New layered perovskite family built from [CeTa2O7]− layers: coloring mechanism from unique multi-transitions

2020 ◽  
Vol 56 (61) ◽  
pp. 8591-8594
Author(s):  
Takuya Hasegawa ◽  
Atsushi Shigee ◽  
Yoshinori Nishiwaki ◽  
Makoto Nagasako ◽  
Adie Tri Hanindriyo ◽  
...  
Keyword(s):  
Layered Perovskite ◽  
Trivalent Cerium ◽  
Cerium Ion ◽  
First Time

A Ce3+-based layered perovskite compound, Dion–Jacobson type RbCeTa2O7, has been discovered for the first time by introducing only a trivalent cerium ion to form [CeTa2O7]− layers.

Tailoring the diameter of electrospun layered perovskite nanofibers for photocatalytic water splitting

2018 ◽  
Vol 6 (5) ◽  
pp. 1971-1978 ◽  
Author(s):  
André Bloesser ◽  
Pascal Voepel ◽  
Marc O. Loeh ◽  
Andreas Beyer ◽  
Kerstin Volz ◽  
...  
Keyword(s):  
Water Splitting ◽  
Fiber Diameter ◽  
Layered Perovskite ◽  
Photocatalytic Water Splitting ◽  
Nanofiber Diameter ◽  
First Time

Electrospun layered perovskite Ba5Ta4O15 nanofibers are varied in their diameter for the first time by the identification of electrospinning setup parameters controlling the resulting nanofiber diameter. The influence of fiber diameter on photocatalytic water splitting activity is revealed.

On the quenching of the luminescence of the trivalent cerium ion

1991 ◽  
Vol 189 (1) ◽  
pp. 77-80 ◽  
Author(s):  
G. Blasse ◽  
W. Schipper ◽  
J.J. Hamelink
Keyword(s):  
Trivalent Cerium ◽  
Cerium Ion

scholarly journals Direct Comparison of Structural and Electrical Properties of Epitaxial (001)-, (116)-, and (103)-Oriented SrBi2Ta2O9 Thin Films on SrTiO3 and Silicon Substrates

2000 ◽  
Vol 655 ◽  
Author(s):  
H. N. Lee ◽  
A. Pignolet ◽  
S. Senz ◽  
C. Harnagea ◽  
D. Hesse
Keyword(s):  
Thin Films ◽  
Remanent Polarization ◽  
Bottom Electrode ◽  
Three Dimensional ◽  
Laser Deposition ◽  
Layered Perovskite ◽  
Silicon Substrates ◽  
Epitaxial Thin Films ◽  
Structural And Electrical Properties ◽  
First Time

AbstractAnisotropies of the properties of the bismuth-layered perovskite SrBi2Ta2O9 (SBT) have been investigated using epitaxial thin films grown by pulsed laser deposition both on conducting Nb-doped SrTiO3 (STO) single crystal substrates and on Si(100) substrates. It has been found that the three-dimensional epitaxy relationship SBT(001)∥STO(001); SBT [110] ∥STO[100] can be applied to all SBT thin films on STO substrates of (001), (011), and (111) orientations. An about 1.7 times larger remanent polarization was obtained in (103)-oriented SBT films than in that of (116) orientation, while the (001)-oriented SBT films revealed no ferroelectricity along their c-axis. Non-c-axis-oriented SBT films with a well-defined (116) orientation were also grown on silicon substrates for the first time. They were deposited on Si(100) covered with a conducting SrRuO3 (110) bottom electrode on a YSZ(100) buffer layer.

HIGH PRESSURE BEHAVIOR OF MANGANITES BY INFRARED AND RAMAN SPECTROSCOPY

2000 ◽  
Vol 14 (29n31) ◽  
pp. 3418-3423 ◽  
Author(s):  
A. CONGEDUTI ◽  
P. POSTORINO ◽  
P. DORE ◽  
S. LUPI ◽  
S. MERCONE ◽  
...  
Keyword(s):  
High Pressure ◽  
Layered Perovskite ◽  
Maximum Pressure ◽  
Spectroscopic Techniques ◽  
Infrared And Raman Spectroscopy ◽  
Wide Pressure Range ◽  
Phonon Peak ◽  
Diamond Anvil ◽  
First Time ◽  
Absorption Measurements

