Decreasing Structural Dimensionality of Double Perovskites for Phase Stabilization toward Efficient X-ray Detection

2021 ◽  
Author(s):  
Da Chen ◽  
Guangda Niu ◽  
Shiqiang Hao ◽  
Liubing Fan ◽  
Jing Zhao ◽  
...  
Keyword(s):  
Double Perovskites ◽  
X Ray ◽  
Phase Stabilization ◽  
Structural Dimensionality

The role of π-bonding on the high temperature structure of the double perovskites Ba2CaUO6and BaSrCaUO6

2015 ◽  
Vol 44 (36) ◽  
pp. 16036-16044 ◽  
Author(s):  
Emily Reynolds ◽  
Gordon J. Thorogood ◽  
Maxim Avdeev ◽  
Helen E. A. Brand ◽  
Qinfen Gu ◽  
...  
Keyword(s):  
Phase Transition ◽  
High Temperature ◽  
Neutron Diffraction ◽  
Temperature Structure ◽  
Double Perovskites ◽  
Phase Transition Behavior ◽  
X Ray ◽  
Progressive Loss ◽  
Octahedral Tilting

High temperature synchrotron X-ray and neutron diffraction powder diffraction studies of the uranium perovskites Ba2CaUO6and BaSrCaUO6reveal unusual phase transition behavior associated with the progressive loss of cooperative octahedral tilting.

scholarly journals Sr2Fe1+xRe1−xO6 double perovskites: magnetoresistance and (magneto)thermopower

2019 ◽  
Vol 55 (42) ◽  
pp. 5878-5881 ◽  
Author(s):  
Antoine Maignan ◽  
Christine Martin ◽  
Oleg Lebedev ◽  
Jonas Sottmann ◽  
Lucie Nataf ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Absorption Spectroscopy ◽  
Powder Diffraction ◽  
Double Perovskites ◽  
X Ray ◽  
Transmission Electron ◽  
X Ray Absorption

Polycrystalline Sr2Fe1+xRe1−xO6 samples have been synthesized, structurally characterized by X-ray powder diffraction, transmission electron microscopy, X-ray absorption spectroscopy, and measurements of their magnetotransport properties were performed.

Structural phase transitions and magnetic and spectroscopic properties of the double perovskites Sr2Co1−xMgxTeO6 (x = 0.1, 0.2 and 0.5)

2015 ◽  
Vol 44 (30) ◽  
pp. 13716-13734 ◽  
Author(s):  
B. Orayech ◽  
L. Ortega-San-Martín ◽  
I. Urcelay-Olabarria ◽  
L. Lezama ◽  
T. Rojo ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Phase Transitions ◽  
Structural Phase ◽  
Spectroscopic Properties ◽  
Mode Analysis ◽  
Double Perovskites ◽  
Structural Phase Transitions ◽  
X Ray ◽  
Structural And Magnetic Properties ◽  
Symmetry Mode

Structural and magnetic properties of a series of double perovskites are investigated by X-ray and Neutron diffraction, EPR and magnetic susceptibility. The structural and phase-transitions analysis are done using symmetry mode-analysis approach.

Synthesis and Rietveld refinements of new ceramics Sr2CaFe2WO9 and Sr2PbFe2TeO9 perovskites

2018 ◽  
Vol 33 (2) ◽  
pp. 134-140 ◽  
Author(s):  
Abdelhadi El Hachmi ◽  
Y. Tamraoui ◽  
Bouchaib Manoun ◽  
R. Haloui ◽  
M.A. Elaamrani ◽  
...  
Keyword(s):  
Room Temperature ◽  
Rietveld Analysis ◽  
Double Perovskites ◽  
Unit Cell Parameters ◽  
Rietveld Refinements ◽  
X Ray ◽  
Cell Parameters ◽  
State Technique ◽  
Xrpd Patterns ◽  
Polycrystalline Form

