Raman modes of bismuth-layered perovskite Bi4-xLa xTi3O12 ceramic samples were studied as a function of La content from x = 0.00 to 0.75. In the low-wavenumber region (35 - 150 cm-1), the rigid mode was found to be insensitive to La substitution, while the compositional change caused a frequency upshift of one of the soft modes. In the high-wavenumber region, the results indicated that a structure transition from orthorhombic to tetragonal may occur above x = 0.75, since the B2g and B3g modes showed evidence of coalescence into Eg modes with increasing La content. Raman spectra of Bi 3.25Nd0.75Ti3O12 and Bi 3.25Sm0.75Ti3O12 are presented and compared with Bi4-xLaxTi3O12.
|Number of pages||4|
|Journal||Applied Physics A: Materials Science and Processing|
|Publication status||Published - 1 Feb 2005|
ASJC Scopus subject areas
- Materials Science(all)