Comparing RMC and RDM glass structure modelling methods
نویسنده
چکیده
The Reverse Monte Carlo (RMC) method involves usually one or several thousands atoms, and modelling may start from random atomic positions. The Rietveld for disordered material (RDM) method needs a crystal structure as starting mean model, with hardly more than 20 independent atoms. The two methods are reconciled when a satisfying RDM model, enlarged by multiplying the cell axes, is subjected to random moves by the RMC method. Three examples are presented : glassy SiO2, ZnCl2 and NaPbM2F9 (M = Fe, V). In all cases, coordination were constrained (SiO4 and ZnCl4 tetrahedra ; MF6 octahedra), so that the final RMC models keep essentially the crystal structure features of the RDM starting models which were phases in which devitrify the glasses.
منابع مشابه
Reverse Monte Carlo modelling
Reverse Monte Carlo (RMC) modelling is a general method of structural modelling based on experimental data. RMC modelling can be applied to many different sorts of data, simultaneously if wished. Powder and single-crystal neutron diffraction (including isotopic substitution), x-ray diffraction (including anomalous scattering) and electron diffraction, extended x-ray absorption fine structure an...
متن کاملNetwork structure of Mo-oxide glasses
The structure of molybdate glasses have been investigated by neutron and highenergy X-ray diffraction coupled with Reverse Monte Carlo (RMC) simulation technique. From the modelling the partial atomic correlation functions gij(r), the coordination number distributions CNij and bond angle distributions have been revealed. For binary 90MoO310Nd2O3 glass composition the fraction of MoO4/MoO6 was 0...
متن کاملAtomic structure of Mg-based metallic glass investigated with neutron diffraction, reverse Monte Carlo modeling and electron microscopy
The structure of a multicomponent metallic glass, Mg65Cu20Y10Ni5, was investigated by the combined methods of neutron diffraction (ND), reverse Monte Carlo modeling (RMC) and high-resolution transmission electron microscopy (HRTEM). The RMC method, based on the results of ND measurements, was used to develop a realistic structure model of a quaternary alloy in a glassy state. The calculated mod...
متن کاملAtomic order and cluster energetics of a 17 wt% Si-based glass versus the liquid phase.
Aerodynamic levitation of a multicomponent 17 wt% Si glass formed by rapid quenching of the melt phase was studied by high resolution x-ray diffraction (XRD) and reverse Monte Carlo (RMC) modelling. The main local atomic order features comprised interactions between Si, Fe and Mg polyhedra, the stereochemistry of which was on a par with the literature. Both the glass and the liquid state appear...
متن کاملThe effect of aerobic exercise along with resveratrol supplementation on AMPK and MAFbx gene expression of myocardial diabetic rats
Background and Aim: Diabetes is a metabolic disease that is associated with heart injury. It has been shown that exercise training and resveratrol can improve the cardiac structure and function of diabetic subjects. The aim of the present study was to examine the effect of aerobic training along with resveratrol on gene expression of AMPK and MAFbx on cardiac tissue of diabetic experimental mod...
متن کامل