scholarly journals Wide Range Solid Solutions with Composite Modulated Structures

2014 ◽  
Vol 70 (a1) ◽  
pp. C168-C168
Author(s):  
Siegbert Schmid
Keyword(s):  
Solid Solutions ◽  
Organic Conductors ◽  
High Tc Superconductors ◽  
High Tc ◽  
X Ray ◽  
Transmission Electron ◽  
Modulated Structures ◽  
Lattice Periodicity ◽  
Wide Range ◽  
Structural Aspects

Systems that form modulated structures are a fascinating class of materials, which lack lattice periodicity but may still be perfectly long-range ordered [1]. Such systems exist across the whole range of chemical disciplines from organic conductors to high-Tc superconductors and minerals. The importance of modulated structures has been recognised, but there have been few systematic studies across composition ranges of wide-range solid solutions that form composite modulated structures. Such a systematic investigations further our understanding of crystal chemical and structural aspects of modulated structures as well as the reasons for their existence. Examples for such wide-range solid solutions will be presented, with structures investigated using X-ray and neutron powder diffraction as well as transmission electron microscopy.

Structure, Composition and Superconductivity of High Tc Tl–Ba–Ca–Cu–O System

1989 ◽  
Vol 156 ◽  
Author(s):  
Yasuhiko Syono ◽  
Masae Kikuchi ◽  
Satoru Nakajima ◽  
Teruo Suzuki ◽  
Takeo Oku ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Electron Probe ◽  
Magnetic Measurements ◽  
Chemical Compositions ◽  
Superconducting Properties ◽  
High Tc Superconductors ◽  
Critical Temperatures ◽  
High Tc ◽  
X Ray ◽  
Transmission Electron

ABSTRACTBulk high Tc superconductors of Tl2Ba2Can−1CunO2n+4 (n=1−4) and TlBa2Can−1CunO2n+3 (n=2−5) were synthesized, and their structures, chemical compositions and superconducting properties were studied by means of X-ray powder diffraction, electron probe microanalysis, transmission electron microscopy, and electrical and magnetic measurements. Superconducting critical temperatures are discussed in terms of average Cu valence and Cu-O bond length within the plane which vary with the number of Cu layers.

scholarly journals Synthesis of Ce1−xPdxO2−δ Solid Solution in Molten Nitrate

Catalysts ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 640
Author(s):  
Hideaki Sasaki ◽  
Keisuke Sakamoto ◽  
Masami Mori ◽  
Tatsuaki Sakamoto
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Solid Solutions ◽  
Photoelectron Spectroscopy ◽  
Synthesis Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Co Precipitation ◽  
Ionic States

CeO2-based solid solutions in which Pd partially substitutes for Ce attract considerable attention, owing to their high catalytic performances. In this study, the solid solution (Ce1−xPdxO2−δ) with a high Pd content (x ~ 0.2) was synthesized through co-precipitation under oxidative conditions using molten nitrate, and its structure and thermal decomposition were examined. The characteristics of the solid solution, such as the change in a lattice constant, inhibition of sintering, and ionic states, were examined using X-ray diffraction (XRD), scanning electron microscopy–energy-dispersive X-ray spectroscopy (SEM−EDS), transmission electron microscopy (TEM)−EDS, and X-ray photoelectron spectroscopy (XPS). The synthesis method proposed in this study appears suitable for the easy preparation of CeO2 solid solutions with a high Pd content.

Studies of Microstructures in High-Tc Superconductors by X-ray Absorption Techniques

1990 ◽  
pp. 281-284
Author(s):  
A. Krol ◽  
C. J. Sher ◽  
Z. H. Ming ◽  
C. S. Lin ◽  
L. W. Song ◽  
...  
Keyword(s):  
High Tc Superconductors ◽  
High Tc ◽  
X Ray ◽  
X Ray Absorption

X-ray emission spectra of vanadium atoms in a new series of (Cu,V)-based high-Tc superconductors

2003 ◽  
Vol 170 (1) ◽  
pp. 188-191 ◽  
Author(s):  
E.Z. Kurmaev ◽  
A. Moewes ◽  
G.T. Woods ◽  
T.A. Callcott ◽  
N.D. Zhigadlo ◽  
...  
Keyword(s):  
Emission Spectra ◽  
High Tc Superconductors ◽  
High Tc ◽  
X Ray

Structural aspects of the hisingerite-neotocite series

Clay Minerals ◽  
1983 ◽  
Vol 18 (1) ◽  
pp. 21-31 ◽  
Author(s):  
R. A. Eggleton ◽  
J. H. Pennington ◽  
R. S. Freeman ◽  
I. M. Threadgold
Keyword(s):  
Function Analysis ◽  
Pore Space ◽  
Hollow Spheres ◽  
X Ray ◽  
Broken Hill ◽  
Transmission Electron ◽  
X Ray Absorption ◽  
Interconnected Pore ◽  
Intermediate Member ◽  
Structural Aspects

