STUDY OF MAGNETIC AFTER-EFFECTS OF COMPLEX PERMEABILITY IN AMORPHOUS COFECRSIB ALLOYS

In our work we have investigated magnetic after-effect (MAE) of comple x permeability (<(mu)over bar> = mu(1) - j mu(2)) in nearly non-magnet ostrictive ferromagnetic alloys CoFeCrSiB. MAE is represented by a rel ative change of both real (r(1)) and imaginary (r(2)) parts of the com plex reluctivity <Delta(r)over bar>/(r) over bar((r) over bar = 1/(<(m u)over bar> - 1)) which may be expressed as follows: Delta r(1)(t)/r(1 ) = r(1)(t) - r(1)(t(1))/r(1)(t(1)), Delta r(2)(t) - r(2)(t(1))/r(2)(t (1)). Time t(1) was 0.9 s for each measurement. Temperature dependence s of both real (mu(1)) and imaginary (mu(2)) parts of complex permeabi lity were measured in the temperature interval from - 175 to 100 degre es C. Computer analysis was made to evaluate the spectra of activation energies connected with MAEs. It was found that the MAE spectrum with a maximum at about 100 degrees C corresponds to the spectrum of activ ation energies with the most probable value 1.1 eV and tau(0) = 5.10(- 15) s. (C) 1997 Elsevier Science S.A.