Oxygen-octahedral A1g (O) phonons for both 1:2 ordered x BaTiO3 + (1-x) Ba (Mg13 Ta23) O3 (0≤x≤:0.05) and 1:1 ordered xCa (Sc12 Nb12) O3 + (1-x) Ba (Sc12 Nb12) O3 (0≤x≤:0.25) ceramics were investigated using Raman scattering. Lineshapes of A1g (O) phonons directly reflect structural characteristic of TiO6, TaO6, ScO6, and NbO6 octahedral cages that are strongly correlated with microwave performance of the samples. The larger width of stretching A1g (O) phonon, implies poor crystalline structure and short phonon lifetime, giving us lower value of Q×f. The atomic polarizabilities of Ta5+, Ti4+, Ca2+, Sc3+, and Nb5+ have a strong influence on the structure of oxygen octahedron that dominates microwave performance of x BaTiO3 + (1-x) Ba (Mg13 Ta23) O3 and xCa (Sc12 Nb12) O3 + (1-x) Ba (Sc12 Nb12) O3 ceramics.
ASJC Scopus subject areas
- Physics and Astronomy(all)