Many experimental and theoretical structural studies of liquids and glasses have been performed, and with the advent of advanced synchrotron and neutron sources and the development of high-performance computers, they have led to great progress in our understanding of liquid and glass structures 4, 5. In contrast, typical fragile liquids are chalcogenides and iron phosphates, the networks of which are mostly ionic and the viscosities of which deviate significantly from the Arrhenius behavior. Their networks are covalently bonded, and the viscosities show an Arrhenius temperature dependence. Typical strong liquids are SiO 2, GeO 2, and B 2O 3. He interpreted the strong and fragile behavior of liquids in terms of topological differences in potential energy hypersurfaces of the configuration space. Furthermore, Angell 3 introduced the concept of “fragility” in glass-forming liquids (GFLs). Zachariasen 1 and Sun 2 proposed the basic concepts of glass formation by classifying constituents into glass formers, glass modifiers, and intermediates. Since glasses play an important role in technology, glass formation has been studied extensively. Moreover, high-quality measurements are difficult to obtain at high temperatures. However, a diffraction measurement of liquid provides very limited structural information because the liquid structure lacks long-range periodicity, and a Fourier transform of the diffraction data provides only pairwise correlations. The estimated viscosity is very low above the melting point for l-ZrO 2, and the material can be described as an extremely fragile liquid.ĭetermining the liquid structure is the first step in understanding the nature of glass-liquid transitions. Moreover, electronic structure calculations show that l-Er 2O 3 has a modest band gap of 0.6 eV that is significantly reduced from the crystalline phase due to the tetracluster distortions. A persistent homology analysis suggests that l-Er 2O 3 is homologically similar to the crystalline phase. This structural feature gives rise to long periodicity corresponding to the sharp principal peak in the X-ray diffraction data. The atomic structure of l-Er 2O 3 comprises distorted OEr 4 tetraclusters in nearly linear arrangements, as manifested by a prominent peak observed at ~180° in the Er–O–Er bond angle distribution. Applying a combined reverse Monte Carlo – molecular dynamics approach, the simulations produce an Er–O coordination number of 6.1, which is comparable to that of another nonglass-forming liquid, l-ZrO 2.
Liquid Er 2O 3 displays a very sharp diffraction peak (principal peak). The sample densities are measured by electrostatic levitation at the International Space Station. We apply an aerodynamic levitation technique and high-energy X-rays to liquid ( l)-Er 2O 3 to discover its structure. Understanding the liquid structure provides information that is crucial to uncovering the nature of the glass-liquid transition.
0 kommentar(er)
