Dynamic stress sensitivity of Fe73.5Cu1(Ta or W)(3)Si15.5B7 ribbons after heat treatments in vacuum

The effects of heat treatments in vacuum on magnetic permeability, Young's modulus and magnetoelastic wave amplitude were investigated in the amorphous ferromagnetic alloys Fe73.5Cu1Ta3Si15.5B7 and Fe73.5Cu1W3Si15.5B7 where tantalum or tungsten replaces niobium, which mas generally used with the same atomic fractions of the other elements. The stress sensitivity coefficient was also theoretically deduced in its development vs. the applied magnetic bias field. Structural relaxation and crystallization consequences are evidenced. Moreover an already predicted relation between the maximum of magnetoelastic wave amplitude and the minimum of stress sensitivity coefficient was confirmed.