Evolution of structural distortions in solid solutions between BiMnO3 and BiScO3

Crystal structures of solid solutions of BiMn1−xScxO3 with x=0.05, 0.1, 0.2, 0.3, 0.4, 0.5, and 0.7 were studied with synchrotron X-ray powder diffraction. The strong Jahn–Teller distortion, observed in BiMnO3 at 300 K and associated with orbital order, disappeared already in BiMn0.95Sc0.05O3. The orbital-ordered phase did not appear in BiMn0.95Sc0.05O3 down to 90 K. Almost the same octahedral distortions were observed in BiMn1−xScxO3 with 0.05⩽x⩽0.7 at room temperature and in BiMnO3 at 550 K above the orbital ordering temperature TOO=473 K. These results allowed us to conclude that the remaining octahedral distortions observed in BiMnO3 above TOO are the structural feature originated from the highly distorted monoclinic structure.