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.5μm-PSDmag/PSD.sub.10μm-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.

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.5μm-PSDmag/PSD.sub.10μm-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.

The magnetic recording medium has a magnetic layer containing multiple nonmagnetic particles having a ratio, major axis length/minor axis length, of less than or equal to 1.5, the multiple nonmagnetic particles are present in the magnetic layer in a state where, when the depth to which each of the multiple nonmagnetic particles is embedded in the magnetic layer in observation of a sectional image picked up by SEM is denoted as b and the thickness of the magnetic layer as t, the average value of the ratio of b/t is less than or equal to 0.9, and the number of protrusions 5 nm or greater in height is 800 or greater and the number of protrusions 20 nm or greater in height is 20 or less as measured by AFM per an area 40 μm×40 μm on the magnetic layer side surface of the magnetic recording medium.

The magnetic recording medium has a magnetic layer containing multiple nonmagnetic particles having a ratio, major axis length/minor axis length, of less than or equal to 1.5, the multiple nonmagnetic particles are present in the magnetic layer in a state where, when the depth to which each of the multiple nonmagnetic particles is embedded in the magnetic layer in observation of a sectional image picked up by SEM is denoted as b and the thickness of the magnetic layer as t, the average value of the ratio of b/t is less than or equal to 0.9, and the number of protrusions 5 nm or greater in height is 800 or greater and the number of protrusions 20 nm or greater in height is 20 or less as measured by AFM per an area 40 μm×40 μm on the magnetic layer side surface of the magnetic recording medium.

Provided are a magnetic tape comprising a magnetic layer containing a ferromagnetic powder and a binding agent on a non-magnetic support, in which the magnetic layer contains an oxide abrasive, an average particle diameter of the oxide abrasive obtained from a secondary ion image acquired by irradiating a surface of the magnetic layer with a focused ion beam is greater than 0.08 μm and 0.14 μm or smaller, and an absolute value ΔN of a difference between a refractive index Nxy measured with respect to an in-plane direction of the magnetic layer and a refractive index Nz measured with respect to a thickness direction of the magnetic layer is 0.25 to 0.40, and a magnetic recording and reproducing device including the magnetic tape.

Two or more different recording currents are applied to a write coil of a recording head. A first of the two or more currents is a positive current and a second of the two or more currents is a negative current. In response to the application of the two or more different recording currents, a data stream is recorded to regions of a moving continuous magnetic recording medium such that each region has three or more magnetic states. The three or more magnetic states can be read from the continuous magnetic recording medium via a magnetic read transducer to recover the data stream.

A magnetic tape in which a tape thickness of the magnetic tape is 5.2 μm 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 tape in which a tape thickness of the magnetic tape is 5.2 μm or less, and in an environment with a temperature of 23° C. and a relative humidity of 50%, an AlFeSil abrasion value.sub.45° of a surface of the magnetic layer measured at a tilt angle of 45° of an AlFeSil prism is 20 μm to 50 μm, a standard deviation of an AlFeSil abrasion value of the surface of the magnetic layer measured at each of tilt angles of 0°, 15°, 30°, and 45° of the AlFeSil prism is 30 μm or less, and the tilt angle of the AlFeSil prism is an angle formed by a longitudinal direction of the AlFeSil prism and a width direction of the magnetic tape.

Methods for forming a multi-layered nanoscale structure by forming a stack of individual polymeric layers on a substrate are provided. Each individual polymeric layer comprises a cured polymeric material immobilizing a pattern of magnetic nanoparticles. The pattern of magnetic nanoparticles can be different within each individual polymeric layer due to their nature of formation.