Raman scattering characterization of bismuth based mixed oxides with Bi2O3 related structures

Abstract Orthorhombic Bi 17 Ln 7 O 36 (=Bi 0.708 Ln 0.292 O 1.5 ) and triclinic BiLnO 3 (=Bi 0.5 Ln 0.5 O 1.5 ) with Ln = Tm, Yb and Lu, as well as a cubic δ-type Bi 0.7 Yb 0.3 O 1.5 , have been characterized at room temperature by Raman scattering spectrometry. The Raman spectrum deconvolution of the δ-Bi 2 O 3 type cubic form allowed us to establish a correlation between the different phases of these mixed metallic oxides for the lattice modes as well as for the internal species. Using the empirical relation from Hardcastle, the Bi O bond lengths have been estimated from the stretching frequency value observed at 635, 597 or 639 cm −1 for cubic, orthorhombic or triclinic forms, respectively. A comparison with the X-ray results is discussed. The peritectoidic transformation BiTmO 3 → δ + Tm 2 O 3 has also been characterized by Raman spectroscopy.