Investigation on phase and Raman spectra of Ba3(CaTa2-yTiy)O9-δ (y = 0 – 0.50) system

Abstract

The perovskite-based oxides have widespread applications in sensors, dielectric resonators, gas separation membranes, and proton-conducting fuel cells. An attempt has been made here to characterize phase(s) and Raman spectra of Ba3(CaTa2-yTiy)O9-δ (y = 0 – 0.50) system. The X-ray diffraction patterns confirm the formation of trigonal phase (space group P$$\bar 3$$m1 or D33d, Z = 3) along with cubic structure (space group Pm$$\bar 3$$m or Oh1, Z = 1). Titanium substitution introduces disordering in the structure. Raman modes corresponding to A1g and Eg were clearly assigned. Bands at ~350, ~400, and ~800 cm−1 are associated with vibration of octahedron A1g(O), vibration of 2Eg(O), and stretching mode A1g(O), respectively. The creation of oxygen vacancies with titanium makes the compounds useful for industrial application.

Keywords

• x-ray diffraction
• raman spectroscopy
• perovskite-type oxides
• oxygen vacancies