Chemical characterization of perovskite BaTiO₃ doped with different concentrations of Europium via coincidence doppler broadening spectroscopy

In this study, the relationship between core electron energy band changes and chemical changes occurring at the site of positron annihilation in BaTiO₃(BTO) doped by different amounts of metallic element Eu was investigated by Coincidence Doppler broadening spectroscopy. The reduction of the background spectrum caused by a simultaneous detection system in Doppler broadening spectroscopy makes it possible to investigate the contribution of high-momentum core electrons in the process of positron annihilation in the BTO: Eu structure. The results obtained from the spectrum in the range of momenta up to 15 × 10^− 3 m₀c show that with increasing Eu, the contribution of valence electrons in the process of positron annihilation increases, but at higher momenta of the sample containing 0.05 europium compared to the samples containing 0.01 and 0.03% impurity, a higher contribution in the ratio curve in the annihilation process was observed.