Zener relaxation in ordered and disordered Fe–(22–28%)Al alloys

The Zener relaxation in three Fe–Al alloys with 22, 26 and 28 at.% Al has been studied by isothermal measurements of elastic-energy-dissipation as a function of vibrating frequency in the range from 10−4 to 102 Hz. The activation energy of the Zener relaxation has been determined as follows (in kJ/mol): 238 in Fe–22Al of the disordered bcc (A2) structure, 270 in Fe–22Al of the D03 + A2, two phase structure, 235 in Fe–26Al of the B2 ordered structure, 286 in Fe–26Al of the D03 ordered structure, and 276 in Fe–28Al–3Cr at temperature close to the D03 ↔ B2 transition.