Ordered Structures in Ba(Cd1/3Ta2/3)O3 Microwave Ceramics: A Transmission Electron Microscopy Study

2003 ◽  
Vol 783 ◽  
Author(s):  
J. Sun ◽  
S. J. Liu ◽  
N. Newman ◽  
David. J. Smith
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Domain Size ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Microwave Ceramics ◽  
Ordered Structures ◽  
Domain Structures ◽  
Transmission Electron ◽  
Average Domain Size

ABSTRACTOrdered structures of Ba(Cd1/3Ta2/3)O3 ceramics with and without boron additive were investigated systemically by electron diffraction and high resolution transmission electron microscopy. The results showed a well-ordered structure of 1:2 with hexagonal symmetry for Ba(Cd1/3Ta2/3)O3 with boron additive. No significant changes in ordered structures were observed after long-period annealing. The 1:2 ordered domain structures (average domain size ∼18 nm) and high-density domain boundaries induced by ordering were observed for Ba(Cd1/3Ta2/3)O3 without boron additive sintered at relatively high temperature. The sintering process has a profound influence on the microstructure of Ba(Cd1/3Ta2/3)O3 ceramics.

Transmission electron microscopy study of domain structures in ferroelectric SrBi2Nb2O9 ceramics

2004 ◽  
Vol 839 ◽  
Author(s):  
C. Karthik ◽  
N. Ravishankar ◽  
K.B.R. Varma
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Ferroelectric Ceramics ◽  
Potential Candidate ◽  
Transmission Electron Microscopy Study ◽  
Antiphase Boundaries ◽  
Domain Structures ◽  
Transmission Electron

ABSTRACTA transmission electron microscopy study has been carried out on the domain structures of SrBi2Nb2O9 (SBN) ferroelectric ceramics which belong to the Aurivillius family of bismuth layered perovskite oxides. SBN is a potential candidate for Ferroelectric Random access memory (FeRAM) applications. The 90° ferroelectric domains and antiphase boundaries (APBs) were identified with dark field imaging techniques using different superlattice reflections which arise as a consequence of octahedral rotations and cationic shifts. The 90° domain walls are irregular in shape without any faceting. The antiphase boundaries are less dense compared to that of SrBi2Ta2O9(SBT). The electron microscopy observations are correlated with the polarization fatigue nature of the ceramic where the domain structures possibly play a key role in the fatigue- free behavior of the Aurivillius family of ferroelectric oxides.

scholarly journals Transmission Electron Microscopy Study of Domain Structures in Multiferroic BiFeO3 Thin Films

2010 ◽  
Vol 16 (S2) ◽  
pp. 1396-1397
Author(s):  
CT Nelson ◽  
Y Zhang ◽  
CM Folkman ◽  
CB Eom ◽  
X Pan
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Transmission Electron Microscopy Study ◽  
Domain Structures ◽  
Bifeo3 Thin Films ◽  
Transmission Electron ◽  
Multiferroic Bifeo3

Extended abstract of a paper presented at Microscopy and Microanalysis 2010 in Portland, Oregon, USA, August 1 – August 5, 2010.

TRANSMISSION ELECTRON MICROSCOPY STUDY OF TWIN DOMAIN STRUCTURES IN YBa2Cu3O7−x SUPERCONDUCTOR

1988 ◽  
Vol 01 (11n12) ◽  
pp. 443-453
Author(s):  
LIYING CAI ◽  
GANGKAI ZHAO ◽  
MEIJUAN ZHAO ◽  
MEIZHEN ZHANG ◽  
XIAOWEN ZHANG
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Domain Boundary ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Twin Domain ◽  
Domain Structures ◽  
Transmission Electron ◽  
Diffraction Patterns ◽  
Lattice Planes

The study of the twin domain structure of YBa2Cu3O7−x superconductor synthesized by coprecipitation method has been carried out by using the transmission electron microscopy. It was found that the twin domain boundary was parallel to the (110) lattice planes. The twin domain is designated as a 90° one. The same twin structure exhibited different characteristics of spot splitting in its selected area eletron diffraction patterns (SADP) when it was irradiated in different incidence directions. The experimental results were satisfactorily consistent with the theoretical calculation. The mechanism of the formation of 90° twin domain has also been discussed. The phase transformation from tetragonal to orthorhombic taking place in YBa2Cu3O7−x ceramics during cooling is considered to be of the “Martensite”.

TEMPERATURE DEPENDENCE OF THE MICROSTRUCTURE IN YBa2Cu3Oy: TRANSMISSION ELECTRON MICROSCOPY STUDY

1990 ◽  
Vol 04 (06) ◽  
pp. 399-407
Author(s):  
J. Q. LI ◽  
Z. X. ZHAO ◽  
F. H. LI ◽  
D. Y. YANG ◽  
G. S. SHI
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Tetragonal Phase ◽  
Structural Phase ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Transmission Electron Microscopy Study ◽  
Domain Structures ◽  
Transmission Electron ◽  
Superconducting Compound

A transmission electron microscopy study has confirmed some new features of thermal variations of the microstructure in the high-T c superconducting compound YBa 2 Cu 3 O y. The changes of domain structures and the nucleation process of the tetragonal phase with the increase of temperature are demonstrated by series of images taken under in-situ heating observations. At temperature near 250°C, two new sets of planar defects have been observed along the directions of a and b-axes, respectively. It has been identified that a continuous structural phase transition, from orthorhombic to tetragonal phase, occurs at about 480 °C. The structural properties of the tetragonal phase have been studied at 700°C.

Transmission Electron Microscopy study of Bi-based superconducting phases

1990 ◽  
Vol 48 (4) ◽  
pp. 50-51
Author(s):  
J.G. Wen ◽  
K.K. Fung
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Single Crystals ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Space Groups ◽  
Superconducting Phases ◽  
Ceramic Samples ◽  
Transmission Electron ◽  
Modulated Structures

Bi-based superconducting phases have been found to be members of a structural series represented by Bi2Sr2Can−1Cun−1On+4, n=1,2,3, and are referred to as 2201, 2212, 2223 phases. All these phases are incommensurate modulated structures. The super space groups are P2/b, NBbmb 2201, 2212 phases respectively. Pb-doped ceramic samples and single crystals and Y-doped single crystals have been studied by transmission electron microscopy.Modulated structures of all Bi-based superconducting phases are in b-c plane, therefore, it is the best way to determine modulated structure and c parameter in diffraction pattern. FIG. 1,2,3 show diffraction patterns of three kinds of modulations in Pb-doped ceramic samples. Energy dispersive X-ray analysis (EDAX) confirms the presence of Pb in the three modulated structures. Parameters c are 3 0.06, 38.29, 30.24Å, ie 2212, 2223, 2212 phases for FIG. 1,2,3 respectively. Their average space groups are all Bbmb.

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