Defects or charge transfer: Different possibilities to explain the photoluminescence in crystalline Ba(Zr x Ti 1−x )O 3

Souza, Agda Eunice de; Sasaki, Guilherme S.; Camacho, Sabrina A.; Teixeira, Silvio Rainho; Li, Máximo S.; Longo, Elson

doi:10.1016/j.jlumin.2016.06.033

Cited by 9 publications

(3 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For example, in BaTiO3, the off-centering displacement of Ti in the [TiO6] octahedron is the origin of its exceptional dielectric properties [2]. Very recently, different possibilities to explain the PL emissions in crystalline Ba(ZrxTi1-x)O3 were associated to the isomorphic Zr/Ti substitutions and structural distortions at the [ZrO6] octahedra [3].…”

Section: Introductionmentioning

confidence: 99%

Mechanism of photoluminescence in intrinsically disordered CaZrO3 crystals: First principles modeling of the excited electronic states

Oliveira

Gracia

Assis

et al. 2017

Journal of Alloys and Compounds

Self Cite

View full text Add to dashboard Cite

CaZrO3 (CZO) powders were synthesized at different temperatures (400, 600, 800, and 1000 °C) and characterized by X-ray diffraction, Raman and ultraviolet-visible spectroscopic methods, along with photoluminescence (PL) emissions. First principle calculations based on the density functional theory (DFT), using a periodic cell models, provide a theoretical framework for understanding the PL spectra based on the localization and characterization of the ground and electronic excited states.Fundamental (singlet, s) and excited (singlet, s*, and triplet, t*) electronic states were localized and characterized using the ideal and distorted structures of CZO. Their corresponding geometries, electronic structures, and vibrational frequencies were obtained. A relationship between the different morphologies and structural behavior has also been established. Polarized structures were identified by the redistribution of the 4dz2, 4dyz, and 4dxy (Zr) orbitals at the conduction band and the 2pz (O) orbital in the valence band for s, s* and t*. Analysis of the vibrational eigenvector modes of these electronic states reveals a relationship between them via asymmetric bending and stretching modes that arise from Zr atom displacements due to polyhedral [ZrO6] distortion. Furthermore, the results provided an insight into the PL emissions of the as-synthesized CaZrO3 and led to the conclusion that the presence of electronically excited states is strongly related to the structural order-disorder effects (polyhedral distortion) at short range for both [ZrO6] and [CaO8] clusters.

show abstract

Section: Introductionmentioning

confidence: 99%

Mechanism of photoluminescence in intrinsically disordered CaZrO3 crystals: First principles modeling of the excited electronic states

Oliveira

Gracia

Assis

et al. 2017

Journal of Alloys and Compounds

Self Cite

View full text Add to dashboard Cite

show abstract

“…The Zr 4+ doped with BT material can improve ferroelectric and piezoelectric properties [2]. Chemically, Zr 4+ has a higher level of stability than Ti 4+ because Zr 4+ inhibits conduction by electrons moving between Ti 4+ ions [3]. BaTiO3 material can reduce the curie's temperature by doping the Zr 4+ .…”

Section: Introductionmentioning

confidence: 99%

Structural and Optical Properties of Ba(Zr0.3Ti0.7)O3 and Ba(Zr0.5Ti0.5)O3 Thin Films Prepared by Sol-Gel Method

Dewi¹,

Luqman²,

Krisman³

et al. 2023

J. Nano- Electron. Phys.

View full text Add to dashboard Cite

BaZrxT1 -xO3 (BZT) thin film with x  0.30 and 0.50 has been prepared with FTO glass substrate using a sol-gel method with an annealing temperature of 600 °C for one hour. BZT thin films are characterized using XRD and UV-vis to analyze their structural and optical properties. XRD spectra analysis of BZT thin films for the composition x  0.3 and 0.5 crystal structure obtained is perovskite tetragonal. It has good crystals, while the diffraction angle 2 would increase as the Zr content increase. The optical properties of BZT thin films were also analyzed, where the absorbance value increased with increasing Zr content at a wavelength of 300 -375 nm. The band gap energy increases when composition (x) increases, and the highest band gap energy for composition x  0.5 is about 3.54 eV.

show abstract

“…This effect is intrinsically related to ferromagnetic, photoluminescent, and gas-sensing properties. Additionally, the electrical conduction of CeO 2 films is virtually dominated by cluster-to-cluster charge transfer (CCCT) processes, indicating an electron quantum tunneling/hopping mechanism on the film response, which stems from interaction between intrinsic vacancies among the clusters, such as [CeO 8 ] O ′...[CeO 7 ·V O •• ]...[CeO 8 ] O ′, which can still be present even above room temperature …”

Section: Introductionmentioning

confidence: 99%

Novel Approaches of Nanoceria with Magnetic, Photoluminescent, and Gas-Sensing Properties

et al. 2020

Self Cite

View full text Add to dashboard Cite

The modification of CeO2 with rare-earth elements opens up a wide range of applications as biomedical devices using infrared emission as well as magnetic and gas-sensing devices, once the structural, morphological, photoluminescent, magnetic, electric, and gas-sensing properties of these systems are strongly correlated to quantum electronic transitions between rare-earth f-states among defective species. Quantitative phase analysis revealed that the nanopowders are free from secondary phases and crystallize in the fluorite-type cubic structure. Magnetic coercive field measurements on the powders indicate that the substitution of cerium with lanthanum (8 wt %), in a fluorite-type cubic structure, created oxygen vacancies and led to a decrease in the fraction of Ce species in the 3+ state, resulting in a stronger room-temperature ferromagnetic response along with high coercivity (160 Oe). In addition to the magnetic and photoluminescent behavior, a fast response time (5.5 s) was observed after CO exposure, indicating that the defective structure of ceria-based materials corresponds to the key of success in terms of applications using photoluminescent, magnetic, or electrical behaviors.

show abstract

Defects or charge transfer: Different possibilities to explain the photoluminescence in crystalline Ba(Zr x Ti 1−x )O 3

Cited by 9 publications

References 27 publications

Mechanism of photoluminescence in intrinsically disordered CaZrO3 crystals: First principles modeling of the excited electronic states

Mechanism of photoluminescence in intrinsically disordered CaZrO3 crystals: First principles modeling of the excited electronic states

Structural and Optical Properties of Ba(Zr0.3Ti0.7)O3 and Ba(Zr0.5Ti0.5)O3 Thin Films Prepared by Sol-Gel Method

Novel Approaches of Nanoceria with Magnetic, Photoluminescent, and Gas-Sensing Properties

Contact Info

Product

Resources

About