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.

Theoretical and Experimental Study of the Diffraction Contrast on Magnetic Domain Walls

1982 ◽  
Vol 37 (5) ◽  
pp. 419-426 ◽  
Author(s):  
M. Polcarová ◽  
J. Brádler
Keyword(s):  
Experimental Study ◽  
Single Crystals ◽  
Domain Walls ◽  
Magnetic Domain ◽  
Dynamical Theory ◽  
X Ray Diffraction ◽  
X Ray ◽  
Magnetic Domain Walls ◽  
Integrated Intensities ◽  
Good Agreement

Dynamical theory of the X-ray diffraction on a crystal containing misfit boundary was applied to the interpretation of the contrast observed in X-ray topographs on 90° magnetic domain walls in single crystals of an Fe-Si alloy. The integrated intensities were computed for several cases corresponding to the actual conditions of experiments. Good agreement of theoretical and experi­mental results was obtained.

Ferromagnetic Ordering in the Thallide EuPdTl2

2006 ◽  
Vol 61 (2) ◽  
pp. 159-163 ◽  
Author(s):  
Rainer Kraft ◽  
Sudhindra Rayaprol ◽  
C. Peter Sebastian ◽  
Rainer Pöttgen
Keyword(s):  
Curie Temperature ◽  
Single Crystals ◽  
Magnetic Moment ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
Zintl Phase ◽  
X Ray ◽  
Divalent Europium ◽  
Ferromagnetic Ordering

AbstractThe new thallide EuPdTl2, synthesized from the elements in a sealed tantalum tube in a highfrequency furnace, was investigated by X-ray diffraction on powders and single crystals: MgCuAl2 type, Cmcm, Z = 4, a = 446.6(1), b = 1076.7(2), c = 812.0(2) pm, wR2 = 0.0632, 336 F2 values, 16 variables. The structure can be considered as an orthorhombically distorted, palladium-filled variant of the binary Zintl phase EuTl2. The palladium and thallium atoms build up a three-dimensional [PdTl2] polyanion with significant Pd-Tl (286 - 287 pm) and Tl-Tl (323 - 329 pm) interactions. The europium atoms fill distorted hexagonal channels of the [PdTl2] polyanion. Susceptibility measurements show a magnetic moment of 7.46(5) μB/Eu atom, indicative of divalent europium. EuPdTl2 is a soft ferromagnet with a Curie temperature of TC = 12.5(5) K.

X-Ray Diffraction Applied to the Study of Defects in Surfaces

1984 ◽  
Vol 41 ◽  
Author(s):  
I. K. Robinson ◽  
K. L. D'amico
Keyword(s):  
Long Range ◽  
Domain Walls ◽  
Surface Structures ◽  
Long Range Order ◽  
X Ray Diffraction ◽  
X Ray ◽  
Line Defects ◽  
Reconstructed Surface ◽  
Regular Arrays

AbstractThe role of x-ray diffraction in characterising defects in crystals is reviewed briefly. It is most sensitive to the presence of plane defects which destroy the long-range order. The same argument is shown to apply to line defects in surface structures. Two recent glancing incidence x-ray diffraction experiments provide contrasting examples: randomly distributed steps are found in the Au(110) reconstructed surface, while regular arrays of domain walls modify certain phases of krypton monolayers physisorbed on graphite substrates.

Growth and structural and physical properties of diisopropylammonium bromide molecular single crystals

2016 ◽  
Vol 49 (6) ◽  
pp. 2053-2062 ◽  
Author(s):  
Harsh Yadav ◽  
Nidhi Sinha ◽  
Sahil Goel ◽  
Abid Hussain ◽  
Binay Kumar
Keyword(s):  
Single Crystals ◽  
Grown Crystal ◽  
Three Dimensional ◽  
Solution Technique ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dielectric Constant And Loss ◽  
Vis Spectroscopy ◽  
Direct Band ◽  
Crystallographic Axes

Large single crystals of the promising molecular organic ferroelectric diisopropylammonium bromide (DIPAB) have been grown by the solution technique. A structural study was performed using single-crystal X-ray diffraction analysis. The twin element of a selected DIPAB crystal was identified by a morphological study. Intermolecular interactions present in the grown crystal were explored by Hirshfeld surface (three-dimensional) and fingerprint plot (two-dimensional) studies. In UV–vis spectroscopy, the DIPAB crystal has shown high transparency with a wide direct band gap of 5.65 eV. In the photoluminescence spectrum, sharp UV and blue emissions were observed at 370, 392, 417 and 432 nm. The electrical properties were investigated by measuring the dielectric constant (∊) and loss (tanδ) of the grown crystal. The DIPAB crystal exhibits a promising piezoelectric charge coefficient (d33) value of 18 pC N−1, which makes it suitable for transducer applications. A high ferroelectric Curie temperature (Tc≃ 425 K) with high remnant polarization (20.52 µC cm−2) and high coercive field (12.25 kV cm−1) were observed in the as-grown crystal. Vickers microhardness analysis shows that the value of Meyer's index (n= 7.27) belongs to the soft material range, which was also confirmed by void analysis along three crystallographic axes. It is shown that the DIPAB crystal has potential for optical, ferroelectric and piezoelectric applications.

