CHARACTERISTICS OF BARIUM FERRITE TAPE FOR MAGNETIC CONTACT DUPLICATION

The magnetic properties and electromagnetic characteristics of Ba-ferrite tape for R-DAT magnetic contact duplication (MCD) were investigated. The tapes employed Ba-ferrite particles averaging 0.06 microns in diameter with an aspect ratio between 4 and 5. Ba-ferrite tapes were prepared with perpendicular, longitudinal and no orientation, and their MCD and ring-head recording (RHR) characteristics were compared. Several distinctive characteristics were observed in MCD and the desirability of perpendicular orientation at short wavelengths in MCD applications is now clear. Tilted orientation was also investigated and its output level was similar to that of perpendicular orientation in MCD, while in RHR it proved superior to perpendicular orientation in the short wavelength region. The magnetization mode of the slave tape was studied by waveform analysis using the FFT method and in conjunction with the tapes' magnetic properties, such as uniaxial anisotropy energy Ku, remanence coercivity Hr, and squareness ratio Rs. © 1990 IEEE