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, You ng's modulus and magnetoelastic wave amplitude were investigated in th e amorphous ferromagnetic alloys Fe73.5Cu1Ta3Si15.5B7 and Fe73.5Cu1W3S i15.5B7 where tantalum or tungsten replaces niobium, which mas general ly used with the same atomic fractions of the other elements. The stre ss sensitivity coefficient was also theoretically deduced in its devel opment vs. the applied magnetic bias field. Structural relaxation and crystallization consequences are evidenced. Moreover an already predic ted relation between the maximum of magnetoelastic wave amplitude and the minimum of stress sensitivity coefficient was confirmed.