The Stannides EuPdSn and EuPtSn

1996 ◽  
Vol 51 (6) ◽  
pp. 806-810 ◽  
Author(s):  
Rainer Pöttgen
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
Crystal Chemistry ◽  
Three Dimensional ◽  
Type Structure ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray

Abstract EuPdSn and EuPtSn were prepared from the elements in tantalum tubes at 1070 K and investigated by X-ray diffraction on both powder as well as single crystals. They crystallize with the TiNiSi type structure of space group Pnma and with Z = 4 formula units per cell. Both structures were refined from single-crystal diffractometer data: a = 751.24(9), b = 469.15(6), c = 804.31(9) pm, V = 0.2835(1) nm3 for EuPdSn, and a = 753.38(7), b = 467.72(4), c = 793.08(7) pm, V = 0.2795(1) nnr for EuPtSn. The structures consist of three-dimensional [PdSn] and [PtSn] polyanionic networks in which the europium atoms are embedded. The crystal chemistry of these stannides is briefly discussed

scholarly journals Synthesis, crystal structure and charge-distribution validation of a new alluaudite-type phosphate, Na2.22Mn0.87In1.68(PO4)3

2020 ◽  
Vol 76 (8) ◽  
pp. 1369-1372
Author(s):  
Abdessalem Badri ◽  
Inmaculada Alvarez-Serrano ◽  
María Luisa López ◽  
Mongi Ben Amara
Keyword(s):  
Crystal Structure ◽  
Single Crystals ◽  
Three Dimensional ◽  
Structure Type ◽  
X Ray Diffraction ◽  
Flux Method ◽  
X Ray ◽  
Coordination Numbers ◽  
Dimensional Network ◽  
Anionic Framework

Na2.22Mn0.87In1.68(PO4)3, sodium manganese indium tris(phosphate) (2.22/0.87/1.68), was obtained in the form of single crystals by a flux method and was structurally characterized by single-crystal X-ray diffraction. The compound belongs to the alluaudite structure type (space group C2/c) with general formula X(2)X(1)M(1)M(2)2(PO4)3. The X(2) and X(1) sites are partially occupied by sodium [occupancy 0.7676 (17) and 1/2] while the M(1) and M(2) sites are fully occupied within a mixed distribution of sodium/manganese(II) and manganese(II)/indium, respectively. The three-dimensional anionic framework is built up on the basis of M(2)2O10 dimers that share opposite edges with M(1)O6 octahedra, thus forming infinite chains extending parallel to [10\overline{1}]. The linkage between these chains is ensured by PO4 tetrahedra through common vertices. The three-dimensional network thus constructed delimits two types of hexagonal channels, resulting from the catenation of M(2)2O10 dimers, M(1)O6 octahedra and PO4 tetrahedra through edge- and corner-sharing. The channels are occupied by Na+ cations with coordination numbers of seven and eight.

scholarly journals X-ray investigation of lateral hetero-structures of inversion domains in LiNbO3, KTiOPO4and KTiOAsO4

2015 ◽  
Vol 71 (3) ◽  
pp. 255-267 ◽  
Author(s):  
Thomas S. Lyford ◽  
Stephen P. Collins ◽  
Paul F. Fewster ◽  
Pamela A. Thomas
Keyword(s):  
High Resolution ◽  
Domain Wall ◽  
Structure Analysis ◽  
Domain Walls ◽  
A Priori ◽  
Mechanism Analysis ◽  
X Ray Diffraction ◽  
Phase Information ◽  
Correlation Lengths ◽  
X Ray

In this paper periodically domain-inverted (PDI) ferroelectric crystals are studied using high-resolution X-ray diffraction. Rocking curves and reciprocal-space maps of the principal symmetric Bragg reflections in LiNbO3(LN) (Λ = 5 µm), KTiOPO4(KTP) (Λ = 9 µm) and KTiOAsO4(KTA) (Λ = 39 µm) are presented. For all the samples strong satellite reflections were observed as a consequence of the PDI structure. Analysis of the satellites showed that they were caused by a combination ofcoherentandincoherentscattering between the adjacent domains. Whilst the satellites contained phase information regarding the structure of the domain wall, this information could not be rigorously extracted withouta prioriknowledge of the twinning mechanism. Analysis of the profiles reveals strain distributions of Δd/d= 1.6 × 10−4and 2.0 × 10−4perpendicular to domain walls in KTP and LN samples, respectively, and lateral correlation lengths of 63 µm (KTP), 194 µm (KTA) and 10 µm (LN). The decay of crystal truncation rods in LN and KTP was found to support the occurrence of surface corrugations.

