Magnetic recording medium having a dimensional variation
摘要
說(shuō)明書
The ε iron oxide particles have the first shell part 22a as described above, thereby making it possible to adjust the coercive force Hc of the ε-iron oxide particles (core-shell particles) as a whole to a coercive force Hc which is suitable for recording, while maintaining the coercive force Hc of the core part 21 alone at a large value in order to ensure thermal stability. Furthermore, the ε-iron oxide particles have the second shell part 22b as described above, thereby making it possible to keep characteristics of the ε-iron oxide particles from being degraded by the generation of rust and the like on the particle surfaces, with the ε-iron oxide particles exposed to the air in the process of manufacturing the magnetic recording medium 10 and before the process. Therefore, characteristic degradation of the magnetic recording medium 10 can be suppressed.
The average particle size (average maximum particle size) D of the magnetic powder is preferably 22 nm or less, more preferably 8 nm or more and 22 nm or less, and still more preferably 12 nm or more and 22 nm or less.
