Magnetic recording medium having a dimensional variation
摘要
說(shuō)明書
In the first embodiment described above, a case where the ε-iron oxide particles have the core-shell structure has been described, but the ε-iron oxide particles may include an additive instead of the core-shell structure, or have the core-shell structure and also include an additive. In this case, Fe of the ε-iron oxide particle is partially substituted with the additive. The ε-iron oxide particles include an additive, thereby also allowing the coercive force Hc of the ε-iron oxide particles as a whole to be adjusted to the coercive force Hc suitable for recording, and thus the ease of recording to be improved. The additive is a metal element other than iron, preferably a trivalent metal element, more preferably one or more metal elements selected from the group consisting of aluminum (Al), gallium (Ga), and indium (In).
Specifically, the ε-iron oxide including the additive is an ε—Fe2-xMxO3 crystal (where M represents a metal element other than iron, preferably a trivalent metal element, more preferably one or more metal elements selected from the group consisting of Al, Ga, and In. x represents, for example, 0<x<1).
The magnetic powder may be a barium ferrite magnetic powder. The barium ferrite magnetic powder includes magnetic particles of an iron oxide containing, as its main phase, barium ferrite (hereinafter referred to as “barium ferrite particles”).
The average particle size of the barium ferrite magnetic powder is 50 nm or less, more preferably 10 nm or more and 40 nm or less, still more preferably 15 nm or more and 30 nm or less.