scholarly journals Interconversion of multiferroic domains and domain walls

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
E. Hassanpour ◽  
M. C. Weber ◽  
Y. Zemp ◽  
L. Kuerten ◽  
A. Bortis ◽  
...  
Keyword(s):  
Domain Wall ◽  
Physical Properties ◽  
Domain Walls ◽  
Three Dimensional ◽  
Topological Defects ◽  
Long Range Order ◽  
Two Dimensional ◽  
Domain Structures ◽  
Topological Singularities ◽  
Ordered State

AbstractSystems with long-range order like ferromagnetism or ferroelectricity exhibit uniform, yet differently oriented three-dimensional regions called domains that are separated by two-dimensional topological defects termed domain walls. A change of the ordered state across a domain wall can lead to local non-bulk physical properties such as enhanced conductance or the promotion of unusual phases. Although highly desirable, controlled transfer of these properties between the bulk and the spatially confined walls is usually not possible. Here, we demonstrate this crossover by confining multiferroic Dy0.7Tb0.3FeO3 domains into multiferroic domain walls at an identified location within a non-multiferroic environment. This process is fully reversible; an applied magnetic or electric field controls the transformation. Aside from expanding the concept of multiferroic order, such interconversion can be key to addressing antiferromagnetic domain structures and topological singularities.

Ternary Indides LnRhIn2 (Ln = La, Ce, Pr, Nd, Sm) with MgCuAl2 Type Structure

2002 ◽  
Vol 57 (7) ◽  
pp. 798-802 ◽  
Author(s):  
Vasyl’ I Zaremba ◽  
Vitaliy P Dubenskiy ◽  
Rainer Pöttgena
Keyword(s):  
Single Crystals ◽  
Three Dimensional ◽  
Argon Atmosphere ◽  
Type Structure ◽  
Subsequent Annealing ◽  
X Ray Diffraction ◽  
Interatomic Distances ◽  
X Ray ◽  
Arc Melting ◽  
Trigonal Prisms

The ternary indides LnRhIn2 (Ln = La, Ce, Pr, Nd, Sm) were synthesized by arc-melting of the elements under an argon atmosphere and subsequent annealing at 870 K. The samples have been investigated by X-ray diffraction on powders and single crystals: MgCuAl2 type, Cmcm, a = 448.2(1), b = 1025.7(1), c = 795.1(1) pm, wR2 = 0.0372, 228 F2 values, 16 variables for LaRhIn2, a = 446.0(1), b = 1017.3(2), c = 792.7(1) pm for CeRhIn2, a = 444.03(6), b = 1013.1(1), c = 792.5(1) pm for PrRhIn2, a = 442.49(5), b = 1012.7(1), c = 789.3(1) pm for NdRhIn2, and a = 438.1(1), b = 1009.3(1), c = 788.3(1) pm, wR2= 0.0414, 304 F2 values, 16 variables for SmRhIn2. Geometrical motifs of these structures are tricapped trigonal prisms around the rhodium atoms. The shortest interatomic distances were observed for the Rh-In contacts: 280-282 pm for LaRhIn2 and 276-279 pm for SmRhIn2. Together, the rhodium and indium atoms build a three-dimensional [RhIn2] polyanion in which the lanthanoid atoms fill distorted pentagonal channels. According to one short La-Rh (282 pm) and Sm-Rh (284 pm) distance one can assume strong bonding of the lanthanoid atoms to the polyanion.

Single-crystal x-ray diffraction structures of covalent organic frameworks

Science ◽  
2018 ◽  
Vol 361 (6397) ◽  
pp. 48-52 ◽  
Author(s):  
Tianqiong Ma ◽  
Eugene A. Kapustin ◽  
Shawn X. Yin ◽  
Lin Liang ◽  
Zhengyang Zhou ◽  
...  
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
Diffraction Data ◽  
General Procedure ◽  
Three Dimensional ◽  
Electron Diffraction Data ◽  
Covalent Organic Frameworks ◽  
X Ray Diffraction ◽  
X Ray

The crystallization problem is an outstanding challenge in the chemistry of porous covalent organic frameworks (COFs). Their structural characterization has been limited to modeling and solutions based on powder x-ray or electron diffraction data. Single crystals of COFs amenable to x-ray diffraction characterization have not been reported. Here, we developed a general procedure to grow large single crystals of three-dimensional imine-based COFs (COF-300, hydrated form of COF-300, COF-303, LZU-79, and LZU-111). The high quality of the crystals allowed collection of single-crystal x-ray diffraction data of up to 0.83-angstrom resolution, leading to unambiguous solution and precise anisotropic refinement. Characteristics such as degree of interpenetration, arrangement of water guests, the reversed imine connectivity, linker disorder, and uncommon topology were deciphered with atomic precision—aspects impossible to determine without single crystals.

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