AN IN-SITU TEM STUDY OF THE L1(2) TO DO19 PHASE-TRANSFORMATION IN THEINTERMETALLIC COMPOUND FE3GE

The nucleation stage of the L1(2)-->DO19 transformation in Fe3Ge has b een studied by in-situ heating experiments in the TEM. Stacking faults , which were identified as embryos of the product DO19 phase, were obs erved to generate from sources such as twin boundaries and superdisloc ations by the formation of stair-rod dislocations. Two types of stair- rod dislocations were identified and these had overall Burgers vector content of a perfect screw dislocation and zero, respectively. Thicken ing was via a stacking fault overlapping process. (C) 1997 Elsevier Sc ience Limited.