Lattice distortions in one-dimensional Ising chains

1974 ◽  
Vol 10 (5) ◽  
pp. 2039-2043 ◽  
Author(s):  
E. Pytte
Keyword(s):  
One Dimensional ◽  
Lattice Distortions

scholarly journals Polar state induced by block-type lattice distortions in BaFe2Se3 with quasi-one-dimensional ladder structure

2019 ◽  
Vol 99 (24) ◽  
Author(s):  
Takuya Aoyama ◽  
Satoshi Imaizumi ◽  
Takuya Togashi ◽  
Yoshifumi Sato ◽  
Kazuki Hashizume ◽  
...  
Keyword(s):  
Block Type ◽  
Ladder Structure ◽  
One Dimensional ◽  
Polar State ◽  
Lattice Distortions ◽  
Type Lattice

Observation of a high-temperature incommensurate phase transition and discommensurations in TaTe4

1991 ◽  
Vol 49 ◽  
pp. 566-567
Author(s):  
J.C. Bennett ◽  
F.W. Boswell ◽  
S. Ritchie ◽  
J.M. Corbett ◽  
A. Prodan
Keyword(s):  
Crystal Structure ◽  
Room Temperature ◽  
Dark Field ◽  
Charge Density Waves ◽  
Full Spectrum ◽  
One Dimensional ◽  
Sdf Imaging ◽  
Metal Atoms ◽  
Lattice Distortions ◽  
Dimensional Crystal

In many ways, TaTe4 and NbTe4 are nearly prototypical compounds for the study of charge-density waves (CDW). The compounds have a quasi-one-dimensional crystal structure in which chains of metal atoms are centered within extended cages of Te atoms in square antiprismatic coordination. The observed lattice distortions, involving mainly longitudinal motions of the metal atoms along the chains, correspond to that of the classic CDW model. In addition, the compounds exhibit the full spectrum of possible CDW-driven phase transitions: commensurate-to-incommensurate (C to IC), C to C and IC to IC. The subcell of TaTe4 is tetragonal with axes (a x a x c). At room temperature, the crystal is commensurately modulated giving rise to a supercell with axes (2a x 2a x 3c) and, upon heating, has been observed to undergo a C to C transition at about 450 K. In this paper, we report an additional C to IC transition occurring above 550 K. The evolution of the microstructure upon heating, including the formation of discommensuration arrays in the IC state, has been revealed by satellite dark-field (SDF) imaging.

Calculation of diffuse scattering near Bragg reflections from coherent precipitates

1988 ◽  
Vol 3 (2) ◽  
pp. 267-273 ◽  
Author(s):  
S. Iida ◽  
B. C. Larson ◽  
J. Z. Tischler
Keyword(s):  
Size Distribution ◽  
Diffuse Scattering ◽  
Higher Order ◽  
Internal Strain ◽  
Numerical Calculations ◽  
One Dimensional ◽  
Direct Scattering ◽  
Lattice Distortions ◽  
Dilute Alloy

Numerical calculations of the diffuse scattering near Bragg reflections from coherent solute precipitates in a dilute alloy have been made. Results are presented for spherical precipitates in an elastically isotropic continous medium where the calculations have been reduced to a one-dimensional numerical integral. The scattering is separated into direct scattering from the precipitates, the Huang scattering from the lattice distortions, and the higher-order distortion scattering; calculations are presented for 50 Å radius precipitates with an internal strain of – 1.5%, and the sensitivity of the scattering to changes of the size and the internal strain of the precipitates is demonstrated. The possibility of using such scattering for the determination of the concentration, size distribution, and internal strain of solute precipitates is discussed.

A one-dimensional self-gravitating stellar gas

1966 ◽  
Vol 25 ◽  
pp. 46-48 ◽  
Author(s):  
M. Lecar
Keyword(s):  
Gravitational Field ◽  
Phase Space ◽  
Motion Picture ◽  
Space Distribution ◽  
Two Dimensional ◽  
One Dimensional ◽  
Phase Space Distribution ◽  
Dimensional Phase Space ◽  
The Mean

“Dynamical mixing”, i.e. relaxation of a stellar phase space distribution through interaction with the mean gravitational field, is numerically investigated for a one-dimensional self-gravitating stellar gas. Qualitative results are presented in the form of a motion picture of the flow of phase points (representing homogeneous slabs of stars) in two-dimensional phase space.

