Combined computational and experimental investigation of high temperature thermodynamics and structure of cubic ZrO2 and HfO2
Year: 2018
Type: article
Abstract: Structure and thermodynamics of pure cubic ZrO2 and HfO2 were studied computationally and experimentally from their tetragonal to cubic transition temperatures (2311 and 2530 °C) to their melting points (2710 and 2800 °C). Computations were performed using automated ab initio molecular dynamics techniques. High temperature synchrotron X-ray diffraction on laser heated aerodynamically levitated samples provided experimental data on volume change during tetragonal-to-cubic phase transformation (0.55 ± 0.09% for ZrO2 and 0.87 ± 0.08% for HfO2), density and thermal expansion. Fusion enthalpies were measured using drop and catch calorimetry on laser heated levitated samples as 55 ± 7 kJ/mol for ZrO2 and 61 ± 10 kJ/mol for HfO2, compared with 54 ± 2 and 52 ± 2 kJ/mol from computation. Volumetric thermal expansion for cubic ZrO2 and HfO2 are similar and reach (4 ± 1)·10−5/K from experiment and (5 ± 1)·10−5/K from computation. An agreement with experiment renders confidence in values obtained exclusively from computation: namely heat capacity of cubic HfO2 and ZrO2, volume change on melting, and thermal expansion of the liquid to 3127 °C. Computed oxygen diffusion coefficients indicate that above 2400 °C pure ZrO2 is an excellent oxygen conductor, perhaps even better than YSZ.
Source: Scientific Reports
Language: English
Subfield: Ceramics and Composites
Field: Materials Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,690
Awards: Collaborative Research: Experimental and Computational Study of Structure and Thermodynamics of Rare Earth Oxides above 2000 C, G3075337988, G3226045097, XSEDE 2.0: Integrating, Enabling and Enhancing National Cyberinfrastructure with Expanding Community Involvement, G3812616897, G4382344593, G4636388355, G4881568376, G514696732, G5459207137, G6806689448, G6848031779, G6918803902, G8423653713, Collaborative research: experimental and computational study of structure and thermodynamics of rare earth oxides above 2000 C, G874299497, SusChEM: Collaborative Research: experimental and computational study of structure and thermodynamics of rare earth oxides above 2000 C, SusChEM: Collaborative Research: experimental and computational study of structure and thermodynamics of rare earth oxides above 2000 C
OpenAlex ID: W2895292548