AbstractTransmission electron microscopy, X-ray radial distribution function analysis, chemical analysis, X-ray absorption edge spectroscopy, and Mössbauer spectroscopy combine to confirm an amorphous or gel structure for minerals of the hisingerite-neotocite series: (Fe,Mn)0.8SiO3.1.2H2O. A framework of (Fe,Mn)O6 octahedra and [SiO4] tetrahedra form hollow spheres, 50–100 Å in diameter, cross-bonded into a physically isotropic solid with as much as 10% interconnected pore space. The outer 10–20 Å of the spheres has a rudimentary structure, possibly marking the onset of segregation into Si-rich and (Fe,Mn)-rich layers. The Broken Hill mineral ‘sturtite’ is an intermediate member of the hisingerite-neotocite series.

A Study of Grain Boundaries in High TC Superconducting Yba2Cu3O7-x Thin Films Using High Resolution Analytical Stem

1989 ◽  
Vol 169 ◽  
Author(s):  
D. H. Shin ◽  
J. Silcox ◽  
S. E. Russek ◽  
D. K. Lathrop ◽  
R. A. Buhrman
Keyword(s):  
Thin Films ◽  
High Resolution ◽  
Grain Boundaries ◽  
Scanning Transmission Electron Microscope ◽  
Atomic Resolution ◽  
High Tc ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Edx Microanalysis

AbstractGrain boundaries in thin films of high Tc YBa2Cu3O7-x superconductors have been investigated with high resolution scanning transmission electron microscope (STEM) imaging and nanoprobe energy dispersive x-ray (EDX) analysis. Atomic resolution images indicate that the grain boundaries are mostly clean, i.e., free of a boundary layer of different phase or of segregation, and are often coherent. EDX microanalysis with a 10 Å spatial resolution also indicates no composition deviation at the grain boundaries.

Electron Microscopy Study of Stoichiometric and Non-Stoichiometric Titania

1997 ◽  
Vol 3 (S2) ◽  
pp. 669-670
Author(s):  
Solórzano I.G. ◽  
Kotani T. ◽  
Tuller H.L. ◽  
Van der Sande J.B.
Keyword(s):  
Electron Microscopy ◽  
Electric Activity ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Boundary Structure ◽  
High Tc Superconductors ◽  
High Tc ◽  
Grain Boundary Structure ◽  
Transmission Electron ◽  
Crystallographic Shear

It is currently well recognized that oxides are able to accommodate deviations from stoichiometry (1) and great advances in this understanding have been achieved by using transmission electron microscopy (TEM), particularly through lattice imaging and electron diffraction techniques (2). The physical properties of non-stoichiometric oxides are strongly influenced by their exact composition and for this reason they represent a class of materials with increasing and novel properties that are put to use in, for example, oxygen sensors and high-Tc superconductors. On the other hand, in electroceramic materials, such as TiO2, grain boundary structure and chemistry are important to be characterized in detail since these variables are responsible for the electric activity.Rutile (TiO2) can accommodate relatively large deviations from stoichiometry (TiOx with 2.0≥x≤ 1.75) by the crystallographic shear (CS) mechanism (1). The formation of CS planes is effectively a two-step process which involves the ordering of oxygen vacancies on a crystallographic plane and on their elimination by a shear of the lattice.

scholarly journals Facile Fabrication of CeO2/Electrochemically Reduced Graphene Oxide Nanocomposites for Vanillin Detection in Commercial Food Products

Nanomaterials ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1356 ◽  
Author(s):  
Xue Nie ◽  
Rui Zhang ◽  
Zheng Tang ◽  
Haiyan Wang ◽  
Peihong Deng ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Linear Sweep Voltammetry ◽  
X Ray ◽  
Transmission Electron ◽  
Reduced Graphene ◽  
Electrochemically Reduced Graphene Oxide ◽  
Wide Range ◽  
Facile Fabrication

In this paper, CeO2 nanoparticles were synthesized by the solvothermal method and dispersed uniformly in graphene oxide (GO) aqueous solution by ultrasonication. The homogeneous CeO2-GO dispersion was coated on the surface of a glassy carbon electrode (GCE), and the CeO2/electrochemically reduced graphene oxide modified electrode (CeO2/ERGO/GCE) was obtained by potentiostatic reduction. The results of X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) showed that CeO2 nanocrystals were uniformly coated by gossamer like ERGO nanosheets. The electrochemical behavior of vanillin on the CeO2/ERGO/GCE was studied by cyclic voltammetry (CV). It was found that the CeO2/ERGO/GCE has high electrocatalytic activity and good electrochemical performance for vanillin oxidation. Using the second derivative linear sweep voltammetry (SDLSV), the CeO2/ERGO/GCE provides a wide range of 0.04–20 µM and 20 µM–100 µM for vanillin detection, and the detection limit is estimated to be 0.01 µM after 120 s accumulation. This method has been successfully applied to the vanillin detection in some commercial foods.

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