Long-range ordering and disordering in nearly stoichiometric CuAu (49.
4 at% Cu, 50.5 at% Au) has been investigated by dynamic in situ resist
ometry. Linear cooling and linear heating, starting from constant init
ial conditions, was performed at different rates of temperature change
. For cooling runs the usual effect of undercooling was found, increas
ing with increasing cooling rate. For heating runs, however, a shift o
f the transformation temperature to lower temperatures with increasing
heating rate was observed. This is similar to what has been previousl
y reported for cyclic measurements (retro-effect). This effect is not
influenced by isothermal annealing at 300 degrees C; it is probably co
nnected with the nucleation stage of the phase transformation and ther
eby with the microstructure of the material. (C) 1997 Elsevier Science
Limited.