The magnetic tape includes a non-magnetic support; a magnetic layer including ferromagnetic powder and a binding agent on one surface side of the non-magnetic support; and a back coating layer including non-magnetic powder and a binding agent on the other surface side of the non-magnetic support, in which an isoelectric point of a surface zeta potential of the magnetic layer is equal to or smaller than 3.8, and an isoelectric point of a surface zeta potential of the back coating layer is equal to or smaller than 3.0, a magnetic tape cartridge, and a magnetic tape apparatus including this magnetic tape.

Provided are a magnetic recording medium including a non-magnetic support, and a magnetic layer including a ferromagnetic powder. The ferromagnetic powder is an ε-iron oxide powder, and an intensity ratio (Int1/Int2) of diffraction intensities obtained by an X-ray diffraction analysis of the magnetic layer using an In-Plane method is 1.0 or more and 6.5 or less; and a magnetic tape cartridge and a magnetic recording and reproducing device each including 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 0.04 μm to 0.08 μm, 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.

The magnetic tape includes a non-magnetic support; and a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic support, in which the magnetic layer has a servo pattern, and an absolute value ΔN of a difference between a refractive index Nxy measured regarding an in-plane direction of the magnetic layer and a refractive index Nz measured regarding a thickness direction of the magnetic layer is 0.25 to 0.40, 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 including ferromagnetic powder and a binding agent on the non-magnetic support, in which the magnetic layer has a servo pattern, and an absolute value ΔN of a difference between a refractive index Nxy measured regarding an in-plane direction of the magnetic layer and a refractive index Nz measured regarding a thickness direction of the magnetic layer is 0.25 to 0.40, a magnetic tape cartridge and a magnetic tape apparatus including this magnetic tape.

The magnetic recording medium includes a non-magnetic support; and a magnetic layer including a ferromagnetic powder, in which an isoelectric point of a surface zeta potential of the magnetic layer after pressing the magnetic layer at a pressure of 70 atm is equal to or greater than 5.5.

The magnetic recording medium includes: a non-magnetic support; and a non-magnetic layer including a non-magnetic powder and a magnetic layer including a ferromagnetic powder on the non-magnetic support in this order, in which a vertical squareness ratio is 0.70 to 1.00, a center line average roughness Ra measured regarding a surface of the magnetic layer with an atomic force microscope is equal to or smaller than 2.5 nm, and an interface variation rate between the magnetic layer and the non-magnetic layer in a cross section image obtained by imaging with a scanning electron microscope is equal to or less than 2.5%.

The magnetic recording medium includes a non-magnetic support; and a magnetic layer including a ferromagnetic powder, in which an isoelectric point of a surface zeta potential of the magnetic layer after pressing the magnetic layer at a pressure of 70 atm is equal to or less than 3.8.

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##

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 0.04 μm to 0.08 μm, 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.