Climb dissociation of dislocations in sapphire (α-Al₂O₃)

Structure of the Fe2O3–Al2O3(0001) interface

“…According to Frank's rule, reaction (1) is energetically favourable. However, the stacking-fault energy has been estimated to be 400 mJ m-2 (Mitchell, Pletka, Phillips and Heuer 1976) which is high compared with the intrinsic stacking-fault energies of many f.c.c. metals and semiconductors (Carter 1984).…”

Observations of partial dislocations and basal twin boundaries in shock-wave-deformed sapphire

“…For the past few decades the deformation mechanisms and the deformed microstructures of sapphire (a-A1203 single crystals) have been studied under a diverse range of conditions that include high-temperature creep (for example, Mitchell et al (1976) and Lagerlof et al (1983)), hydrostatic compression (Castaing and Cadoz 1981, Cadoz et al 1984, indentation (Hockey 1971, Hockey andLawn 1975), and shock wave deformation (Wang andMikkola 1991, Chen 1994). Deformed microstructures ranging from the dislocation-dominated to the twin-dominated have been reported from transmission electron microscopy (TEM) investigations.…”

Climb dissociation of 〈1010〉 dislocations in sapphire (α-Al2O3)

“…This fault has been previously reported to form by several processes : Mitchell et al (1976) estimate y z 4 0 0 mJ/m2 based on the height of the largest faulted dipoles observed. Phillips, Mitchell and Heuer (1981) also estimate y ,N 190 mJ/m2 based on the extent of climb dissociation of isolated edge dislocations in that system.…”