Magnetic tape with particular refractive index characteristics, magnetic tape cartridge, and magnetic tape apparatus

A magnetic tape cartridge comprising:

• a magnetic tape, which comprises:
• a non-magnetic support;
• and
• a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic support,
• wherein 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 apparatus comprising:

• a magnetic head;
• and
• a magnetic tape, which comprises:
• a non-magnetic support;
• and
• a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic support,
• wherein 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.