| abstract |
Acicular hematite particles suitable as non-magneticnparticles for a non-magnetic undercoat layer of anmagnetic recording medium have a geometrical standardndeviation of the major axis diameter of not more thann1.50, a geometrical standard deviation of the minor axisndiameter of not more than 1.35, a BET specific surfacenarea of 35.9 to 150 m 2 /g and an average major axisndiameter of 0.004 to 0.295 µm. |