The effect of hydrostatic pressure on the properties of the La 0.75 Ca 0.25 MnO 3 manganite have been studied by means of spectroscopic techniques. Raman and infrared (IR) spectra of this pseudocubic manganese perovskite have been collected for the first time over a wide pressure range (0–14 GPa) using a diamond anvil cell. Preliminary results have been obtained also in the case of the Sr 1.5 La 0.5 MnO 4 layered perovskite. The Raman measurements allow us to follow the pressure evolution of the phonon spectrum of the MnO 6 octahedron vibrational modes. Through the IR measurements we study the pressure dependence of the high-frequency octahedron stretching mode and of the broad background associated to polaronic absorption. Raman results show an abrupt discontinuity at P *~7.5 GPa in both frequency and width of some of the observed phonons. The infrared absorption measurements shows a remarkable increase of the polaronic absorption which do not completely screen the phonon peak even at the maximum pressure. Our results, which are in agreement with recent high pressure diffraction data, do not support the possibility of obtaining a metallization transition in the La 0.75 Ca 0.25 MnO 3 manganite at high pressure.

On the electronic raman scattering tensor of the trivalent cerium ion in a hexagonal crystal field

1968 ◽  
Vol 1 (13) ◽  
pp. 693-695 ◽  
Author(s):  
J.A. Koningstein ◽  
O. Sonnich Mortensen
Keyword(s):  
Raman Scattering ◽  
Crystal Field ◽  
Hexagonal Crystal ◽  
Trivalent Cerium ◽  
Electronic Raman Scattering ◽  
Cerium Ion

Visible to near-infrared persistent luminescence from Tm3+-doped two-dimensional layered perovskite Sr2SnO4

2019 ◽  
Vol 7 (27) ◽  
pp. 8303-8309 ◽  
Author(s):  
Puxian Xiong ◽  
Mingying Peng
Keyword(s):  
Near Infrared ◽  
Information Storage ◽  
Layered Perovskite ◽  
Two Dimensional ◽  
Persistent Luminescence ◽  
First Time

Here, we report a visible to near-infrared persistent luminescence from a Tm3+ doped perovskite Sr2SnO4 for the first time and demonstrate its application in information storage.

scholarly journals Optical Properties, Electronic Structures, and Photocatalytic Performances of Bandgap-Tailored SrBi2Nb2−xVxO9 Compounds

Catalysts ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 393 ◽  
Author(s):  
Sung Won Hwang ◽  
Tae Hoon Noh ◽  
In Sun Cho
Keyword(s):  
Optical Properties ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Electronic Band Structure ◽  
Solid State Reaction Method ◽  
Light Irradiation ◽  
Layered Perovskite ◽  
Electronic Band ◽  
First Time ◽  
Electronic Band Structures

Layered perovskite compounds of SrBi2Nb2−xVxO9 (x = 0.0, 0.02, 0.04, 0.06, and 0.08) were synthesized via a solid-state reaction method. Their optical properties, electronic band structures, and photocatalytic activities under visible light irradiation were investigated for the first time. The incorporation of vanadium into the SrBi2Nb2O9 lattice reduced the bandgap energies, allowing the compounds to effectively absorb visible light. Electronic band structure calculations revealed that the V 3d orbitals caused bandgap narrowing by forming an additional band below the conduction band, while the O 2p and Bi 6p orbitals dominantly contributed to the formation of the valence band. The photocatalytic activity tested under visible light irradiation (>420 nm) revealed that it increased linearly with the V content in the SrBi2Nb2−xVxO9 compounds until saturation at x = 0.06, which was attributed to improved visible light absorption originating from the reduced bandgap energies.

scholarly journals Crystallographic Features and Nature of Luminescence Centres of the Niobate and Tantalate Compounds with Layered Perovskite-Like Structure

2018 ◽  
Vol 12 (1) ◽  
pp. 2-13 ◽  
Author(s):  
Oksana Chukova ◽  
Sergiy Nedilko ◽  
Yuriy Titov ◽  
Vadym Sheludko
Keyword(s):  
Heat Treatment ◽  
Energy Levels ◽  
Luminescence Spectra ◽  
Layered Perovskite ◽  
Ultrafine Powders ◽  
Electron Transitions ◽  
First Time ◽  
Absorption Transitions

Aim and Objectives The ultrafine powders of the perovskite-like layered AII3LaM3O12 (AII = Sr, Ba; M = Nb, Ta) compounds have been synthesized by heat treatment of co-precipitated hydroxy-carbonates. The luminescence of these compounds is reported for the first time. Methods: Luminescence spectra of all studied compounds are complex and contain two main wide bands with maxima near 2.9 and 2.5 eV. These luminescence bands were assigned to radiation electron transitions in the MoO67- molecular groups of different symmetry located in the various lattice positions. Conclusion: The energy levels scheme of the MoO67- group and related radiation and absorption transitions had been proposed.

