High-temperature compressive creep behaviour of the perovskite-type oxide Ba0.5Sr0.5Co0.8Fe0.2O3−δ

High temperature X-ray diffraction and thermo-gravimetrical analysis of the cubic perovskite Ba0.5Sr0.5Co0.8Fe0.2O3−δ under different atmospheres

“…The transition from the cubic to the hexagonal polymorph is quite complex, involving formation of several phases [13][14][15][16][17][18][19] . The structural phase transformation has also been observed by compressive creep measurements 20,21 , showing that cation diffusion is slowed down by formation of the hexagonal polymorph, reflecting the slow kinetics of the phase reaction below 900 ºC. The creep rate of BSCF ceramics is exceptionally high, illustrating the challenge of keeping the cation diffusion low while optimizing the oxygen vacancy mobility 20 .…”

“…The structural phase transformation has also been observed by compressive creep measurements 20,21 , showing that cation diffusion is slowed down by formation of the hexagonal polymorph, reflecting the slow kinetics of the phase reaction below 900 ºC. The creep rate of BSCF ceramics is exceptionally high, illustrating the challenge of keeping the cation diffusion low while optimizing the oxygen vacancy mobility 20 . The low creep resistance questioning the actual use of BSCF in high temperature gas separation membranes and several attempts to stabilize BSCF by chemical substitution have appeared, both to avoid the formation of the hexagonal polymorph and to increase the creep resistance [22][23] .…”

Creep behaviour of tubular Ba0.5Sr0.5Co0.8Fe0.2O3−δ gas separation membranes

“…11 Nevertheless, compared to the number of reports on functional aspects, there is still a deficiency in the field of mechanical testing of BSCF membranes. 12,13 Hence, the characterization of the creep behaviour of BSCF based dense ceramic MIEC membranes was defined as an important task in the research alliance "MEM-BRAIN" of the Helmholtz Association of German Research Centres. 1 In this context, the aim of the current work is to present compressive creep results of tubular BSCF membranes under different atmospheres (air, 20 mbar, 5 × 10 −5 mbar total pressure) in a wide range of temperatures (600-950 • C).…”

“…12, in the present study creep tests were performed at constant load and with stepwise increasing temperature. This methodical approach allows investigating more temperature steps.…”

Microstructure and mechanical properties of Ba0.5Sr0.5Co0.8Fe0.2O3−δ perovskite-structured oxides doped with different contents of Ni

“…However, how to improve the properties of BSCF including thermal stability, mechanical property and permeability at operating conditions remains to be dealt with. For instance, a phase transition from cubic to hexagonal structure occurs at elevated temperature and reduces the permeation rate of BSCF [3]; additionally, spin transition of Co 3+ decreases the Young's modulus of the membrane at elevated temperature, thereby mechanically destabilising the material [4].…”