Creep recovery of CoO single crystals

Abstract

The recovery of creep resistant substructure in CoO single crystals was studied at temperatures of 1000, 1050, and 1100 ~ C in air. Compressive creep specimens were crept under a stress of 13.8 MN m -2. to a strain early in the secondary stage of creep, then allowed to recover for varying periods of time under a reduced stress of 0.69 MN m -2 . Recovery was detected by increased amounts of creep strain which occurred upon reapplication of the 13.8 MN m -2 stress. An apparent activation energy of 71.7 -+ 10 kcal mol -a was obtained for the recovery process. Experimental evidence suggests that the primary recovery mechanism involves the climb of dislocations within subgrain boundaries.

Plastic deformation of CoO single crystals

“…T > 0.6 TM) [3][4][5][6][7][8][9]. These two oxides appear to be similar with metal deficient nonstoichiometry, NaCI type crystal structure (lattice parameter 0.418 nm for NiO and 0.426 nm for CoO) and antiferromagnetic ordering at low temperature (TN = 525 K for NiO and 290 K for CoO).…”