scholarly journals Thermal and Electric Field-Dependent Evolution of Domain Structures in Polycrystalline BaTiO3 Using the 3D-XRD Technique

2010 ◽  
Vol 2010 ◽  
pp. 1-10 ◽  
Author(s):  
Mesut Varlioglu ◽  
Ulrich Lienert ◽  
Jun-Sang Park ◽  
Jacob L. Jones ◽  
Ersan Üstündag
Keyword(s):  
Electric Field ◽  
Boundary Migration ◽  
Domain Boundary ◽  
Three Dimensional ◽  
Polarization Angle ◽  
X Ray Diffraction ◽  
Domain Structures ◽  
Tetragonal Crystal ◽  
Tetragonal Crystal Structure ◽  
Habit Planes

The evolution of ferroelectric domain structures inside a single grain embedded in a polycrystalline BaTiO3 ceramic was investigated under temperature and electric field using the three-dimensional X-ray diffraction (3D-XRD) method. The orientation of domains within the grain was studied during the phase transformation from the cubic to tetragonal crystal structure. The peak widths broadened from 0.10 ± 0.01∘ to 0.29±0.08∘ along the azimuthal direction during cooling. Four individual tetragonal domain structures were developed from the cubic grain. A twinning model based on {101} habit planes is discussed. While the twinning model predicts 89.47∘ misorientation between 90∘ domains and 1.049∘ misorientation between domain variants, the measured misorientations neither support the twinning model nor are the domain structures mutually orthogonal. The average misorientation of the domain structures at room temperature with respect to the cubic grain was about 0.3∘. Upon application of an electric field, the volume fractions of the domain structures changed systematically favoring growth of domain structures with small polarization angle with respect to applied field direction. No rotation of domain structures was observed upon application of an electric field which is consistent with domain boundary migration.

scholarly journals Characterization of tin dioxide nanoparticles synthesized by oxidation

Cerâmica ◽  
2015 ◽  
Vol 61 (359) ◽  
pp. 328-333 ◽  
Author(s):  
R. C. Abruzzi ◽  
B. A. Dedavid ◽  
M. J. R. Pires
Keyword(s):  
Gas Sensors ◽  
Tin Dioxide ◽  
X Ray Diffraction ◽  
X Ray ◽  
Synthesis Conditions ◽  
Tetragonal Crystal ◽  
Tetragonal Crystal Structure ◽  
Activation Efficiency ◽  
Complementary Techniques

AbstractTin dioxide (SnO2) is a promising material with great potential for applications such as gas sensors and catalysts. Nanostructures of this oxide exhibit greater activation efficiency given their larger effective surface. The present study presents results of the synthesis and characterization of tin dioxide under different conditions via oxidation of solid tin with nitric oxide. SnO2powder was characterized primarily by X-ray diffraction and scanning electron microscopy, as well as complementary techniques such as energy-dispersive X-ray spectroscopy, dynamic light scattering and Fourier transform infrared spectroscopy. The results indicated that the established synthesis conditions were suitable for obtaining rutile tin dioxide nanoparticles with a tetragonal crystal structure.

scholarly journals Piezoelectricity in perovskite-type pseudo-cubic ferroelectrics by partial ordering of off-centered cations

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Yoshihiro Kuroiwa ◽  
Sangwook Kim ◽  
Ichiro Fujii ◽  
Shintaro Ueno ◽  
Yuki Nakahira ◽  
...  
Keyword(s):  
Electric Field ◽  
Applied Electric Field ◽  
Partial Ordering ◽  
Ferroelectric Ceramics ◽  
Piezoelectric Response ◽  
X Ray Diffraction ◽  
Cubic Symmetry ◽  
X Ray ◽  
Domain Structures ◽  
Perovskite Type

Abstract A large piezoelectric response in ferroelectric ceramics is typically associated with extrinsic contributions from ferroelectric domain structures. However, such domain structures cannot be expected in systems with pseudo-cubic symmetry. In this study, we determine the mechanism of significant piezoelectricity and ferroelectricity in 0.3BaTiO3–0.1Bi(Mg1/2Ti1/2)O3–0.6BiFeO3 ceramic with a perovskite-type pseudo-cubic symmetry. Synchrotron radiation X-ray diffraction reveals that the Bi ions in this ceramic essentially prefer to be off-centered at six sites by approximately 0.4 Å, in the cubic <100> directions. A phase transition occurs at TC ~725 K. However, the crystal seems to present a cubic symmetry even at room temperature. The large piezoelectric response is caused by the combinational partial ordering of the off-centered Bi ions, adapted to any direction of the applied electric field to the ceramic grains. The proposed mechanism for the emergence of a high polarization in the above system will enable designing novel Pb-free ceramics by controlling the fluctuated and off-centered ions under an applied electric field.

