Real domain structure in orthorhombic phase of NaNbO3 crystals

ABSTRACTThe orthorhombic compound Ru2Si3 is currently of interest as a high-temperature thermoelectric material. In order to clarify the effects of crystal orientation on the thermoelectric properties of Ru2Si3, we have examined the microstructure, Seebeck coefficient, electrical resistivity, and thermal conductivity of Ru2Si3 along the three principal axes, using these measured quantities to describe the relative thermoelectric performance as a property of crystal orientation. Ru2Si3 undergoes a high temperature (HT)→low temperature (LT) phase change and polycrystalline Si platelet precipitation during cooling, both of which are expected to effect the thermoelectric properties. The HT tetragonal→LT orthorhombic phase transformation results in a [010]//[010], [100]//[001] two-domain structure, while polycrystalline Si precipitation occurs on the (100)LT and (001)LT planes. The [010] orientation is found to posses superior thermoelectric properties (with the dimensionless figure of merit, ZT[010]/ZT[100]>4 at 650°C), due principally to the larger Seebeck coefficient along the [010] direction. The effect of the domain structure on the thermoelectric properties is discussed.

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Study of domain configurations in (Bi,Na)ZrO3-modified (K,Na)(Nb,Sb)O3 piezoelectric ceramics by acid-etching at different temperatures

Scientific Reports ◽

10.1038/s41598-020-75593-6 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Jialiang Zhang ◽

Chunming Zhou

Keyword(s):

Domain Structure ◽

Orthorhombic Phase ◽

Underlying Mechanism ◽

Ferroelectric Ceramic ◽

Acid Etching ◽

Mathematical Basis ◽

Etching Technique ◽

Different Temperatures ◽

Nanodomain Structure ◽

Piezoelectric Performance

Abstract Domain structure often greatly affects piezoelectric performance of a ferroelectric ceramic. Accordingly, a convenient method that can well characterize the domain structure at various temperatures is highly desired for understanding the underlying mechanism. An improved acid-etching technique was recently developed for such purpose. Domain structure of poled 0.96(K0.48Na0.52)(Nb0.96Sb0.04)O3–0.04(Bi0.50Na0.50)ZrO3 ceramics with a large piezoelectric coefficient d33 of 535 pC/N was systematically investigated at three typical temperatures. It was found that domain configurations change significantly with temperature. Hierarchical nanodomain structure is widely observed in domain patterns acid-etched at 25 °C, due to the orthorhombic-tetragonal phase coexistence. By contrast, the majority part of those acid-etched at − 60 °C are simply some long parallel stripes, while a small amount of banded structure appears in broad stripes inside some grains. A nearly 63° intersectional angle is seen between two adjacent sets of parallel stripes in the domain pattern of a cuboid-shaped grain, indicating that orthorhombic phase remains down to − 60 °C. The domain patterns acid-etched at 80 °C become even simpler, mainly consisting of long parallel stripes that are several hundred nanometers wide and have quite straight edges. Fundamental issues associating with the possible domain configurations and the acid-etching were discussed on the simple mathematical basis.

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Domain-structure relaxation in the tetragonal-to-orthorhombic phase transition of the layered perovskiteSr1.8La0.2Mn1−yFeyO4

Physical Review B ◽

10.1103/physrevb.75.104416 ◽

2007 ◽

Vol 75 (10) ◽

Cited By ~ 9

Author(s):

Wataru Norimatsu ◽

Yasumasa Koyama

Keyword(s):

Phase Transition ◽

Domain Structure ◽

Orthorhombic Phase ◽

Structure Relaxation

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Electromechanical behaviour of PZT with real domain structure

Computational Materials Science ◽

10.1016/j.commatsci.2007.05.005 ◽

2008 ◽

Vol 41 (3) ◽

pp. 420-429 ◽

Cited By ~ 9

Author(s):

S. Anteboth ◽

A. Brückner-Foit ◽

M.J. Hoffmann ◽

U. Sutter ◽

Th. Schimmel ◽

...

Keyword(s):

Domain Structure ◽

Real Domain

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Videographic reconstructions and simulations of the real Cu3Au structure at various temperatures

Zeitschrift für Kristallographie - Crystalline Materials ◽

10.1524/zkri.1994.209.4.315 ◽

1994 ◽

Vol 209 (4) ◽

Cited By ~ 1

Author(s):

S. H. Rahman

Keyword(s):

Domain Structure ◽

Simulation Method ◽

The Real ◽

Real Domain ◽

Structure Configuration

AbstractApplying the videographic reconstruction and simulation method, the real domain structure configuration of the Cu

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Domains and domain nucleation in magnetron-sputtered CoCr thin films

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100151064 ◽

1993 ◽

Vol 51 ◽

pp. 1046-1047

Author(s):

B. G. Demczyk

Keyword(s):

Thin Films ◽

Domain Structure ◽

Magnetic Domain ◽

Domain Size ◽

Film Plane ◽

Magnetic Domain Structure ◽

Perpendicular Magnetization ◽

Columnar Grains ◽

Reversal Mechanism ◽

Lorentz Transmission Electron Microscopy

CoCr thin films have been of interest for a number of years due to their strong perpendicular anisotropy, favoring magnetization normal to the film plane. The microstructure and magnetic properties of CoCr films prepared by both rf and magnetron sputtering have been examined in detail. By comparison, however, relatively few systematic studies of the magnetic domain structure and its relation to the observed film microstructure have been reported. In addition, questions still remain as to the operative magnetization reversal mechanism in different film thickness regimes. In this work, the magnetic domain structure in magnetron sputtered Co-22 at.%Cr thin films of known microstructure were examined by Lorentz transmission electron microscopy. Additionally, domain nucleation studies were undertaken via in-situ heating experiments.It was found that the 50 nm thick films, which are comprised of columnar grains, display a “dot” type domain configuration (Figure 1d), characteristic of a perpendicular magnetization. The domain size was found to be on the order of a few structural columns in diameter.

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Twin boundary structure of a Y-Ba-Cu-O superconductor

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100152811 ◽

1989 ◽

Vol 47 ◽

pp. 168-169

Author(s):

Yimei Zhu ◽

Masaki Suenaga ◽

R. L. Sabatini ◽

Youwen Xu

Keyword(s):

Twin Boundary ◽

Fine Particles ◽

Imaging Techniques ◽

Fine Powder ◽

Orthorhombic Phase ◽

Boundary Structure ◽

Crystallographic Axis ◽

System A ◽

High Resolution Structure ◽

Electron Microscopes

The (110) twin structure of YBa2Cu3O7 superconductor oxide, which is formed to reduce the strain energy of the tetragonal to orthorhombic phase transformation by alternating the a-b crystallographic axis across the boundary, was extensively investigated. Up to now the structure of the twin boundary still remained unclear. In order to gain insight into the nature of the twin boundary in Y-Ba-Cu-O system, a study using electron diffraction techniques including optical and computed diffractograms, as well as high resolution structure imaging techniques with corresponding computer simulation and processing was initiated.Bulk samples of Y-Ba-Cu-O oxide were prepared as described elsewhere. TEM specimens were produced by crushing bulk samples into a fine powder, dispersing the powder in acetone, and suspending the fine particles on a holey carbon grid. The electron microscopy during this study was performed on both a JEOL 2000EX and 2000FX electron microscopes operated at 200 kV.

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