Ti 2p and O 1s X-ray absorption of TiO2 polymorphs

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

“…18 The separation between the L 3 and L 2 edges is attributed to Ti 2p 3/2 ͑L 3 ͒ and 2p 1/2 ͑L 2 ͒ spin orbit splitting, which is around 5.3 eV and is comparable to that observed in TiO 2 and other mixed perovskite compounds. [8][9][10][11][12][13][14] The crystal field at both the L 3 and L 2 edges splits the 3d band into t 2g and e g subbands. 21 The split observed at the D peak, shown in greater detail in Fig.…”

“…These results indicate that, although the distortion on the titanium site decreased when Pb atoms were replaced by La atoms, a perfect octahedral symmetry such as that of SrTiO 3 The origin of this splitting in the e g states is a controversial subject in the literature. [8][9][10][11][12][13][14][18][19][20] In their first paper, De Groot et al 18 proposed that the different distortions from O h symmetry observed in the Ti 2p XANES spectra of TiO 2 compounds produced dissimilar splitting of the e g orbitals. However, according to Crocombette and Jollet, 20 who calculated the Ti 2p x-ray absorption edge of these compounds by a configuration interaction code, the existence of this splitting cannot be attributed to differences between the titanium oxides in the first coordination shell of the cation.…”

“…7 Although the use of x-ray absorption spectroscopy to study ABO 3 and mixed perovskite compounds has been limited mainly to the analysis of K-edge spectra, the electronic structure of the transition metals in these compounds has recently been studied by soft x-ray absorption spectroscopy measurements of Ti L 3,2 and O K edges. [8][9][10][11][12][13][14] When applied to mixed perovskite compounds, these studies proved very useful in shedding light on how compositional substitution influences the electronic structure of these systems. [11][12][13]15 Theoretical calculations have shown that hybridized states of Ti 3d and O 2p and covalent bonding of Pb-O crucially affect ferroelectric stability in the PbTiO 3 compound.…”

Investigation of the amorphous to crystalline phase transition of chemical solution deposited Pb(Zr0.3Ti0.7)O3 thin films by soft X-ray absorption and soft X-ray emission spectroscopy

“…4a Ti upper spectrum, 700 °C) prominent peaks which are related to the crystal field splitting of Ti 4+ in an octahedral symmetry. The first two peaks (at 458 EV and 460 eV) belong to the 2p 3/2 (t 2g and e g ) and the third and fourth peak (464.35 eV and 466.7 eV) belong to the 2p 1/2 (t 2g and e g )transitions [49][50][51][52][53]. In addition, the TEY`s and TFY`s are rather similar for all annealing temperatures which indicates equivalent bulk and surface properties.…”

“…This particular feature corresponds to a Ti 4+ ion in the rutile type structure (D 2h ) with a slight distortion from the O h symmetry. Ti in the anatase phase shows an opposite intensity distribution (peak A larger than peak B) [52,53,54]. Because anatase is typically the low temperature phase one would first expect an anatase structure for the #350 °C sample.…”