Characterization of surface changes to metal evaporated and metal particle media following durability tests in helical scan Hi-8 recorders at ambient and high humidity conditions

Abstract

X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) have been employed in the surface characterization of two commercial tapes following durability tests in helical scan Hi-8 video recorders. Mechanical, physical and chemical changes to the surfaces of the metal evaporated thin film (ME) and metal particle (MP) tapes were compared to dropout errors and signal degradation under ambient and high humidity conditions. The signal measurements were correlated to changes in the physical and chemical structure of the surface with specific changes correlating well with dropout growth. Extensive surface analyses were used to identify the failure mechanisms in the ME and MP tapes and these were found to result from cyclic stressing and fatigue on the immediate substrate of the media. The durability of the tapes was assessed through stop motion (still-frame) and cycling tests, where error growth and signal degradation were measured as a function of running time. The signal performance of the ME tape was found to be quite different from that for the MP tape with dropout errors and signal degradation increasing at a much earlier stage.