Studied on Structural Characterization of Lanthanum Doped Barium Titanium Ceramics

2015 ◽  
Vol 819 ◽  
pp. 198-203
Author(s):  
Nur Farahin Abdul Hamid ◽  
Rozana Aina Maulat Osman ◽  
Mohd Sobri Idris ◽  
Tze Qing Tan
Keyword(s):  
Crystal Structure ◽  
Lattice Parameter ◽  
Phase Changes ◽  
X Ray Diffraction ◽  
X Ray ◽  
Tetragonal Crystal ◽  
Tetragonal Crystal Structure ◽  
La Doped ◽  
Conventional Solid State Synthesis

La-doped barium titanate (BaTiO3) was prepared using conventional solid state synthesis route. All peaks for sample x=0 are approaching the phase pure of BaTiO3 structure with tetragonal crystal structure (P4mm). Sintering of pressed powder are performed at 1300oC, 1400oC and 1450oC for overnight for pure BaTiO3 and 1350oC for 3 days for BaTiO3 doped lanthanum with intermittent grinding. Phase transition was studied by different x composition. The changes in the crystal structure of the composition x=0.1 and 0.2 were detected by using X-ray diffraction (XRD). The phase changes between tetragonal-cubic and cubic-tetragonal depending on the temperature. Rietveld Refinement analysis is carried out to determine the lattice parameter and unit cell for BaTiO3.

A method for in-situ measurements of the growth in the bulk of deformed single crystals at the 3DXRD microscope

2004 ◽  
Vol 819 ◽  
Author(s):  
S. Schmidt ◽  
D. Juul Jensen
Keyword(s):  
Spatial Information ◽  
Boundary Migration ◽  
Three Dimensional ◽  
European Synchrotron Radiation Facility ◽  
X Ray Diffraction ◽  
X Ray ◽  
Local Boundary ◽  
Migration Rates ◽  
Spatial Grain

AbstractWith the Three Dimensional X-ray Diffraction microscope (3DXRD) located at the European Synchrotron Radiation Facility (ESRF) full 3D spatial information of grains in the interior of a sample can be measured non-destructively. In this paper we discuss the possibility of an extension to this scenario, namely in-situ annealing studies, where the 3D spatial grain shape can be monitored as function of time. Consequently, local boundary migration rates can be estimated and compared to the deformed microstructure. Such information may reveal to what extend the deformed microstructure influences the growth of a grain during recrystallization.

Synthesis and structural characterization of Ca12Ge17B8O58

2016 ◽  
Vol 71 (11) ◽  
pp. 1141-1146
Author(s):  
Sebastian Bräuchle ◽  
Klaus Wurst ◽  
Hubert Huppertz
Keyword(s):  
Crystal Structure ◽  
High Temperature ◽  
Solid State ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
Open Structure ◽  
X Ray ◽  
Tetragonal Crystal ◽  
Tetragonal Crystal System

AbstractCa12Ge17B8O58 was prepared by high-temperature solid state synthesis at 1100°C in a platinum crucible from calcium carbonate, boric acid, and germanium(IV) oxide. The compound crystallizes in the tetragonal crystal system in the space group P4̅ (No. 81) isotypically to Cd12Ge17B8O58. The structure was refined from single-crystal X-ray diffraction data: a = 15.053(8), c = 4.723(2) Å, V = 1070.2(2) Å3, R1 = 0.0151, and wR2 = 0.0339 for all data. The crystal structure of Ca12Ge17B8O58 consists of [Ge4O12]n chains composed of GeO4 tetrahedra and GeO6 octahedra. The chains are interconnected into a [Ge4O10.5]n network via corner sharing. By additional [Ge(B2O7)4]28– clusters, these units are connected to a three-dimensional [Ge17B8O58]24– framework. The open structure forms three types of tunnels with five-, six-, and seven-membered rings (MRs) along the c axis, where the Ca2+ are located.

Optical and electrical properties of tin oxide-based thin films prepared by streaming process for electrodeless electrochemical deposition

2015 ◽  
Vol 1805 ◽  
Author(s):  
Farnood Khalilzadeh-Rezaie ◽  
Isaiah O. Oladeji ◽  
Gbadebo. T. Yusuf ◽  
Janardan Nath ◽  
Nima Nader ◽  
...  
Keyword(s):  
Thin Films ◽  
Electrochemical Deposition ◽  
Ammonium Fluoride ◽  
Stannic Chloride ◽  
X Ray Diffraction ◽  
Tetragonal Crystal ◽  
Tetragonal Crystal Structure ◽  
Type Semiconductor ◽  
Quartz Substrates ◽  
Substrate Temperatures

ABSTRACTTransparent conducting thin-films of SnO2: F were grown on preheated glass, Al2O3 coated glass, and quartz substrates by Streaming Process for Electrodeless Electrochemical Deposition (SPEED). Stannic chloride (SnCl4) and ammonium fluoride (NH4F) dissolved in a mixture of deionized water and organic solvents were used as precursors. The preheated substrate temperature was varied between 440 and 500 °C. High quality SnO2:F films were grown at all the substrate temperatures studied. The resulting typical film thickness was 250 nm. X-ray diffraction shows that the grown films are polycrystalline SnO2 with a tetragonal crystal structure. The average optical transmission of the films was around 93% throughout the wavelength range 400 to 1000 nm. The lowest electrical resistivity achieved was 6 × 10-4 Ω-cm. The Hall measurements showed that the film is an n-type semiconductor, with carrier mobility of 8.3 cm2/V-s, and carrier concentration of 1 × 1021 cm-3. The direct bandgap was determined to be 4.0 eV from the transmittance spectrum.

