Bartsch, M., Messerschmidt, U., Vasilev, A. D.
Extended dislocations and dislocation dipoles in plastically deformed SiC single crystals
Physica Status Solidi A 146, pp 173-184 (1994)
SiC single crystal plates are deformed in bending at 1700 and 1750 degrees C in air. Smoothly curved extended dislocations of total (a/3) (112) Burgers vectors are formed, many of which are arranged in groups of parallel dislocations on basal planes. The slip planes of different groups have mostly distances smaller than 100 nm. The stacking fault energy of about 1.7 mJ/m/sup 2/ is estimated from the width of the dissociated dislocations. Frequently, dipoles of extended dislocations having much lower width form, which agrees with calculations of their equilibrium configurations. The shape of dislocations crossing each other on parallel planes depends on the sequence of the partial dislocations and can be understood by the mutual elastic interactions of the latter. It is argued that long-range elastic dislocation interactions essentially contribute to the flow stress at these high temperatures.