Journal Article
The Finer Structure of Magnetic Tape: Microscope Studies
Journal of the Audio Engineering Society · Volume 6 · Issue 4 · pp. 225–233 · October 1958
Abstract
Properties of tape coatings and bases are briefly reviewed. Utilizing tissue microtome techniques, sections of 1/4" magnetic tape in three planes were prepared at 2 to 4 microns (80 to 160 micro-inches) thickness. Microscopy, under polarized and other lighting, and using up to 1500 magnification, revealed the internal structure and defects in the oxide coating. The shearing stress of the microtome technique tested coating adhesion, oxide shedding and coating integrity. Principal internal defects were pinholes, foreign bodies and oxcide particle aggregates. Section profiles of coatings are related to surface features previously described. The behavior of polyester and acetate bases, in sectioning, was demonstrated. The lack of visible orientation of oxide particles at 1500 magnification, is presented. The possible relation of fine structure to recording performance is discussed.
