抄録
The kinetic behavior of the Heusler(L21)-type ordering in the stoichiometric AuAgZn2 alloy quenched from the CsCl(B2)-type ordered region was studied by X-ray diffraction. The degrees of the B2-type order (S1) and the L21-type order (SH) and the domain size of the L21-type superstructure were measured as a function of annealing time during the isothermal ordering process at 366, 386 and 406 K. The isothermal change of SH was analyzed by the standard rate equation and the activation energy of the L21-type ordering was found to be 46 kJ/mol. The increase of the L21-type domain size was proportional to the three-tenth power of the annealing time. The temperature dependence of S1 and SH were also studied. S1 showed a minimum whereas SH decreased to zero at the critical temperature of the L21-type order on heating.
