Analytic dependence of the Madelung constant on lattice parameters for 2D and 3D metal diiodides (MI<sub>2</sub>) with CdI<sub>2</sub> (2H polytype) layered structure

The Al2O3-3D-ceramics' structure changing when sintering

NOVYE OGNEUPORY (NEW REFRACTORIES) ◽

10.17073/1683-4518-2018-9-35-39 ◽

2018 ◽

pp. 35-39 ◽

Cited By ~ 1

Author(s):

S. P. Bogdanov ◽

M. M. Sychev ◽

L. A. Lebedev

Keyword(s):

3D Printing ◽

Crystal Lattice ◽

Layered Structure ◽

Lattice Parameters ◽

Grain Structure ◽

3D Printed ◽

Crystal Lattice Parameters

It was proposed to regard the ceramic products with periodic topology as the systems having the multilevel organized structures. The development of the structure was studied at diﬀerent scales levels after the sintering at 1700 °С for the corundum ceramics prepared by 3D-printing. The peculiarities of the geometry change were shown for the 3d-printed layered structure, for the material's grain structure and for the crystal lattice parameters of the α-Al2O3grains.Ill. 5. Ref.8.

Download Full-text

Investigation of structure and electrochemical properties of layered structure NaFexMn1-xO2

Science and Technology Development Journal - Natural Sciences ◽

10.32508/stdjns.v3i4.573 ◽

2020 ◽

Vol 3 (4) ◽

pp. 317-325

Author(s):

Nguyen Thi Kieu Duyen ◽

Huynh Le Thanh Nguyen ◽

Nguyen Thi Thu Trang ◽

Le My Loan Phung ◽

Tran Van Man

Keyword(s):

Layered Structure ◽

Electrode Materials ◽

Low Cost ◽

Specific Capacity ◽

Rechargeable Batteries ◽

Lattice Parameters ◽

Constant Current ◽

Metallic Sodium ◽

Layered Oxides ◽

Unit Cells

Layered oxides are promising electrode materials for sodium-ion batteries, the next generation of rechargeable batteries. The layered oxides with the tránition metallic manganese and iron have paid more attention due to its low-cost, eco-friendly, and facile preparation. In this work, the metallic sodium oxides with a layered structure based on Fe and Mn, NaFexMn1-xO2 (x = 1/3, 1/2 và 2/3) were synthesized via a solid-state reaction at 900 oC for 12–36 hours. All XRD patterns of NaFexMn1-xO2 pointed out the layered structure. In two ratio Fe:Mn = 1/3:2/3 and 1/2:1/2, the synthesized samples presented the P3-layered structure, while in ratio Fe:Mn = 2/3:1/3, the O3-structure was obtained. The lattice parameters were determined by Celref software. The lattice parameters and the volumic of unit cells depended on the ionic radius of cation Mn3+ and Fe3+. The Na-migration was studied by the cycling test with a constant current. The charge-discharge curves and the specific capacity depended on the ratio of Fe:Mn. The specific capacity was found out 120 mAh/g (1/2:1/2), 118 mAh/g (2/3:1/3), and 120 mAh/g (1/3:2/3). After 20 cycles, the capacity was maintained 77 mAh/g (1/2:1/2), 88 mAh/g (2/3:1/3), and 80 mAh/g (1/3:2/3).

Download Full-text

Analysis of 2D and 3D defects associated with precipitation of Cu in silicon

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010008866x ◽

1991 ◽

Vol 49 ◽

pp. 870-871

Author(s):

P.M. Rice ◽

MJ. Kim ◽

R.W. Carpenter

Keyword(s):

