Year: 2026
Type: article
Abstract: Containerless processing was used to access and study supercooled liquids and glasses that cannot be made using conventional melting approaches.In-situ measurements of melt atomic structure and density provided insight into how the glass forms.Experiments included making measurements in microgravity where buoyancy driven convection and sedimentation are suppressed.Here we examine the structure and properties of rare earth-aluminate composition liquids and some glasses made from them.The structures show a fundamentally different network behavior from the classical Zachariasen model.The network comprises four and about 40 % five coordinated aluminum ions that share corners or edges and often form triply bonded species with an oxygen ion.The concept of K n is used to evaluate the glass forming behavior in terms of network connectivity and bonding.The temperature dependence of density of the liquid is reported and discussed in the context of processing molten materials in reduced gravity where bubbles can be trapped in the liquid due to lack of buoyancy.The interior structure in samples was investigated using X-ray tomography to investigate how bubbles can cluster inside a liquid drop.
Language: English
Subfield: Ceramics and Composites
Field: Materials Science
Domain: Physical Sciences
Open Access status: diamond
Awards: G102163711, G107546177, G1313983767, G1664757510, G2287611682, G262962599, G3075337988, G3830162158, Ytterbium Bonding in Aluminate Melts and Glasses, G498139845, EXTREME TEMPERATURE SAMPLE ENVIRONMENT FOR MATERIALS RESEARCH USING NEUTRON SCATTERING, THE PROPOSED RESEARCH WILL IMPLEMENT MICROGRAVITY BASED EXPERIMENTS USING THE JAXA FLIGHT ELECTROSTATIC LEVITATION FURNACE (ELF) TO ACHIEVE PRECISE MEASUREMENTS OF THE THERMOPHYSICAL PROPERTIES OF SUPERCOOLED (ALSO CALLED UNDERCOOLED) MOLTEN METAL OXIDES. THE WORK WILL INCLUDE BOTH GROUND BASED AND FLIGHT EXPERIMENTS ON LIQUIDS FORMED FROM ALUMINUM CALCIUM SILICON AND RARE EARTH ELEMENT OXIDE MIXTURES. THESE LIQUIDS ARE PRECURSORS TO HIGH VALUE-ADDED GLASS MATERIALS THAT ARE USED IN PHOTONICS LASERS OPTICAL COMMUNICATIONS AND IMAGING APPLICATIONS. THE OUTCOME OF THE PROPOSED INTERNATIONAL RESEARCH COLLABORATION WILL BE TO: (I) MEASURE TECHNOLOGICALLY IMPORTANT THERMOPHYSICAL PROPERTIES OF NORMAL AND SUPERCOOLED LIQUID METAL OXIDES OF INTEREST IN CONNECTION WITH PRODUCTION OF PHOTONIC AND OPTICAL DEVICE MATERIALS (II) DEVELOP THERMOPHYSICAL PROPERTY DATASETS THAT COMPLEMENT EXISTING ATOMIC STRUCTURE DATA ON THE MATERIALS UNDER INVESTIGATION. USE THE RESULTING DATA TO INCREASE UNDERSTANDING OF THE NATURE OF FRAGILE LIQUIDS AND THE GLASS TRANSITION AND (III) DISSEMINATE THE NEW DATA VIA PUBLICATION THROUGH NASA S PHYSICAL SCIENCES INFORMATICS SYSTEM AND THE MATERIALS GENOME INITIATIVE TO HELP ACCELERATE THE DEVELOPMENT OF NEW PRODUCTS. WE WILL INVESTIGATE THE BEHAVIOR OF LIQUID PHASE METAL OXIDES AS THEY TRANSFORM TO GLASS IN QUIESCENT DIFFUSION-CONTROLLED (I.E. WITHOUT FLUID MOTION) CONDITIONS. THIS WORK IS NEEDED TO OPTIMIZE PHOTONIC AND OPTICAL DEVICE MATERIALS TO OBTAIN UNIFORM PROPERTIES AND STABLE PERFORMANCE IN APPLICATIONS. OVERALL THE WORK WILL ADVANCE THE BROADER GOALS OF OPTIMIZING COMPUTATIONAL MODELING OF MATERIALS PROCESSES AND DEVELOPING SUPERIOR MATERIALS BY DESIGN. THE FLIGHT ELF CAN ACHIEVE PRISTINE MOLTEN AND SUPERCOOLED SAMPLES. SUCH SAMPLES CAN BE STUDIED USING NON-CONTACT MEASUREMENTS OF TEMPERATURE VOLUME SURFACE TENSION AND VISCOSITY. SPHERICAL SAMPLES CA. 2 MM IN DIAMETER SUITABLE FOR EXPERIMENTS IN THE FLIGHT ELF WILL BE MADE BY LASER HEARTH MELTING. PRIOR GROUND-BASED WORK DEMONSTRATED THAT THE SAMPLE MATERIALS CAN BE: (I) LEVITATED USING ELECTROSTATIC METHODS (II) HEATED USING LASER BEAMS AND (III) MELTED WITHOUT SIGNIFICANT EVAPORATION. PROPOSED GROUNDBASED WORK WILL PUSH THE LIMITS OF THESE MEASUREMENTS AND HELP TO OPTIMIZE THE METHODS FOR ANALYSIS FOR THE FLIGHT DATA., G6848031779, G6918803902, G969889393, G993149817
OpenAlex ID: W7140237486