HIGH-RESOLUTION ELECTRON-MICROSCOPY STUDY OF 60-DEGREES-DISLOCATIONS IN CU

Dissociated 60 degrees-dislocations in Cu are imaged by high-resolutio n transmission electron microscopy (HRTEM). From the separation of the partial dislocations a room-temperature stacking-fault free energy (S FE) of(40 +/- 8) mJ/m(2) is deduced. This value corresponds well to th e results obtained by the weak-beam technique, in which thicker specim en foils are used. Considered together with results on other materials , this indicates that the determination of the SFE by HRTEM is possibl e if the SFE is not extremely low and if 60''-dislocations are used fo r the analysis.