Electron-Mirror Microscopic Aspects of Ferroelectric Domains of BaTiO3 And Ca2Sr (C2H5CO2)6

1970 ◽  
Vol 28 ◽  
pp. 478-479
Author(s):  
Teruo Someya ◽  
Jinzo Kobayashi
Keyword(s):  
Surface Layer ◽  
Electric Fields ◽  
Quantitative Study ◽  
Recent Progress ◽  
Ferroelectric Domain ◽  
Resolving Power ◽  
Surface Pattern ◽  
Crystal Surfaces ◽  
One Dimensional ◽  
Ferroelectric Domains

Recent progress in the electron-mirror microscopy (EMM), e.g., an improvement of its resolving power together with an increase of the magnification makes it useful for investigating the ferroelectric domain physics. English has recently observed the domain texture in the surface layer of BaTiO3. The present authors ) have developed a theory by which one can evaluate small one-dimensional electric fields and/or topographic step heights in the crystal surfaces from their EMM pictures. This theory was applied to a quantitative study of the surface pattern of BaTiO3).

Structure and function of neural networks in the retina

1988 ◽  
Vol 46 ◽  
pp. 26-27
Author(s):  
Peter Sterling
Keyword(s):  
Ganglion Cells ◽  
Three Dimensional ◽  
Structure And Function ◽  
Synaptic Connections ◽  
Visual Axis ◽  
One Dimensional ◽  
Cat Retina ◽  
Ultrathin Sections ◽  
And Function ◽  
Insight Into

The synaptic connections in cat retina that link photoreceptors to ganglion cells have been analyzed quantitatively. Our approach has been to prepare serial, ultrathin sections and photograph en montage at low magnification (˜2000X) in the electron microscope. Six series, 100-300 sections long, have been prepared over the last decade. They derive from different cats but always from the same region of retina, about one degree from the center of the visual axis. The material has been analyzed by reconstructing adjacent neurons in each array and then identifying systematically the synaptic connections between arrays. Most reconstructions were done manually by tracing the outlines of processes in successive sections onto acetate sheets aligned on a cartoonist's jig. The tracings were then digitized, stacked by computer, and printed with the hidden lines removed. The results have provided rather than the usual one-dimensional account of pathways, a three-dimensional account of circuits. From this has emerged insight into the functional architecture.

Intergrowth of modulated structures in high Tc Bi-Sr-Ca-Cu-O superconductors

1990 ◽  
Vol 48 (4) ◽  
pp. 76-77
Author(s):  
A.Q. He ◽  
G.W. Qiao ◽  
J. Zhu ◽  
H.Q. Ye
Keyword(s):  
Twin Structure ◽  
Modulated Structure ◽  
High Tc ◽  
One Dimensional ◽  
Lattice Constants ◽  
Superconducting Phases ◽  
Modulated Structures ◽  
Layer Structures

Since the first discovery of high Tc Bi-Sr-Ca-Cu-O superconductor by Maeda et al, many EM works have been done on it. The results show that the superconducting phases have a type of ordered layer structures similar to that in Y-Ba-Cu-O system formulated in Bi2Sr2Can−1CunO2n+4 (n=1,2,3) (simply called 22(n-1) phase) with lattice constants of a=0.358, b=0.382nm but the length of c being different according to the different value of n in the formulate. Unlike the twin structure observed in the Y-Ba-Cu-O system, there is an incommensurate modulated structure in the superconducting phases of Bi system superconductors. Modulated wavelengths of both 1.3 and 2.7 nm have been observed in the 2212 phase. This communication mainly presents the intergrowth of these two kinds of one-dimensional modulated structures in 2212 phase.

Electronic structure studies of conducting polymers by electron energy-loss spectroscopy

1996 ◽  
Vol 54 ◽  
pp. 160-161
Author(s):  
J. Fink
Keyword(s):  
Electronic Structure ◽  
Conducting Polymers ◽  
Conjugated Polymers ◽  
Electron Acceptors ◽  
Electron Donors ◽  
Light Emitting ◽  
One Dimensional ◽  
New Class ◽  
Electrical Conductivities ◽  
Electron Energy Loss

Conducting polymers comprises a new class of materials achieving electrical conductivities which rival those of the best metals. The parent compounds (conjugated polymers) are quasi-one-dimensional semiconductors. These polymers can be doped by electron acceptors or electron donors. The prototype of these materials is polyacetylene (PA). There are various other conjugated polymers such as polyparaphenylene, polyphenylenevinylene, polypoyrrole or polythiophene. The doped systems, i.e. the conducting polymers, have intersting potential technological applications such as replacement of conventional metals in electronic shielding and antistatic equipment, rechargable batteries, and flexible light emitting diodes.Although these systems have been investigated almost 20 years, the electronic structure of the doped metallic systems is not clear and even the reason for the gap in undoped semiconducting systems is under discussion.

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