A NEW FERROELECTRIC PbZr0.52Ti0.48O3 POLYMORPH OF NANOPARTICLES

2006 ◽  
Vol 20 (04) ◽  
pp. 159-167 ◽  
Author(s):  
S. RAM ◽  
A. MISHRA
Keyword(s):  
Lead Zirconate Titanate ◽  
Ferroelectric Properties ◽  
Lead Zirconate ◽  
Boundary Phase ◽  
Hard Material ◽  
X Ray Diffraction ◽  
Tetragonal Crystal ◽  
Tetragonal Crystal Structure ◽  
Bulk Structure ◽  
20 Nm

Lead-zirconate-titanate PbZr 1-x Ti x O 3 has superb ferroelectric properties in x~0.48 morphotropic phase boundary phase. In bulk form it has a P4mm tetragonal crystal structure of lattice parameters a=0.4036 nm and c=0.4146 nm at room temperature or above, and a Cm monoclinic structure of a=0.5722 nm , b=0.5710 nm , c=0.4137 nm and β=90.50° at lower temperatures. A new polymorph lies in an orthorhombic structure of a=0.4038 nm , b=0.4017 nm , and c=0.4148 nm in small particles of size such as 20 nm. It has an enhanced value of density of 8.033 g/cm3 relative to 8.006 g/cm3 in the tetragonal or 8.000 g/cm3 in the monoclinic bulk structure in a rather incompressible and hard material. The result is analyzed with X-ray diffraction of the sample of nanoparticles.

Imaging of Ferroelectric Domains in KTiOPO4 Single Crystals by Synchrotron X-RAY Topography

1993 ◽  
Vol 310 ◽  
Author(s):  
S. Wang ◽  
M. Dudley ◽  
L.K. Cheng ◽  
J.D. Bierlein ◽  
W. Bindloss
Keyword(s):  
Domain Wall ◽  
Single Crystals ◽  
Long Range ◽  
Domain Walls ◽  
Three Dimensional ◽  
Dynamical Theory ◽  
X Ray Diffraction ◽  
X Ray ◽  
Domain Structures ◽  
Main Components

AbstractThe application of synchrotron white beam X-ray topography to the study of ferroelectric domain structures in hydrothermally grown potassium titanyl phosphate (KTiOPO4: KTP) single crystals is reported. The domain walls can be exclusively imaged on topographs with selected diffraction vectors and X-ray wavelengths, while images of other defects, such as dislocations, inclusions and surface scratches, can be simultaneously made very diffuse. The topographic images correspond well with electrostatic toning images. X-ray topography readily reveals the three dimensional shapes of the domain walls. There are two contributions to domain wall contrast: one is fringe-like which can be interpreted in terms of the dynamical theory of X-ray diffraction, and the other is diffuse strain contrast arising from long range strain associated with the wall. These two contributions can be observed simultaneously or separately depending on the diffraction conditions. The long range strain is thought to be associated with the curvature of the domain walls. It appears that the main components of the displacement field associated with this strain are directed approximately perpendicular to the domain wall.

Structural and optical characterization of Er-doped CaMoO4 down-converting phosphors

2020 ◽  
Vol 76 (5) ◽  
pp. 926-938
Author(s):  
Puneet Kaur ◽  
Rajesh Kumar ◽  
Shreya Davessar ◽  
Atul Khanna
Keyword(s):  
Green Emission ◽  
Unit Cell ◽  
Potential Candidate ◽  
X Ray Diffraction ◽  
Tetragonal Crystal ◽  
Crystal Unit Cell ◽  
Tetragonal Crystal Structure ◽  
Cell Dimensions ◽  
Unit Cell Dimensions ◽  
Er Doped

xEr2O3–(1−x)CaMoO4 (x = 1, 3, 5, 7 and 10 mol%) nanoparticles were synthesized by solid-state sintering at 800°C. X-ray diffraction studies confirmed the tetragonal crystal structure of CaMoO4, while the doped samples show the co-existence of cubic Er2O3 and tetragonal CaMoO4 and rule out the replacement of Ca2+ by Er3+ in the structure. The crystal unit-cell dimensions, phase concentration and atomic position coordinates were determined by Rietveld refinement. The short-range structure of CaMoO4 consists of tetrahedral MoO4 and snub disphenoid deltahedral CaO8 units, while the unit cell of Er2O3 consists of two types of ErO6 octahedral units. All MoO4 units contain Mo—O bonds of equal lengths, whereas two types of slightly different Ca—O bond lengths exist in CaO8. Raman spectra of the doped samples show only Mo—O vibrational modes and the Raman peaks of Er2O3 are masked by Mo—O bond vibrations. CaMoO4 shows bluish-green emission at 500 nm, while Er-doped samples show strong green emission under UV excitation. UV irradiation (380 nm) induces down-conversion green emission at 531 nm and 552 nm and good color purity in 1 mol% Er2O3–CaMoO4 sample which makes it a potential candidate for applications in optical devices.

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