Symmetry determined medium range order (MRO) contributions to the first sharp diffraction peak (FSDP) in non-crystalline oxide and chalcogenide glasses

2009 ◽  
Vol 246 (8) ◽  
pp. 1806-1812 ◽  
Author(s):  
Gerald Lucovsky ◽  
James C. Phillips
1992 ◽  
Vol 150 (1-3) ◽  
pp. 371-375 ◽  
Author(s):  
P. Armand ◽  
A. Ibanez ◽  
E. Philippot ◽  
Q. Ma ◽  
D. Raoux

1994 ◽  
Vol 373 ◽  
Author(s):  
L.C. Qin ◽  
L.W. Hobbs

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.


2021 ◽  
Vol 7 (28) ◽  
pp. eabh1761
Author(s):  
Qi Zhou ◽  
Ying Shi ◽  
Binghui Deng ◽  
Jörg Neuefeind ◽  
Mathieu Bauchy

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.


2010 ◽  
Vol 65 (1-2) ◽  
pp. 123-131 ◽  
Author(s):  
Oleksandr S. Roik ◽  
Oleksiy Samsonnikov ◽  
Volodymyr Kazimirov ◽  
Volodymyr Sokolskii

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.


1998 ◽  
Vol 540 ◽  
Author(s):  
J. M. Gibson ◽  
J-Y. Cheng ◽  
P. Voyles ◽  
M.M.J. TREACY ◽  
D.C. Jacobson

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.


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