The magnetic recording medium includes a non-magnetic support; and a magnetic layer including a ferromagnetic powder, in which the ferromagnetic powder is an ε-iron oxide powder having an average particle size of 9.0 nm to 20.0 nm, and in the ε-iron oxide powder, a content of particles having a particle size smaller than 8.0 nm is less than 20.0% by mass, a content of particles having a particle size smaller than 6.0 nm is less than 5.0% by mass, and a content of particles having a particle size greater than 25.0 nm is less than 20.0% by mass.

A tape-like magnetic recording medium includes a reinforced substrate, and a recording layer arranged on the reinforced substrate, and the reinforced substrate includes a substrate that has a first face and a second face opposed to each other, and has an average thickness of 4 μm or smaller, and a metal layer that contains cobalt, arranged on the first face, the reinforced substrate by itself causing thereon a depth of indentation of 0.25 μm or shallower, when a 0.7-mm-diameter hard sphere is impressed against the second face under 5.0 gf load for 10 seconds.

A hexagonal strontium ferrite powder, in which an average particle size is 10.0 to 25.0 nm, a content of one or more kinds of atom selected from the group consisting of a gallium atom, a scandium atom, an indium atom, and an antimony atom is 1.0 to 15.0 atom % with respect to 100.0 atom % of an iron atom, and a coercivity Hc is greater than 2,000 Oe and smaller than 4.000 Oe. A magnetic recording medium including: a non-magnetic support; and a magnetic layer including a ferromagnetic powder and a binding agent on the non-magnetic support, in which the ferromagnetic powder is the hexagonal strontium ferrite powder. A magnetic recording and reproducing apparatus including this magnetic recording medium.

The average thickness t.sub.T of a magnetic recording medium meets the requirement that t.sub.T≤5.5 [μm], and the dimensional change amount Δw 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/N≤Δw.

An object is to suppress or prevent a dimensional change of a magnetic recording tape.

The present technology provides a magnetic recording tape having a layer structure including a magnetic layer, a base layer, and a back layer in this order, in which a reinforcing layer containing a metal or a metal oxide is disposed on either a surface of the base layer on the magnetic layer side or a surface of the base layer on the back layer side, and a black area in an image obtained by binarizing an optical microscope image of a rectangular region of 64 μm×48 μm of the reinforcing layer is 300 μm.sup.2 or less. Furthermore, the present technology also provides a magnetic recording tape having a layer structure including a magnetic layer, a base layer, and a back layer in this order, in which a reinforcing layer containing a metal or a metal oxide is disposed on either a surface of the base layer on the magnetic layer side or a surface of the base layer on the back layer side, and the number of black regions in an image obtained by binarizing an optical microscope image of a rectangular region of 64 μm×48 μm of the reinforcing layer is 70 or less.

A magnetic recording medium according to the present technology includes: a base material; and a magnetic layer, in which the magnetic recording medium has a tape shape that is long in a longitudinal direction and short in a width direction, the magnetic layer includes a data band and a servo band, a data signal being written to the data band, the data band being long in the longitudinal direction, a servo signal being written to the servo data, the servo band being long in the longitudinal direction, the degree of perpendicular orientation of the magnetic layer being 65% or more, a full width at half maximum of an isolated waveform in a reproduced waveform of the servo signal is 195 nm or less, the magnetic layer has a thickness of 90 nm or less, and the base material has a thickness of 4.2 μm or less.

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.

In a magnetic recording medium, an average thickness t.sub.T is t.sub.T≤5.5 μm, a dimensional variation Δw in a width direction to tension change in a longitudinal direction is 650 ppm/N≤Δw, and a rate of shrinkage in the longitudinal direction is 0.08% or less.

The magnetic recording medium includes: a non-magnetic support; and a magnetic layer including ferromagnetic powder, in which the magnetic layer includes a compound having a salt structure, and the salt structure is an ammonium salt structure of an alkyl ester anion represented by the following Formula 1. In Formula 1, R represents an alkyl group having 7 or more carbon atoms or a fluorinated alkyl group having 7 or more carbon atoms, Z.sup.+ represents an ammonium cation, and a water contact angle on a surface of the magnetic layer is 80° or more and less than 100°. A magnetic recording and reproducing apparatus includes the magnetic recording medium. ##STR00001##

The magnetic recording medium 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 a difference between a spacing measured on a surface of the back coating layer by optical interferometry under a pressure of 0.5 atm after n-hexane cleaning and a spacing measured on the surface of the back coating layer by optical interferometry under a pressure of 13.5 atm after n-hexane cleaning is 12 nm or more.