Electronic structure of Pb1−xLaxTiO3 ferroelectric materials from Ti 2p and O 1s soft x-ray absorption spectroscopy

Abstract

The electronic structure of Pb 1−x La x TiO 3 ͑PLT͒ compounds for x ranging from 0 to 30 at. % of La is investigated by means of soft x-ray absorption near edge structure ͑XANES͒ at the Ti L 3,2 and O K edges. The greatest modification in the structure of the Ti 2p XANES spectra of the PLT compounds is observed in the region of the high energy peak of the L 3 edge ͑e g states͒, which exhibits a splitting in the undoped sample. As the amount of lanthanum increases, this splitting becomes less pronounced. This modification is interpreted as a decrease in the degree of disorder of titanium atoms, which is correlated to the substitution of Pb by La atoms. The structural changes observed at the low energy peaks of the O K-edge XANES spectra of the PLT compounds may be interpreted in terms of hybridization between O 2p, Ti 3d, and Pb 6p orbitals. A decrease in the degree of hybridization observed as Pb atoms are replaced by La atoms may be related to the differences in the ferroelectric properties observed between x = 0.0 and x = 0.30 compounds.

Local structure and hybridization states in Ba0.9Ca0.1Ti1−Zr O3 ceramic compounds: Correlation with a normal or relaxor ferroelectric character

“…In lead-based ferroelectric ceramic systems, the ferroelectric character is directly correlated with the electronic properties of both A-site (Pb 2+ ) and B-site (Ti 4+ ) ions [17,18]. Many studies have shown that the density of states (DOS) of oxygen and titanium atoms could provide a more direct correlation with the ferroelectric stability of perovskite-based compounds [19][20][21][22][23][24][25][26][27][28]. They have also reported a significant modification in the hybridization among O 2p, Pb 6sp and Ti 3d states when the ferroelectric character changes.…”

“…In the PLZT and Pb 1Àx Ba x Zr 1Ày Ti y O 3 complex ferroelectric compounds, a reduction in the degree of hybridization between O 2p and Pb 6sp (Ti 3d) states as the amount of La (Ba) increased was directly related to the manifestation of the relaxor character [23][24][25][26][27][28].…”

Co‐doping Nitrogen/Sulfur through a Solid‐State Reaction to Enhance the Electrochemical Performance of Anatase TiO2 Nanoparticles as a Sodium‐Ion Battery Anode

“…Figure a presents the normalized absorption spectra at Ti L 3,2 edges of the N/S‐TiO 2 and pristine TiO 2 . For TiO 2 , the two small peaks at 456–458 eV are related to a transition which is normally forbidden in LS coupling, but becomes allowed due to the multipole pd interactions ,. The separated L 3 and L 2 edges could be assigned to Ti 2 p 3/2 and 2 p 1/2 spin orbit coupling in the Ti 2 p core states, separately .…”

Room temperature photoluminescence of BCT prepared by Complex Polymerization Method

“…The order parameter is related to the presence of TiO 6 clusters, whereas the disorder is related to the presence of TiO 5 clusters. It is believed that PL occurs due to interaction of TiO 5 -TiO 6 clusters [20,21]. de Figueiredo et al [22] observed the PL phenomenon in Ca 0.95 Sm 0.05 TiO 3 (CT:Sm) only in disordered structure.…”