The Structural Diversity of the Nanoworld

Shevchenko, V. Ya.; Madison, A. E.; Shudegov, V. E.

doi:10.1023/b:gpac.0000007934.93203.f3

Cited by 26 publications

(23 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is clear that only the manifold concept can underlie the mathematical formalism for describing nanostructures and is completely consistent with the concepts of fragmentariness, structural inhomogeneity [1,2], and local curvature [14,17] and the principle of assembling a complex structure from simple building blocks [15]. In the general case, an individual structural complex corresponds to a local coordinate neighborhood U i of the bundle base and the complete closed set of geometrical structural complexes is determined by the fiber (structural group) of the relevant fiber bundle.…”

Section: The Local Approach and Nanostructures With Coherent Boundariesmentioning

confidence: 80%

“…

In particular, reasoning from the results of neutron diffraction and X-ray diffraction investigations of ZrO 2 nanoparticles, Burkhanov et al [3] proposed a twophase model allowing for the difference between the central and peripheral regions of a particle and their pseudomorphic conjugation.

…”

mentioning

confidence: 99%

“…In our recent works [1,2], we analyzed the structural diversity of nanoparticles and the fragmentariness of their structure and formulated the statement that the structural inhomogeneity is a fundamental property of the nanostate. This statement was experimentally confirmed for a number of materials.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Nanostructures with coherent boundaries and the local approach

et al. 2004

Self Cite

View full text Add to dashboard Cite

In our recent works [1,2], we analyzed the structural diversity of nanoparticles and the fragmentariness of their structure and formulated the statement that the structural inhomogeneity is a fundamental property of the nanostate. This statement was experimentally confirmed for a number of materials.In particular, reasoning from the results of neutron diffraction and X-ray diffraction investigations of ZrO 2 nanoparticles, Burkhanov et al. [3] proposed a twophase model allowing for the difference between the central and peripheral regions of a particle and their pseudomorphic conjugation. Palosz et al. [4] also used a two-phase model to interpret their diffraction data for SiC, GaN, and diamond nanoparticles. The concept of an "apparent lattice parameter" clearly indicates strong deviations of the position of Bragg peaks (especially at small angles) from the predicted crystallographic positions. The inference was made that a unique lattice parameter for microcrystallites cannot be determined by standard powder diffractometry. The behavior of nanocrystalline powders under pressure cannot be satisfactorily explained in terms of a unique compressibility coefficient. This also counts in favor of the twophase structure of nanoparticles.Earlier [5][6][7], structurally inhomogeneous zirconia nanoparticles that consist of interpenetrating fragments with different symmetries and are characterized by the orientational relationships "incompatible" from the standpoint of classical crystallography were experimentally found for the first time. Regularly oriented fragments with different symmetries, for which the requirements of classical crystallography are not satisfied (the interface need not be a plane, so that the orientational relationships do not necessarily correspond to the Miller indices and the fragments themselves need not be crystals), were referred to as centaurs [5]. The boundaries of fragments are coherent, and, therefore, these particles can be defined as nanostructures with coherent boundaries.Alok Singh and Tsai [8] revealed that the cubic and icosahedral phases in metal alloys can intergrow in a regular oriented manner. It was found that the threefold axes of the cubic phase coincide in direction with the twofold axes of the icosahedral phase and the cubic twofold axes are almost parallel to the icosahedral fivefold axes. The interface is not a plane, and the orientational relationships do not correspond to rational ratios of the corresponding Miller indices and are inconsistent with the assumption that this cubic phase is a quasicrystalline approximant of the icosahedral phase.The structural inhomogeneity of nanoparticles has become evident owing to widespread use of high-resolution electron microscopy [7,9]. Of special interest are materials prepared by ultrafast solidification, because extreme conditions often lead to the formation of vitreous or unstable crystalline structures and quasicrystals. Specifically, it has been demonstrated that fragments of cubic crystals can intergrow to form a hierarchic st...

show abstract

Section: The Local Approach and Nanostructures With Coherent Boundariesmentioning

confidence: 80%

“…

…”

mentioning

confidence: 99%

See 1 more Smart Citation

Nanostructures with coherent boundaries and the local approach

et al. 2004

Self Cite

View full text Add to dashboard Cite

show abstract

“…In such a case only Na + and K + ions participate in the chemical process. Ions are on the glass surface in no equilibrium state and their activation energy of leaching is 7 times (for K + ) and 13 times (for Na + ) less compared with activation energy of these ions diffusion in glass volume [17].…”

Section: Resultsmentioning

confidence: 99%

Prospective of Glass Powder as Active Additive to Portland Cement

Шевченко¹,

Kotsay²

2015

ChChT

View full text Add to dashboard Cite

show abstract

“…In the recent years, on the basis of the ideas developed above, the Saint Petersburg group at ISC RAS in cooperation with A. Mackay has succeeded in obtaining results, the most important of which are the following [5][6][7][8][9][10][11][12][13][14].…”

Section: Prd Structurementioning

confidence: 99%

Geometrical principles of the self-assembly of nanoparticles

Shevchenko

Mackay

2008

Glass Phys Chem

Self Cite

View full text Add to dashboard Cite

Nanoworld is the part of Space in which, from atoms, by self-assembly formed substance, living or nonliving.Among the 25 key scientific problems for chemists of the 21st century, published in the journal "Science," there was a question: "How far can we push chemical self-assembly?" What then are the main features of self-assembly?Two traditional rules are known: (1) like goes with like and (2) self-assembly is controlled by energyfavorable reactions and local order.The process of the self-assembly of complex systems underlies nanostructure technology, because, at the size level of 30-50 nm, planned extrinsic assembly (microfabrication, electron-beam etching, etc.) is too complex and expensive and thus, for mass production, we must rely on self-assembly from the outset to obtain macroscopic structures "top-down" or "bottom-up."Ideas about the formation of complex structures by the self-assembly of individual components through their local interactions, rather than by the influence of external factors, underlie the principles of "cellular automata." Mathematical cellular automata provide a powerful analogy ready to be materialized.We must note that, during the natural synthesis of biological objects, DNA codes include error correction, and, therefore, in order to design the self-assembly of

show abstract

The Structural Diversity of the Nanoworld

Cited by 26 publications

References 10 publications

Nanostructures with coherent boundaries and the local approach

Nanostructures with coherent boundaries and the local approach

Prospective of Glass Powder as Active Additive to Portland Cement

Geometrical principles of the self-assembly of nanoparticles

Contact Info

Product

Resources

About