The features of cerium coordination chemistry in the complexes with tetra-15-crown-5-phthalocyanine

2006 ◽  
Vol 10 (07) ◽  
pp. 931-936 ◽  
Author(s):  
Kirill P. Birin ◽  
Yuliya G. Gorbunova ◽  
Aslan Yu. Tsivadze
Keyword(s):  
Direct Interaction ◽  
Lanthanide Ions ◽  
H Nmr ◽  
Double Decker ◽  
Composition And Structure ◽  
Cerium Ion ◽  
Sandwich Type ◽  
The Stability ◽  
First Time

For the first time, using a method of direct interaction of crownphthalocyanine and cerium(III) acetate in the presence of strong organic base, a sandwich-type double-decker cerium(IV) bis[tetra-(15-crown-5)-phthalocyaninate] [ Ce 4+( R 4 Pc 2−)2]0 ( R 4 Pc 2− = [4,5,4',5',4″,5″,4‴,5‴-tetrakis-(1,4,7,10,13-pentaoxapentadecamethylene)-phthalocyaninate-anion]) is synthesized with 60% yield. The composition and structure of the obtained complex are confirmed using spectral methods. UV-vis, IR and 1 H NMR spectroscopy and MALDI-TOF mass-spectrometry were used for characterization of the complex. It has been shown, that a particular feature of cerium ion in the complex with tetra-15-crown-5-phthalocyanine is the stability of oxidation state +4, unlike other lanthanide ions. The Ce(IV) complex has been obtained despite using a Ce(III) salt in synthesis. It has been found that the introduction of crown ether substituents in the phthalocyanine molecule results in a decreased stability of the compound to oxidation in comparison with unsubstituted and tert-butylsubstituted cerium phthalocyaninates.

scholarly journals Design of Novel Perovskite-Based Polymeric Poly(l-Lactide-Co-Glycolide) Nanofibers with Anti-Microbial Properties for Tissue Engineering

Nanomaterials ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 1127
Author(s):  
Aleksander Góra ◽  
Lingling Tian ◽  
Seeram Ramakrishna ◽  
Shayanti Mukherjee
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Biomedical Application ◽  
Cellular Protein ◽  
Dermal Fibroblasts ◽  
Layered Perovskite ◽  
Tissue Engineering Scaffolds ◽  
Gram Positive Bacteria ◽  
First Time ◽  
Microbial Effects

There is a growing need for anti-microbial materials in several biomedical application areas, such are hernia, skin grafts as well as gynecological products, owing to the complications caused by infection due to surgical biomaterials. The anti-microbial effects of silver in the form of nanoparticles, although effective, can be toxic to surrounding cells. In this study, we report, for the first time, a novel biomedical application of Ag0.3Na1.7La2Ti3O10-layered perovskite particles, blended with poly(L-lactide-co-glycolide) (PLGA), aimed at designing anti-microbial and tissue engineering scaffolds. The perovskite was incorporated in three concentrations of 1, 5, 10 and 15 w/w% and electrospun using dimethylformamide (DMF) and chloroform. The morphology of the resultant nanofibers revealed fiber diameters in the range of 408 to 610 nm by scanning electron microscopy. Mechanical properties of perovskite-based nanofibers also matched similar mechanical properties to human skin. We observed impressive anti-microbial activity, against Gram-negative, Gram-positive bacteria and even fungi, to Ag0.3Na1.7La2Ti3O10 in powder as well as nanofiber-incorporated forms. Furthermore, cytotoxicity assay and immunocytochemistry revealed that perovskite-based nanofibers promoted the proliferation of human dermal fibroblasts whist maintaining normal cellular protein expression. Our study shows that perovskite-nanofibers have potential as scaffolds for biomedical applications with anti-microbial needs.

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