It is an object of the present disclosure to improve preservation stability of a magnetic recording medium including a magnetic powder having a small average particle volume.

The present disclosure provides a tape-shaped magnetic recording medium, including: a base; and a magnetic layer that is provided on the base and contains a magnetic powder, in which an average particle volume V of the magnetic powder is 2,000 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/k.sub.BT of the magnetic recording medium is 60 or more, and a ratio Hrp/Hc1 of a residual coercive force Hrp of the magnetic recording medium measured using a pulsed magnetic field to a coercive force Hc1 of the magnetic recording medium in a perpendicular direction is 2.10 or less.

The magnetic tape includes a non-magnetic support; and a magnetic layer, in which the magnetic layer has a timing-based servo pattern, an edge shape of the timing-based servo pattern, specified by magnetic force microscopy is a shape in which a difference L.sub.99.9−L.sub.0.1 between a value L.sub.99.9 of a cumulative distribution function of 99.9% and a value L.sub.0.1 of a cumulative distribution function of 0.1% in a position deviation width from an ideal shape of the magnetic tape in a longitudinal direction is 180 nm or less, and an absolute value ΔN of a difference between a refractive index Nxy of the magnetic layer, measured in an in-plane direction and a refractive index Nz of the magnetic layer, measured in a thickness direction is 0.25 or more and 0.40 or less.

Provided are a magnetic tape including: a non-magnetic support; and a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic support, in which a total thickness of the magnetic tape is equal to or smaller than 5.30 μm, the magnetic layer has a servo pattern, a center line average surface roughness Ra measured on a surface of the magnetic layer is equal to or smaller than 1.8 nm, and an absolute value ΔN of a difference between a refractive index Nxy of the magnetic layer, measured in an in-plane direction and a refractive index Nz of the magnetic layer, measured in a thickness direction is 0.25 to 0.40, a magnetic tape cartridge and a magnetic tape apparatus including this magnetic tape, a magnetic tape cartridge and a magnetic tape apparatus including this magnetic tape.

The magnetic tape includes a non-magnetic support and a magnetic layer, in which an edge shape of the timing-based servo pattern, specified by magnetic force microscopy is a shape in which a difference between a value L.sub.99.9 of a cumulative distribution function of 99.9% and a value L.sub.0.1 of a cumulative distribution function of 0.1% in a position deviation width from an ideal shape of the magnetic tape in a longitudinal direction is 180 nm or less, and in which a difference between a spacing S.sub.after measured on a surface of the magnetic layer by an optical interferometry after ethanol cleaning and a spacing S.sub.before measured on the surface of the magnetic layer by an optical interferometry before ethanol cleaning is greater than 0 nm and 6.0 nm or less.

The magnetic recording medium includes a non-magnetic support, and a magnetic layer including a ferromagnetic powder. The ferromagnetic powder is a ferromagnetic powder selected from the group consisting of a hexagonal strontium ferrite powder and an ε-iron oxide powder. The standard deviation of a height of the magnetic projection portion on a surface of the magnetic layer is in a range of 0.5 to 2.5 nm.

The magnetic recording medium includes a non-magnetic support, and a magnetic layer including a ferromagnetic powder. An anisotropic magnetic field Hk is 12 kOe or more, a center line average roughness Ra of the surface of the magnetic recording medium on the magnetic layer side is 1.2 nm or less, and a ratio θr of a contact angle θ2 with respect to 1-bromonaphthalene, measured on a surface on the magnetic layer side after a 1,1,1,2,2,3,4,5,5,5-decafluoropentane immersion, to a contact angle θ1 with respect to 1-bromonaphthalene, measured on the surface on the magnetic layer side before the 1,1,1,2,2,3,4,5,5,5-decafluoropentane immersion is 0.95 or less.

A magnetic tape in which a minimum value of TDStens among five TDStens measured respectively at a temperature of 16° C. and a relative humidity of 20%, a temperature of 16° C. and a relative humidity of 80%, a temperature of 26° C. and a relative humidity of 80%, a temperature of 32° C. and a relative humidity of 20% and a temperature of 32° C. and a relative humidity of 55% is 1.43 μm/N or more, a ratio of a change of TDStens to a change of a relative humidity obtained from the five TDStens is 0.005 μm/N/% or less, and a ratio of a change of TDStens to a change of a temperature obtained from the five TDStens is 0.020 μm/N/° C. or less.

A fractionation method for magnetic recording-magnetic powder is provided. The method includes applying a magnetic field to a liquid that contains magnetic recording-magnetic powder dispersed therein, wherein the liquid is stored in a storage unit relatively shifting a position where the magnetic field is applied to the liquid; and separating the storage unit into two parts after the shift.

A magnetic recording medium is provided and includes a substrate; and a magnetic layer provided over the substrate, wherein (wmax−wmin)/wmin≤400 [ppm] . . . (1) where wmax and wmin are respectively maximum and minimum of average values of width corresponding to samples of magnetic recording medium measured after the samples are stored for two hours under storage conditions (a loading tension in the longitudinal direction of the magnetic recording medium, a temperature and a relative humidity) for each of the samples, and a width of a sample of the magnetic recording medium at 25° C. and 50% relative humidity and without loading is ½ inch, magnetic recording medium has Young's modulus of less than 8.0 GPa in a longitudinal direction, and 4.0≤TB/(TA−TB) . . . (2) where TA is average thickness of magnetic recording medium and TB is average thickness of substrate.

[Object] Provided is a technology that is capable of further improving a recording density of data. [Solving Means] A magnetic recording medium according to the present technology is a magnetic recording medium in a shape of a tape that is long in a longitudinal direction and is short in a width direction, the medium including: a base material; a magnetic layer; and a non-magnetic layer that is provided between the base material and the magnetic layer, and contains one or more types of non-magnetic inorganic particles, in which the magnetic layer includes a data band long in the longitudinal direction in which a data signal is to be written, and a servo band long in the longitudinal direction in which a servo signal is written, and in the magnetic layer, a degree of vertical orientation is greater than or equal to 65%, a half width of a solitary waveform in a reproduction waveform of the servo signal is less than or equal to 195 nm, and a thickness of the magnetic layer is less than or equal to 90 nm, and the non-magnetic layer contains at least Fe-based non-magnetic particles as the non-magnetic inorganic particles, and in the non-magnetic layer, an average particle volume of the Fe-based non-magnetic particles is less than or equal to 2.0×10.sup.−5 μm.sup.3, and a thickness of the non-magnetic layer is less than or equal to 1.1 μm.