Structural and Lattice-Dynamical Properties of Tb₂O₃ under Compression: A Comparative Study with Rare Earth and Related Sesquioxides.

ABSTRACT: We report a joint experimental and theoretical investigation of the high pressure structural and vibrational properties of terbium sesquioxide (Tb₂O₃). Powder X-ray diffraction and Raman scattering measurements show that cubic Ia3̅ (C-type) Tb₂O₃ undergoes two phase transitions up to 25 GPa. We observe a first irreversible reconstructive transition to the monoclinic C2/m (B-type) phase at ∼7 GPa and a subsequent reversible displacive transition from the monoclinic to the trigonal P3̅m1 (A-type) phase at ∼1₂ GPa. Thus, Tb₂O₃ is found to follow the well-known C → B → A phase transition sequence found in other cubic rare earth sesquioxides with cations of larger atomic mass than Tb.

SUBMITTER: Ibanez J 

PROVIDER: S-EPMC7588034 | biostudies-literature | 2020 Jul

REPOSITORIES: biostudies-literature