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Understanding correlation between thermodynamics and mechanical behavior
Because nanocrystalline materials have their properties strongly dependent on the interfacial features, in this project we design low energy grain boundaries to improve mechanical behavior. In particular we are looking at oxide nanoceramics. This project is in its initial stages and the concept is slowly being developed.
Some related publications:
    Colossal Grain Boundary Strengthening in Ultrafine Nanocrystalline Oxides By: Muche, N.F.; Drazin, J.; Mardinly, J.; Dey, S.; MATERIALS LETTERS; 2016
    Thermodynamic Strengthening of Heterointerfaces in Nanoceramics By: Wu, Longjia; Dey, Sanchita; Mardinly, John; et al. CHEMISTRY OF MATERIALS Volume: 28 Issue: 9 Pages: 2897-2901 Published: MAY 10 2016
Ceramic materials often exhibit novel physical and chemical properties as their sizes approach nanometer dimensions.
These new properties have inspired a variety of new applications in several fields, ranging from nanosensors to cathode materials for fuel cells and lithium batteries. As well, the possibility is opened for the development of new materials in response to the current energy problems such as the U.S. increasing demand for energy, dependence on foreign oils, and climate change. However, the optimization of nanoceramic processing is still a challenge, and understanding the fundamental concepts requires further research. Within this project, Prof. Castro focuses on the larger volume fraction of interfaces present in nanoceramics to improve processing control. His groups uses ultra-sensitive calorimetric techniques to quantify interfacial energies and use the data to predict and control properties.
Some related publications:
    Sintering and Nanostability: The Thermodynamic Perspective By: Castro, Ricardo H. R.; Gouvea, Douglas JOURNAL OF THE AMERICAN CERAMIC SOCIETY (INVITED FEATURE ARTICLE) Volume: 99 Issue: 4 Pages: 1105-1121 Published: APR 2016
    On the thermodynamic stability of nanocrystalline ceramics By: Castro, Ricardo H. R. MATERIALS LETTERS Volume: 96 Pages: 45-56 Published: APR 1 2013
    Fast firing of bismuth doped yttria-stabilized zirconia for enhanced densification and ionic conductivity By: Li, Hui; Kon, Alexander; Chang, Chi-Hsiu; et al. JOURNAL OF THE CERAMIC SOCIETY OF JAPAN Volume: 124 Issue: 4 Pages: 370-374 Published: APR 2016
    The Nanocrystalline SnO2-TiO2 SystemPart I: Structural Features By: Miagava, Joice; Rubbens, Annick; Roussel, Pascal; et al. JOURNAL OF THE AMERICAN CERAMIC SOCIETY Volume: 99 Issue: 2 Pages: 631-637 Published: FEB 2016
    The Nanocrystalline SnO2-TiO2 SystemPart II: Surface Energies and Thermodynamic Stability By: Miagava, Joice; da Silva, Andre L.; Navrotsky, Alexandra; et al. JOURNAL OF THE AMERICAN CERAMIC SOCIETY Volume: 99 Issue: 2 Pages: 638-644 Published: FEB 2016
    Grain growth resistant nanocrystalline zirconia by targeting zero grain boundary energies By: Dey, Sanchita; Chang, Chi-Hsiu; Gong, Mingming; et al. JOURNAL OF MATERIALS RESEARCH Volume: 30 Issue: 20 Pages: 2991-3002 Published: OCT 28 2015
    Obtaining highly dense YSZ nanoceramics by pressureless, unassisted sintering By: Hotza, Dachamir; Garcia, Daniel E.; Castro, Ricardo H. R. INTERNATIONAL MATERIALS REVIEWS Volume: 60 Issue: 7 Pages: 353-375 Published: OCT 2015
    Energetics of Oriented Attachment of Mn-Doped SnO2 Nanoparticles By: Chang, Chi-Hsiu; Dey, Sanchita; Castro, Ricardo H. R. JOURNAL OF PHYSICAL CHEMISTRY C Volume: 119 Issue: 35 Pages: 20662-20672 Published: SEP 3 2015
    Modeling grain growth kinetics of binary substitutional alloys by the thermodynamic extremal principle By: Gong, M. M.; Castro, R. H. R.; Liu, F. JOURNAL OF MATERIALS SCIENCE Volume: 50 Issue: 13 Pages: 4610-4621 Published: JUL 2015
    Phase Stability in Nanocrystals: A Predictive Diagram for Yttria-Zirconia By: Drazin, John W.; Castro, Ricardo H. R. JOURNAL OF THE AMERICAN CERAMIC SOCIETY Volume: 98 Issue: 4 Pages: 1377-1384 Published: APR 2015
