Thermal behaviour of crystal and domain structure of LSGMn-05 anode material for SOFC

• First-order structural phase transition from Pbnm to R  3¯с structure takes place in the LSGMn-05 at 340 K.
• Four domains separated by W-type twin walls (211), (101) and (110) occur in the rhombohedral LSGMn-05.
• The reversibility of the domain structure in the LSGMn-05 is probably caused by the memory of microstrains.

The structure of perovskite-type La0.95Sr0.05Ga0.95Mn0.05O3-x crystals has been investigated using high-resolution X-ray powder diffraction technique in the temperature range of 298–1173 К. A transition from orthorhombic (Pbnm) to rhombohedral (R  3¯с) phase has been detected near 340 K. A chevron-like configuration of ferroelastic domain structure was observed in rhombohedral La0.95Sr0.05Ga0.95Mn0.05O3-x crystal using the Laue technique. The chevron-like pattern is formed by the intersection of W-type domain walls (211), (101) and (110) and demonstrates the reversibility of this domain wall structure configuration at thermal cycling through the phase transition point.