Temperature-dependent Raman spectroscopy, domain morphology and photoluminescence studies in lead-free BCZT ceramic

Abstract Present work focuses on detailed temperature-dependent x-ray diffraction, Raman scattering, domain configuration and photoluminescence (PL) studies in the (Ba0·85Ca0.15) (Zr0·10Ti0.90)O3 (BCZT) ceramics. The comprehensive Raman spectroscopy analysis in the present work not only validates the presence of the intermediate orthorhombic phase in BCZT, but also provides evidence of another transition: rhombohedral R3c phase to R3m at low temperature. Temperature behaviour of the lowest frequency transverse optical mode (soft E (TO) phonon) and hard modes were studied. Temperature dependence of peak positions, intensities, and linewidths of Raman phonon modes signalled the presence of phase transitions near −50 ± 5 °C, 0±5 °C, 35±5 °C and 110 ± 10 °C. Evolution of domain morphology occurring with phase transitions above room temperature was studied by piezoresponse force microscopy technique. Analysis of PL spectra revealed disorder/heterogeneity in the sample and indicated the existence of self-trapped excitons. PL spectra is composed of four distinct colour components (∼2.55eV:blue, ∼2.32eV:green, ∼2.08eV:orange and ∼1.78eV:red).