Medium-Range Order in Metamict Silicas

1994 ◽  
Vol 373 ◽  
Author(s):  
L.C. Qin ◽  
L.W. Hobbs
Keyword(s):  
Vitreous Silica ◽  
Anomalous Behavior ◽  
Diffraction Peak ◽  
Range Order ◽  
Medium Range Order ◽  
Medium Range ◽  
Ion Implanted

AbstractThe first sharp diffraction peak from various forms of aperiodic silica was studied. Materials examined include vitreous silica, electron-metamict quartz, neutron-metamict quartz, and Si+ ion-implanted quartz. The peak is attributed to the dominant structural rings existing in the materials, or modification thereof. The anomalous behavior of this peak is also discussed.

The Structure of Ion-Implanted Amorphous Silicon

1998 ◽  
Vol 540 ◽  
Author(s):  
J. M. Gibson ◽  
J-Y. Cheng ◽  
P. Voyles ◽  
M.M.J. TREACY ◽  
D.C. Jacobson
Keyword(s):  
Amorphous Silicon ◽  
Network Model ◽  
Random Network ◽  
Amorphous Semiconductors ◽  
Range Order ◽  
Medium Range Order ◽  
Medium Range ◽  
Large Heat ◽  
Continuous Random Network ◽  
Ion Implanted

AbstractUsing fluctuation microscopy, we show that ion-implanted amorphous silicon has more medium-range order than is expected from the continuous random network model. From our previous work on evaporated and sputtered amorphous silicon, we conclude that the structure is paracrystalline, i.e. it possesses crystalline-like order which decays with distance from any point. The observation might pose an explanation for the large heat of relaxation that is evolved by ion-implanted amorphous semiconductors.

Observations of structural order in ion-implanted amorphous silicon

2001 ◽  
Vol 16 (11) ◽  
pp. 3030-3033 ◽  
Author(s):  
Ju-Yin Cheng ◽  
J. M. Gibson ◽  
D. C. Jacobson
Keyword(s):  
Electron Microscopy ◽  
Amorphous Silicon ◽  
Random Network ◽  
Dark Field ◽  
Range Order ◽  
Length Scale ◽  
Medium Range Order ◽  
Medium Range ◽  
Fluctuation Electron Microscopy ◽  
Ion Implanted

Medium-range order in ion-implanted amorphous silicon has been observed using fluctuation electron microscopy. In fluctuation electron microscopy, variance of dark-field image intensity contains the information of high-order atomic correlations, primarily in medium-range order length scale (1–3 nm). Thermal annealing greatly reduces the order and leaves a random network. It appears that the free energy change previously observed on relaxation may therefore be associated with randomization of the network. In this paper, we discuss the origin of the medium-range order during implantation, which can be interpreted as a paracrystalline state, that is, a disordered network enclosing compacts of highly topologically ordered grains on the length scale of 1–3 nm with significant strain fields.

Low-frequency dynamics and medium-range order in vitreous silica

1996 ◽  
Vol 53 (5) ◽  
pp. 2411-2418 ◽  
Author(s):  
F. Terki ◽  
C. Levelut ◽  
M. Boissier ◽  
J. Pelous
Keyword(s):  
Low Frequency ◽  
Vitreous Silica ◽  
Range Order ◽  
Medium Range Order ◽  
Medium Range

scholarly journals Experimental method to quantify the ring size distribution in silicate glasses and simulation validation thereof

2021 ◽  
Vol 7 (28) ◽  
pp. eabh1761
Author(s):  
Qi Zhou ◽  
Ying Shi ◽  
Binghui Deng ◽  
Jörg Neuefeind ◽  
Mathieu Bauchy
Keyword(s):  
Neutron Diffraction ◽  
Size Distribution ◽  
Diffraction Peak ◽  
Range Order ◽  
Silicate Glasses ◽  
Ring Size ◽  
Medium Range Order ◽  
Simulation Validation ◽  
Medium Range ◽  
Diffraction Patterns

Silicate glasses have no long-range order and exhibit a short-range order that is often fairly similar to that of their crystalline counterparts. Hence, the out-of-equilibrium nature of glasses is largely encoded in their medium-range order. However, the ring size distribution—the key feature of silicate glasses’ medium-range structure—remains invisible to conventional experiments and, hence, is largely unknown. Here, by combining neutron diffraction experiments and force-enhanced atomic refinement simulations for two archetypical silicate glasses, we show that rings of different sizes exhibit a distinct contribution to the first sharp diffraction peak in the structure factor. On the basis of these results, we demonstrate that the ring size distribution of silicate glasses can be determined solely from neutron diffraction patterns, by analyzing the shape of the first sharp diffraction peak. This method makes it possible to uncover the nature of silicate glasses’ medium-range order.

scholarly journals Short and Medium-Range Order in Liquid Ternary Al80Co10Ni10, Al72.5Co14.5Ni13, and Al65Co17.5Ni17.5 Alloys

2010 ◽  
Vol 65 (1-2) ◽  
pp. 123-131 ◽  
Author(s):  
Oleksandr S. Roik ◽  
Oleksiy Samsonnikov ◽  
Volodymyr Kazimirov ◽  
Volodymyr Sokolskii
Keyword(s):  
Three Dimensional ◽  
Range Order ◽  
Ternary Alloys ◽  
X Ray Diffraction ◽  
Medium Range Order ◽  
Intermediate Range Order ◽  
Transition Metal Atoms ◽  
Medium Range ◽  
Three Dimensional Models ◽  
Co Alloys

AbstractA local short-to-intermediate range order of liquid Al80Co10Ni10, Al72.5Co14.5Ni13, and Al65Co17.5Ni17.5 alloys was examined by X-ray diffraction and the reverse Monte Carlo modelling. The comprehensive analysis of three-dimensional models of the liquid ternary alloys was performed by means of the Voronoi-Delaunay method. The existence of a prepeak on the S(Q) function of the liquid alloys is caused by medium range ordering of 3d-transition metal atoms in dense-packed polytetrahedral clusters at temperatures close to the liquidus. The non-crystalline clusters, represented by aggregates of pentagons that consist of good tetrahedra, and chemical short-range order lead to the formation of the medium range order in the liquid binary Al-Ni, Al-Co and ternary Al-Ni-Co alloys.

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