    Thermodynamic Stability of SnO2 Nanoparticles: The Role of Interface Energies and Dopants By: Chang, Chi-Hsiu; Gong, Mingming; Dey, Sanchita; et al. JOURNAL OF PHYSICAL CHEMISTRY C Volume: 119 Issue: 11 Pages: 6389-6397 Published: MAR 19 2015
    Water Adsorption Microcalorimetry Model: Deciphering Surface Energies and Water Chemical Potentials of Nanocrystalline Oxides By: Drazin, John W.; Castro, Ricardo H. R. JOURNAL OF PHYSICAL CHEMISTRY C Volume: 118 Issue: 19 Pages: 10131-10142 Published: MAY 15 2014
    Surface and grain boundary energies of tin dioxide at low and high temperatures and effects on densification behavior By: Chang, Chi-Hsiu; Castro, Ricardo H. R. JOURNAL OF MATERIALS RESEARCH Volume: 29 Issue: 9 Pages: 1034-1046 Published: MAY 14 2014
    Design of Desintering in Tin Dioxide Nanoparticles By: Chang, Chi-Hsiu; Rufner, Jorgen F.; van Benthem, Klaus; et al. CHEMISTRY OF MATERIALS Volume: 25 Issue: 21 Pages: 4262-4268 Published: NOV 12 2013
Nanomaterials can potentially present higher radiaton tolerance
Nanostructured materials are likely to play a large role in future nuclear reactors and radioactive waste storage due to their strength and potential resistance to structural damage from radiation. However, this potential is hindered by significant gaps in the understanding of interfaces' properties and their role in the overall performance of the nanocrystalline structures. The lack of reliable thermodynamical data of nanomaterials makes it extremely difficult to predict and fully exploit nanomaterials' properties in high-radiation environments, this being one of the major reasons why the stability of the nanomaterials is still a big unresolved question. The goal of this project is to investigate nanomaterials with potential interest for nuclear components [the aluminate based spinels (MAl2O4, M = Mg, Ni, or Zn), investigate zirconia based materials (ZrO2 doped with Mg, Y, or Ca), and establish the link between composition, interface thermodynamics, and radiation resistance, aiming to enable a better understanding of the nature of enhanced performance in nanocrystalline ceramics. Thereafter, we will exploit the achieved knowledge as a foundation in order to design a new nanocomposite ceramic capable of withstanding high radiation exposition by using elements of interface engineering on a thermodynamic basis. This project is in collaboration with the Los Alamos National Laboratory and is supported by the US Department of Energy, division of Basic Energy Sciences. Materials Design Institute also support a parallel research. In an independent effort, we are trying to identify the role of the nanoscale in CeO2 nanostructures, and if it is possible to improve radiation tolerance of CeO2 upon doping with Mn. This work is supported by UC LabFee.
Some related publications:
    Radiation Tolerance of Nanocrystalline Ceramics: Insights from Yttria Stabilized Zirconia By: Dey, Sanchita; Drazin, John W.; Wang, Yongqiang; et al. SCIENTIFIC REPORTS Volume: 5 Article Number: 7746 Published: JAN 13 2015
    Irradiation-induced grain growth and defect evolution in nanocrystalline zirconia with doped grain boundaries By: Dey, Sanchita; Mardinly, John; Wang, Yongqiang; et al. PHYSICAL CHEMISTRY CHEMICAL PHYSICS Volume: 18 Issue: 25 Pages: 16921-16929 Published: JUL 7 2016
    Improving the Thermodynamic Stability of Aluminate Spinel Nanoparticles with Rare Earths By: Hasan, Md M.; Dey, Sanchita; Nafsin, Nazia; et al. CHEMISTRY OF MATERIALS Volume: 28 Issue: 14 Pages: 5163-5171 Published: JUL 26 2016
    Stabilization of MgAl2O4 spinel surfaces via doping By: Hasan, Md. M.; Dholabhai, Pratik P.; Castro, Ricardo H. R.; et al. SURFACE SCIENCE Volume: 649 Pages: 138-145 Published: JUL 2016
    Phase Stability in Calcia-Doped Zirconia Nanocrystals By: Drazin, John W.; Castro, Ricardo H. R. JOURNAL OF THE AMERICAN CERAMIC SOCIETY Volume: 99 Issue: 5 Pages: 1778-1785 Published: MAY 2016


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SHPE - Society of Hispanic Professional Engineers.
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I'm a scientist with faith. Learn more about Castro's faith and how science can co-exist with God.