Lattice distortion and orbital hybridization in NdFeO₃–PbTiO₃ ferroelectric thin films

Abstract

Single-phase xNdFeO3-(1 - x)PbTiO3 thin films with different dopant contents were fabricated on the Pt(111)/Ti/SiO2/Si substrate by a sol-gel route. Grain size was influenced by the dopant content effectively. A synchrotron radiation X-ray diffraction study revealed a reduced tetragonality (c/a) of the PbTiO3 lattice in the films. Distortion of the TiO6 octahedron was weakened, as investigated by Raman scattering and X-ray absorption spectra. An electronic structural study indicated that the hybridizations between O 2p and Pb 6s and Ti 3d orbitals were weakened. The decrease of lattice distortion and orbital hybridization gives rise to degradation of the ferroelectric nature in the films.

Chemical-Pressure-Modulated BaTiO3 Thin Films with Large Spontaneous Polarization and High Curie Temperature

“…In a distorted polyhedral crystal field, as shown in Figure a, the split of d x 2 – y 2 and d 3 z 2 – r 2 should be enlarged in the elongated c-BTO, while in the actual c-BTO, the split is similar to s-BTO, further proving that in c-BTO the crystal field is more in accord with the pyramid. Moreover, the obvious suppression of the splitting energy of e g and t 2g is due to the larger c / a of c-BTO . With the Ti atom deviating from the ab plane of the oxygen polyhedron, the Ti d xy –O 2p hybridization would be weakened, which is observed in the suppressed A peak in Figure b.…”

“…Moreover, the obvious suppression of the splitting energy of e g and t 2g is due to the larger c/a of c-BTO. 45 With the Ti atom deviating from the ab plane of the oxygen polyhedron, the Ti d xy −O 2p hybridization would be weakened, which is observed in the suppressed A peak in Figure 5b. The XAS results reveal the enhanced displacement of Ti in the oxygen polyhedron, which tend to form the oxygen pyramid structure.…”

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

“…These two bands then spilt into t 2g and e g sub‐bands owing to the low symmetry of the TiO 6 ligand field . Furthermore, the 3 d e g state splits into and orbitals, which points to the four side‐corner and the two apex O ions of the octahedron, respectively . The main difference between two X‐ray absorption spectra of these samples can be referred to the L 3 edge e g state which splits into two peaks in the pristine TiO 2 .…”

Structural and ferroelectric properties of perovskite Pb(1−x)(K0.5Sm0.5)xTiO3 ceramics

“…The strain originates from a very strong hybridization between Pb(6s 2 )-O(2p) and also due to a moderate Ti(3d)-O(2p) hybridization. 2,31 As a result of substitution of Pb by K/Sm, we expect a reduction of the strong Pb(6s 2 )-O(2p) bond. This reduction in the strength of the bond reduces energy of vibration which is reected in the soening of the A 1 (2TO).…”

“…Ferroelectrics are used in energy conversion devices, ultrasonic medical diagnostic apparatus, ultrasonic non-destructive detectors, pyroelectric infrared sensors and magnetoelectric sensors. [1][2][3] Pb-based ceramics are used in sensors, actuators, capacitors, nonvolatile memories, ultrasonic transducers, high piezoelectric, electromechanical and electro-optic properties etc. 4,5 PbTiO 3 has a structural phase transition from tetragonal (P4mm) to cubic (Pm3m) at 763 K. It has a highly strained lattice due to strong orbital hybridization and subsequent noncentrosymmetric lattice distortion.…”