Raman and x-ray photoelectron spectroscopy study of ferroelectric switching in Pb(Nb,Zr,Ti)O3 thin films

Abstract

The ferroelectric switching process in Pb(Nb,Zr,Ti)O 3 thin films was studied by performing Raman spectroscopy and x-ray photoelectron spectroscopy (XPS). Switching was achieved using a macroscopic polarization experiment above and below the Curie temperature. Two samples in opposite switching states were obtained and characterized in order to correlate both vibrational-bands distortions of the bulk and changes in the elemental states of the surface. We have assigned the symmetrical A 1 (2TO) (332 cm À1) and A 1 (3TO) (603 cm À1) vibrational modes to the ferroelectric phase. Their corresponding peaks-area showed symmetrical behavior when the sample was polarized in opposite directions, while the quantity of phonons associated to the ferroelectric phase was conserved. We found that binding energies in the XPS signals of the Ti 2p, Nb 3d, Zr 3d, and Pb 4f levels increased when comparing to the values found in a non-polarized sample. Moreover, a high population of oxygen vacancies diffused to the surface of the ferroelectric capacitor under the application of external electric fields. Our novel results show the correlation between vibrational and ferroelectric behaviors and highlight the possibility to perform in situ treatments to decrease the degradation of current technological capacitors. V

Local strain heterogeneity and elastic relaxation dynamics associated with relaxor behavior in the single-crystal perovskite Pb(In1/2NbHe1, Carpenter2, Lampronti3 et al. 2017Phys. Rev. B6030View full textAdd to dashboardCite

“…The peak of binding energy (BE) at 529.3 eV corresponds to oxygen in the PIN-PZ-PMN-PT lattice, including Pb-O, In-O, Zr-O, Ti-O, Mg-O, and Nb-O bonds. The BE of the component with lower intensity was close to 531.0 eV, and has been attributed to the presence of oxygen vacancies in crystals or chemically adsorbed oxygen on the crystal surface [27,28]. The ratio of areas under the peaks I and II is often used to estimate oxygen vacancy, and the area ratio A I /A II obtained here was 0.44, indicating a low oxygen vacancy concentration.…”

Colossal permittivity behavior and its origin in rutile (Mg1/3Ta2/3)xTi1-xO2

“…1c has four components: a main peak at ~530.2 eV and a lower-energy tail at ~528.6 eV, corresponding to the bulk Ti-O and Mg/Ta-O cation-oxygen bond. Two further higher-energy peaks at 532.5 eV and at 531.5 eV are assigned to the presence of oxygen vacancies and surface hydroxyl, respectively 33 . These results suggests the Ta 5+ to be responsible for the reduction of Ti 4+ to Ti 3+ , which is consistent with previously reported results 9 and also quite similar to that of the M + Nb co-doped rutile TiO 2 (M = In, Ga, Zn), where Nb 5+ substitutions locally induce the reduction of Ti 4+ into Ti 3+   1, 13, 14 .…”

Quasi-intrinsic colossal permittivity in Nb and In co-doped rutile TiO2nanoceramics synthesized through a oxalate chemical-solution route combined with spark plasma sintering

“…5(b)) shows a main peak at 529.8 eV with a low energy tail at B528.2 eV, which corresponds to cation-oxygen bonds such as bulk Ti-O and In-Nb-O. 33 It should be noted here that Nb 5+ dopants cannot introduce oxygen vacancies in TiO 2 ; 34,35 however, when the acceptor dopants are introduced in TiO 2 , oxygen vacancies can be formed for charge compensation as follows, 33 It should be noted here that Nb 5+ dopants cannot introduce oxygen vacancies in TiO 2 ; 34,35 however, when the acceptor dopants are introduced in TiO 2 , oxygen vacancies can be formed for charge compensation as follows,…”