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

Orthorhombic Bi(17)Ln(7)O(36) (=Bi(0.708)Ln(0.292)O(1.5)) and triclinic BiLnO3 (=Bi(0.5)Ln(0.5)O(1.5)) with Ln = Tm, Yb and Lu, as well as a cubic 8-type Bi0.7Yb0.3O1.5, have been characterized at room temperature by Raman scattering spectrometry. The Raman spectrum deconvolution of the delta-Bi2O3 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 BiT-mO(3)->delta+Tm2O3 has also been characterized by Raman spectroscopy. (C) 2006 Elsevier Ltd. All rights reserved.