The effect of coercivity on short wavelength output for barium ferrite particulate tapes

Five barium ferrite tapes were prepared from pigments similar except for coercivity (H/sub c/). These tapes had their greatest squareness ratio in the longitudinal direction. The short wavelength output was measured on two different systems. With barium ferrite particles of 0.05- mu m diameter it is possible to make tape with a longitudinal squareness ratio of 0.68 and good surface smoothness. On an experimental test apparatus (a drum tester) the output was the same for all tapes, similar to the results reported by M. Isshiki et al. (1985). However, on an 8-mm video system the peak output increased as the pigment coercivity increased from 625 to 1100 Oe.<
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