Magnetic recording medium

A magnetic recording medium comprising:

• a non-magnetic substrate;
• a non-magnetic layer formed on one of principal surfaces of the non-magnetic substrate;
• and a magnetic layer formed on a principal surface of the non-magnetic layer opposite to the non-magnetic substrate,
• wherein the magnetic layer contains a magnetic powder,
• the magnetic powder is a hexagonal strontium ferrite magnetic powder,
• Mr and t satisfy 0.0020 μT·m≤Mr·t≤0.0150 μT·m, where Mr is the residual magnetic flux density of the magnetic layer, and t is the average thickness of the magnetic layer,
• L1 satisfies 2 nm≤L1≤6 nm, where L1 is the average thickness of a first mixed layer that is formed on the surface of the magnetic layer opposite to the non-magnetic layer,
• L2 satisfies 0.1≤L2/t≤0.45, where L2 is the average thickness of a second mixed layer that is formed on the surface of the magnetic layer facing the non-magnetic layer,
• the first mixed layer is high in lubricant, resin, filler and void contents as compared with the magnetic layer,
• a content of magnetic components per unit volume of the first mixed layer is lower than a content of magnetic components per unit volume of the magnetic layer,
• the magnetic layer has the average thickness of 20 to 100 nm,
• wherein the average thickness t of the magnetic layer represents a distance between a first peak and a second peak of a differential curve that is derived from a luminance curve, the luminance curve being fowled by observing a cross section of the magnetic recording medium with a YAG detector to obtain a backscattered electron image of the cross section, determining values of luminance of the cross section from the backscattered electron image, and averaging the values of luminance of the cross section, and
• when an average of luminance of the non-magnetic layer is taken as 0 and a highest luminance of the magnetic layer is taken as 100 in the luminance curve, the average thickness L1 of the first mixed layer represents an average thickness of an area on a side of the magnetic layer opposite to the non-magnetic layer, where the value of luminance is in a range of 70 to 30, and the average thickness L2 of the second mixed layer represents an average thickness of an area on a side of the magnetic layer facing the non-magnetic laver, where the value of luminance is in a range of from 70 to 30.