A perpendicularly oriented coating of rice shaped iron particles

A new particulate recording medium containing iron fine particles of rice shape has been prepared, and its magnetic and surface properties are investigated. A special magnetic orientation technique was employed to orientate the particles of high saturation magnetization in order to reduce redisorientation of the particles due to demagnetization field and to minimize surface roughening effects occuring during the orientation process. Relatively high squareness ratio (SQR⊥) of the medium in the vertical direction was obtained such asSQR⊥= 0.65after a correction for the demagnetization field, thus providing better recording characteristics especially in the short wave range.