Abstract
Understanding the liquid structure provides information that is crucial to uncovering the nature of the glass-liquid transition. We apply an aerodynamic levitation technique and high-energy X-rays to liquid (l)-Er2O3 to discover its structure. The sample densities are measured by electrostatic levitation at the International Space Station. Liquid Er2O3 displays a very sharp diffraction peak (principal peak). 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-ZrO2. The atomic structure of l-Er2O3 comprises distorted OEr4 tetraclusters in nearly linear arrangements, as manifested by a prominent peak observed at ~180° in the Er–O–Er bond angle distribution. This structural feature gives rise to long periodicity corresponding to the sharp principal peak in the X-ray diffraction data. A persistent homology analysis suggests that l-Er2O3 is homologically similar to the crystalline phase. Moreover, electronic structure calculations show that l-Er2O3 has a modest band gap of 0.6 eV that is significantly reduced from the crystalline phase due to the tetracluster distortions. The estimated viscosity is very low above the melting point for l-ZrO2, and the material can be described as an extremely fragile liquid.
Highlights
Determining the liquid structure is the first step in understanding the nature of glass-liquid transitions
The density functional – molecular dynamics (DF-MD) simulations were performed with a Nóse-Hoover thermostat[33] and a time step of 2 fs, with an initial atomic configuration given by the benchmark RMC model mentioned above with 500 atoms
The density trends increase with increasing cation atomic number, they do not show a clear relation
Summary
The density of liquid (l-) Er2O3 was measured with an ELF at the ISS. A sample of 2 mm in diameter was prepared by melting Er2O3 powder with a purity of 99.99% and solidifying it in an aerodynamic levitator. The cell volume was determined from the number densities of l-Er2O3 at the melting point, which were calculated with the density measured by the ISS-ELF. The PBE functional[28] was used for the geometry optimization and the molecular dynamics simulations, whereas the HSE06 hybrid functional[29] was used to obtain the electronic densities of states (DOSs) and their projections to produce more realistic electronic band gaps and test the effect of the 4f electrons in c-Er2O3. The density functional – molecular dynamics (DF-MD) simulations were performed with a Nóse-Hoover thermostat[33] and a time step of 2 fs, with an initial atomic configuration given by the benchmark RMC model mentioned above with 500 atoms. The persistence diagrams were calculated using the HomCloud package[35]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
