Recent advances in identifying the structure of liquid and glassy oxide and chalcogenide materials under extreme conditions: a joint approach using diffraction and atomistic simulation

Abstract

The advent of advanced instrumentation and measurement protocols makes it increasingly feasible to use X-ray and neutron diffraction methods to investigate the structure of liquid and glassy materials under extreme conditions of high-temperatures and/or high-pressures. In particular, a combination of diffraction and modern simulation techniques is allowing for an understanding of the structure of these disordered materials at both the atomistic and electronic levels. In this article, we highlight some of the recent work in solving the structure of liquid and glassy oxide and chalcogenide materials under extreme conditions. We consider, in turn, the use of aerodynamic levitation with laser heating to investigate the structure of high-temperature oxide melts and to fabricate novel glassy materials by container-less processing; the use of high-pressure methods in the gigapascal regime to investigate the mechanisms of network collapse for glassy network structures; and the simultaneous application of highpressures and high-temperatures to explore the structure of disordered materials. Finally, we consider the use of other quantum-beam diffraction-based techniques for probing the order hidden in the correlation functions that describe the structure of disordered matter.

Effect of sintering parameters using the central composite design method, electronic structure and physical properties of yttria-partially stabilized ZrO2 commercial ceramics

“…In these unit cells the zirconium (Zr) atoms are coordinated to seven oxygens forming a heptahedron-type polyhedron with the configuration of distorted deltahedral [ZrO 7 ] clusters and the prescence of 7 vertices (V), 9 faces (F) and 14 edges (E) composed of eight triangular faces and one square face [54][55][56]. These [ZrO 7 ] clusters form irregular polyhedra in the lattice, and for each ZrO 2 ceramics we have verified, at different temperatures and times, that the deltahedral [ZrO 7 ] clusters exhibit a particular characteristics related to the differences in the O-Zr-O bond angles [57,58]. However, in Fig.…”

Vibrational and structural properties of P2O5 glass: Advances from a combined modeling approach

“…However, despite many studies dedicated to v-P 2 O 5 [8,9,[29][30][31][32][33][34], up to now, it was not possible to generate v-P 2 O 5 models with more than 75% of Q 3 units. Recently, Kohara et al developed a hybrid RMC approach which opened the door to confidently treat glass systems, providing new insights into the structural properties [35][36][37]. Owing to these advances, we generate three models with 112 atoms: two RMC models (hereafter labeled RMC1 and RMC2) and one CMD model.…”

“…Owing to these advances, we generate three models with 112 atoms: two RMC models (hereafter labeled RMC1 and RMC2) and one CMD model. RMC modeling is performed using the RMC++ code [35][36][37]. The difference between the RMC1 and RMC2 models lies in the different constraints that were applied in RMC calculations.…”

“…Distributions are presented for RMC1/RMC2 models obtained by Kohara's RMC approach [35,36] and for the CMD model obtained by classical MD [29]. Q n species for the PO 4 structural unit are shown schematically in the inset.…”

Impact of pressure on the structure of glass and its material properties

“…12 Nevertheless, the combination of experiment with modern modelling methods is beginning to reveal the structure and related properties of glassy materials at high pressure. 9,13 In the following, silica glass will be used as an exemplar because it is the basic constituent of silicate materials, and there is much information on its pressure-dependent structure and properties from both experiment and computer simulation. Here, it is important to realise that the force applied in an experiment will not induce pure normal stress, unless a pressure transmitting medium is employed to give hydrostatic conditions.…”