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Ott, Ryan

Publications and source records attributed to Ott, Ryan.

24 records · Page 2
All sourcesNASA NTRSDOE OSTI
DOE OSTI2017

Large-scale production of (GeTe) x (AgSbTe 2 ) 100$-$x (x=75, 80, 85, 90) with enhanced thermoelectric properties via gas-atomization and spark plasma sintering

(GeTe) x (AgSbTe 2 ) 100$-$x : TAGS thermoelectrics are an attractive class of materials due to their combination of non-toxicity and good conversion efficiency at mid-temperature ranges. Here in the present work, we have utilized energy and time efficient high-pressure gas atomization and spark-plasma sintering techniques for large-scale preparation of samples with varying composition (i.e., (GeTe) x (AgSbTe 2 ) 100$-$x where x = 75, 80, 85, and 90). High-temperature x-ray diffraction was used to understand the phase transformation mechanism of the as-atomized powders. Detailed high-resolution transmission electron microscopy of the sintered samples revealed the presence of nanoscale precipitates, antiphase, and twin boundaries. The nanoscale twins and antiphase boundaries serve as phonon scattering centers, leading to the reduction of total thermal conductivity in TAGS-80 and 90 samples. The maximum ZT obtained was 1.56 at 623 K for TAGS-90, which was ~94% improvement compared to values previously reported. The presence of the twin boundaries also resulted in a high fracture toughness (K IC ) of the TAGS-90 sample due to inhibition of dislocation movement at the twin boundary.

36 MATERIALS SCIENCE↗
DOE OSTI2016

Report 1: International Cooperation to Development of Strategy and R&D Collaboration for Substitution of Rare Earth Resources and Report 2: Development of Magnetocaloric Alloys without Critical Elements

A Memorandum of Understanding was signed between the Ames Laboratory and Korea Institute of Industrial Technology (KITECH) in April of 2011 to establish a close cooperative relationship of research on Rare Metals. The Ames Laboratory through its operating contractor, Iowa State University, and the KITECH, as one of the goals of a joint Memorandum of Understanding, made agreement on a Cooperative Research and Development Agreement (CRADA) for a personnel exchange in April of 2012. Ames Laboratory and KITECH would be jointly performing collaboration work in this cooperation as the Parties. The individual backgrounds and capabilities of the Parties are ideally suited to the successful execution of this work. The Ames Laboratory has a history spanning more than 60 years of pioneering work in rare-earth (RE) research. With its team of internationally recognized rare-earth experts, the Ames Laboratory is uniquely positioned to provide the knowledge, expertise and training necessary to help ensure a global leadership position for the United States in rare-earth research, development and applications. The KITECH was founded to promote technological capability of small and medium-sized enterprises in Korea and has a mission of supporting research on materials science and engineering in Korea. In 2009, Korea Institute for Rare Metals (KIRAM) at KITECH was established. KIRAM makes selection and funding decisions for technology projects for strategic rare metals, and provides oversight of R&D programs. The KIRAM is focusing on the commercialization and recycling of particular rare metals. In addition KIRAM will be coordinating government, local universities, and small to medium enterprises to facilitate R&D support for core technologies. KIRAM will be carrying them through to commercialization, and establishing new industry.

36 MATERIALS SCIENCE↗
DOE OSTI2014

Ames Lab 101: 3D Metals Printer

To meet one of the biggest energy challenges of the 21st century - finding alternatives to rare-earth elements and other critical materials - scientists will need new and advanced tools. The Critical Materials Institute at the U.S. Department of Energy's Ames Laboratory has a new one: a 3D printer for metals research. 3D printing technology, which has captured the imagination of both industry and consumers, enables ideas to move quickly from the initial design phase to final form using materials including polymers, ceramics, paper and even food. But the Critical Materials Institute (CMI) will apply the advantages of the 3D printing process in a unique way: for materials discovery.

36 MATERIALS SCIENCE↗
DOE OSTI2012

Ames Lab 101: Rare-Earth Recycling

Recycling keeps paper, plastics, and even jeans out of landfills. Could recycling rare-earth magnets do the same? Perhaps, if the recycling process can be improved. Scientists at the U.S. Department of Energy's Ames Laboratory are working to more effectively remove the neodymium, a rare earth, from the mix of other materials in a magnet.

36 MATERIALS SCIENCE↗