second magnet material having a second coercivity higher than the first coercivity, and a head comprising a write coil configured to magnetize the magnetic recording layer in order to write data to the disk surface. The data is written to the disk surface by configuring the magnetic recording layer into one of at least three recording states, and the data is read from the disk surface by reading the magnetic recording layer using the head to generate a multi-level read signal, where each level of the read signal corresponds to one of the recording states.

A data storage device is disclosed comprising a disk surface comprising a magnetic recording layer comprising a first magnetic material having a first coercivity intermixed with a second magnet material having a second coercivity higher than the first coercivity, and a head comprising a write coil configured to magnetize the magnetic recording layer in order to write data to the disk surface. The data is written to the disk surface by configuring the magnetic recording layer into one of at least three recording states, and the data is read from the disk surface by reading the magnetic recording layer using the head to generate a multi-level read signal, where each level of the read signal corresponds to one of the recording states.

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.

The magnetic tape includes: a non-magnetic support; a magnetic layer that includes ferromagnetic powder 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 strontium ferrite powder and -iron oxide powder, and the number of protrusions having a height of 50 nm or more and less than 75 nm on a surface of the back coating layer is 700 pieces/6400 m.sup.2 or less.