Ceramics of Sr2CaFe2WO9 and Sr2PbFe2TeO9 double perovskites have been prepared in polycrystalline form by solid-state technique, in the air. The crystalline structure was analyzed using X-ray powder diffraction (XRPD) at room temperature. Rietveld analysis of XRPD patterns show that both compounds adopt a tetragonal structure with space group I4/m, with unit cell parameters a = 5.5453(1) Å, c = 7.8389(1) Å for Sr2CaFe2WO9, and a = 5.5994(15) Å, c = 7.8979(30) Å for Sr2PbFe2TeO9. A certain degree of anti-site disordering of W and/or Te and Fe on the B –sites have been detected, indicating the presence of a partial amount of W and/or Te at Fe positions and vice versa.

scholarly journals Controlling Multiple Orderings in Metal Thiocyanate Molecular Perovskites Ax{Ni[Bi(SCN)6]}

2020 ◽  
Author(s):  
Jie Yie Lee ◽  
Sanliang Ling ◽  
Stephen Argent ◽  
Mark Senn ◽  
Laura Cañadillas-Delgado ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Double Perovskites ◽  
Functional Theory ◽  
X Ray ◽  
Vacancy Ordering ◽  
A Site ◽  
Symmetry Mode ◽  
Site Vacancy

<p>We report four new A-site vacancy ordered thiocyanate double double perovskites,</p><p>A1􀀀xfNi[Bi(SCN)6]1􀀀x3 }, A = K<sup>+</sup>, NH4<sup>+</sup>, CH3(NH3)<sup>+</sup> (MeNH<sub>3</sub><sup>+</sup>) and C(NH<sub>2</sub>)<sub>3</sub><sup>+</sup> (Gua<sup>+</sup>), including the first examples of thiocyanate perovskites containing organic A-site cations. We show, using a combination of X-ray and neutron diffraction, that the structure of these frameworks depends on the A-site cation, and that these frameworks possess complex vacancy-ordering patterns and cooperative octahedral tilts distinctly different from atomic perovskites. Density functional theory calculations uncover the energetic origin of these complex orders and allow us to propose a simple rule to predict favoured A-site cation orderings for a given tilt sequence. We use these insights, in combination with symmetry mode analyses, to show that these complex orders offer a new route to non-centrosymmetric perovskites which render them as excellent candidates for</p><p>piezo- and ferroelectric applications.</p>

A Comparison of Pseudomorphic Bcc Phase Stability in Zr/Nb and Ti/Nb Thin Film Multilayers

2004 ◽  
Vol 19 (3) ◽  
pp. 707-715 ◽  
Author(s):  
G.B. Thompson ◽  
R. Banerjee ◽  
S.A. Dregia ◽  
M.K. Miller ◽  
H.L. Fraser
Keyword(s):  
Phase Stability ◽  
Volume Fraction ◽  
Stability Boundary ◽  
Atom Probe ◽  
Bilayer Thickness ◽  
X Ray ◽  
Stability Diagrams ◽  
Phase Stabilization ◽  
Sputter Deposited ◽  
Bcc Phase

A series of Nb-rich Zr/Nb and Ti/Nb multilayers were sputter deposited. Upon a reduction in thickness, a pseudomorphic bcc phase was stabilized in the Zr and Ti layers. X-ray and electron diffraction techniques were used to confirm these phase transformations. The change in phase stability was modeled by the competition between volumetric and interfacial components of the total free energy of a unit bilayer representing the multilayer. An outcome of this model is the ability to plot phase stability diagrams for multilayers, referred to as biphase diagrams, as a function of bilayer thickness and volume fraction. A comparison of the phase stability boundary between hcp/bcc and bcc/bcc for these two systems has shown that the bcc Ti’s pseudomorphic phase stabilization is maintained for a much larger layer thickness as compared to Zr. Atom probe compositional profiles of the Ti/Nb multilayers have indicated that the Nb layers interdiffused into the Ti layers thus helping to facilitate the bcc Ti phase stability in the Ti/Nb multilayers.

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