Colony Growth ◽

Dark Field ◽

Dark Side ◽

Silicide Phase ◽

Strain Fields ◽

Near Surface ◽

Unknown Composition ◽

Secondary Precipitates ◽

20 Nm ◽

2D And 3D

Extrinsic gettering of Cu on near-surface dislocations in Si has been the topic of recent investigation. It was shown that the Cu precipitated hetergeneously on dislocations as Cu silicide along with voids, and also with a secondary planar precipitate of unknown composition. Here we report the results of investigations of the sense of the strain fields about the large (~100 nm) silicide precipitates, and further analysis of the small (~10-20 nm) planar precipitates.Numerous dark field images were analyzed in accordance with Ashby and Brown's criteria for determining the sense of the strain fields about precipitates. While the situation is complicated by the presence of dislocations and secondary precipitates, micrographs like those shown in Fig. 1(a) and 1(b) tend to show anomalously wide strain fields with the dark side on the side of negative g, indicating the strain fields about the silicide precipitates are vacancy in nature. This is in conflict with information reported on the η'' phase (the Cu silicide phase presumed to precipitate within the bulk) whose interstitial strain field is considered responsible for the interstitial Si atoms which cause the bounding dislocation to expand during star colony growth.

Download Full-text

In situ TEM Studies of agglomeration of sub-nanometer Ru layers in Ru/C multilayers

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100121685 ◽

1992 ◽

Vol 50 (1) ◽

pp. 256-257

Author(s):

Tai D. Nguyen ◽

Ronald Gronsky ◽

Jeffrey B. Kortright

Keyword(s):

Layered Structure ◽

Driving Force ◽

High Energy ◽

Superior Performance ◽

In Situ Tem ◽

Rayleigh Instability ◽

Practical Applications ◽

Transmission Electron ◽

Diffraction Patterns

Nanometer period Ru/C multilayers are one of the prime candidates for normal incident reflecting mirrors at wavelengths < 10 nm. Superior performance, which requires uniform layers and smooth interfaces, and high stability of the layered structure under thermal loadings are some of the demands in practical applications. Previous studies however show that the Ru layers in the 2 nm period Ru/C multilayer agglomerate upon moderate annealing, and the layered structure is no longer retained. This agglomeration and crystallization of the Ru layers upon annealing to form almost spherical crystallites is a result of the reduction of surface or interfacial energy from die amorphous high energy non-equilibrium state of the as-prepared sample dirough diffusive arrangements of the atoms. Proposed models for mechanism of thin film agglomeration include one analogous to Rayleigh instability, and grain boundary grooving in polycrystalline films. These models however are not necessarily appropriate to explain for the agglomeration in the sub-nanometer amorphous Ru layers in Ru/C multilayers. The Ru-C phase diagram shows a wide miscible gap, which indicates the preference of phase separation between these two materials and provides an additional driving force for agglomeration. In this paper, we study the evolution of the microstructures and layered structure via in-situ Transmission Electron Microscopy (TEM), and attempt to determine the order of occurence of agglomeration and crystallization in the Ru layers by observing the diffraction patterns.

Download Full-text

Misfit Dislocations in the Ilmenite (FeTiO3)-Hematite (Fe2O3) System

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s1431927600000921 ◽

1980 ◽

Vol 38 ◽

pp. 212-213 ◽

Cited By ~ 1

Author(s):

K.P.D. Lagerlöf ◽

A.H. Heuer ◽

T.E. Mitchell

Keyword(s):

Misfit Dislocation ◽

Lattice Parameters ◽

Dislocation Network ◽

Misfit Dislocations ◽

Space Group ◽

Two Phases ◽

Hematite Fe2o3

It has been reported by Lally et. al. [1] that precipitates of hematite (Fe2O3, space group R3c) in a matrix of ilmenite (FeTiO3, space group R3) are lens shaped and flattened along the [0001]-direction. The coherency across the interface is lost by the introduction of a misfit dislocation network, which minimizes the strain due to the deviation in lattice parameters between the two phases [2]. The purpose of this paper is to present a new analysis of this network.

Download Full-text

Covalent organic frameworks: an ideal platform for designing ordered materials and advanced applications

Chemical Society Reviews ◽

10.1039/d0cs00620c ◽

2021 ◽

Author(s):

Ruoyang Liu ◽

Ke Tian Tan ◽

Yifan Gong ◽

Yongzhi Chen ◽

Zhuoer Li ◽

...

Keyword(s):

Covalent Organic Frameworks ◽

2D And 3D ◽

Advanced Applications

Covalent organic frameworks offer a molecular platform for integrating organic units into periodically ordered yet extended 2D and 3D polymers to create topologically well-defined polygonal lattices and built-in discrete micropores and/or mesopores.

Download Full-text