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.

Grapical AbstractCompositional dependence of octahedral distortion parameters Δ(M1O6) and Δ(M2O6) in solid solutions BiMn1−xScxO3 at 300 K.Figure optionsDownload as PowerPoint slide