Compressive creep of dense Bi2Sr1.7CaCu2Ox

Dense polycrystalline Bi2Sr1.7CaCu2Ox (2212) was deformed from 780--835 degree C in oxygen partial pressures, PO2, of 103 to 2x104 Pa. Results could be divided into two stress regimes: one at lower stress in which the steady-state creep rate, ε, was proportional to stress, σ, having an activation energy of 990±190 kJ/mole and being independent of PO2, and another at higher stress in which ε was proportional to σn, with n∼5--6. Transmission electron microscopy supported the interpretation that in the lower-stress viscous regime, creep was controlled by diffusion, whereas dislocation glide and microcracking were responsible for strain accommodation at higher stresses