Measurement of Young's Modulus and Stress Analysis of a Magnetic Thin Film

Abstract

In order to evaluate the mechanical properties of a very thin film, this paper proposes a convenient method for separately determining Young's moduli of two thin films of a magnetic recording medium. Furthermore, the particular stress distribution inside a magnetic recording film (two bonded thin films) is analyzed. The internal stress in the medium is not uniform when the medium is subjected to unidirectional tension. The analysis shows that the difference in Poisson's ratio on two thin films causes flexure of the two bonded films under tension, as well as shearing stress at the interface between the magnetic layer and the substrate. Since the shearing stress may cause fatigue damage of the tape edge, detailed FEM analysis on its distribution is carried out.