Structural analysis, optical and dielectric function of [Ba_0.9Ca_0.1](Ti_0.9Zr_0.1)O₃ nanocrystals

This work presents the identification of inter-band transitions in the imaginary part of the dielectric function (ϵ₂) derived from the Kramers-Kronig analysis for [Ba_0.9Ca_0.1](Ti_0.9Zr_0.1)O₃ (BCZT) nanocrystals synthesized by the modified Pechini method. The analysis started with the chemical identification of the atoms that conform BCZT in the valence loss energy region of a high energy-resolution of electron energy loss spectroscopy. The indirect band energy (E_g) was determined in the dielectric response function. This result is in agreement with the UV-Vis technique, and it obtained an optical band gap of 3.16 eV. The surface and volume plasmon peaks were observed at 13.1 eV and 26.2 eV, respectively. The X-ray diffraction pattern and the Rietveld refinement data of powders heat treated at 700 °C for 1 h suggest a tetragonal structure with a space group (P4 mm) with the average crystal size of 35 nm. The average particle size was determined by transmission electron microscopy.