"An integrated experimental and computational investigation of defect and microstructural effects on thermal transport in thorium dioxide" Marat Khafizov, Lingfeng He, Cody Dennett, David Hurley, Zilong Hua, Amey Khanolkar, Anter EL-AZAB, Kaustubh Bawane, Acta Materialia Vol. 213 2021 Link | ||
"Inferring Relative Dose-dependent Color Center Populations in Proton Irradiated Thoria Single Crystals using Optical Spectroscopy" Marat Khafizov, Amey Khanolkar, David Hurley, Cody Dennett, Zilong Hua, James Mann, Physical Chemistry Chemical Physics Vol. 24 2022 Link |
"Influence of Irradiation-induced Microstructural Defects on the Thermal Conductivity of Single Crystal Thorium Dioxide" Marat Khafizov, Amey Khanolkar, Zilong Hua, Cody Dennett, wangthink Wang, Tiankai Yao, Lingfeng He, Jian Gan, David Hurley, TMS 2020 February 23-27, (2020) |
"Effects of irradiation damage on the hardness and elastic properties of quaternary and high entropy transition metal diborides"
Amit Datye, Yan Zhang, Cody A. Dennett, Weiming Guo, Yang Liu, William J. Weber, Hua-Tay Lin, Yanwen Zhang, Amey Khanolkar,
[2024]
Journal of Applied Physics
· DOI: 10.1063/5.0206224
Multi-principal component transition metal (TM) diborides represent a class of high-entropy ceramics (HECs) that have received considerable interest in recent years owing to their promising properties for extreme environment applications that include thermal/ environmental barriers, hypersonic vehicles, turbine engines, and next-generation nuclear reactors. While the addition of chemical disorder through the random distribution of TM elements on the cation sublattice has offered opportunities to tailor elastic stiffness and hardness, the effects of irradiation-induced structural damage on the physical properties of these complex materials have remained largely unexplored. To this end, changes in the hardness and elastic moduli of a high-entropy TM diboride (Hf0.2Nb0.2Ta0.2Ti0.2Zr0.2)B2 and three of its quaternary subsets following irradiation with 10 MeV gold (Au) ions to fluences of up to 6 × 1015 Au cm−2 are investigated at the micrometer and sub-micrometer length-scales via the dispersion of laser-generated surface acoustic waves (SAW) and nanoindentation, respectively. The nanoindentation measurements show that the TM diborides exhibit an initial increase in hardness following irradiation with energetic Au ions, with a subsequent decrease in hardness following further irradiation. One quaternary composition, (Hf1/3Ta1/3Ti1/3)B2, exhibits a notable exception to the trend and continues to exhibit an increase in hardness with ion irradiation fluence. Although differences in the absolute values of the effective elastic moduli obtained from the measured SAW dispersion and nanoindentation are observed (and attributed to microstructural variations at the measurement length-scale), both techniques yield similar trends in the form of an initial reduction and subsequent saturation in the elastic modulus with increasing ion irradiation fluence. The quaternary TM diboride (Hf1/3Ta1/3Ti1/3)B2 again exhibits a departure from this trend. The high-entropy TM diboride (Hf0.2Nb0.2Ta0.2Ti0.2Zr0.2)B2 exhibits the greatest recovery in hardness and modulus when irradiated to high ion fluences following initial changes at low fluence, indicating superior resistance to radiation-induced damage over its quaternary counterparts. Opportunities for designing HECs with superior hardness and modulus for enhanced radiation resistance (compared to their single constituent counterparts) by tailoring chemical disorder and bond character in the lattice are discussed. |
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"Thermal conductivity suppression in uranium-doped thorium dioxide due to phonon-spin interactions" Saqeeb Adnan, Amey R. Khanolkar, Karl Rickert, David B. Turner, Timothy A. Prusnick, J. Matthew Mann, David H. Hurley, Marat Khafizov, Cody A. Dennett, Zilong Hua, [2024] Journal of Materiomics · DOI: 10.1016/j.jmat.2023.11.007 | |
"Temperature-dependent elastic constants of thorium dioxide probed using time-domain Brillouin scattering"
Yuzhou Wang, Cody A. Dennett, Zilong Hua, J. Matthew Mann, Marat Khafizov, David H. Hurley, Amey Khanolkar,
[2023]
Journal of Applied Physics
· DOI: 10.1063/5.0148866
We report the adiabatic elastic constants of single-crystal thorium dioxide over a temperature range of 77–350 K. Time-domain Brillouin scattering, an all-optical, non-contact picosecond ultrasonic technique, is used to generate and detect coherent acoustic phonons that propagate in the bulk perpendicular to the surface of the crystal. These coherent acoustic lattice vibrations have been monitored in two hydrothermally grown single-crystal thorium dioxide samples along the (100) and (311) crystallographic directions. The three independent elastic constants of the cubic crystal (C11, C12, and C44) are determined from the measured bulk acoustic velocities. The longitudinal wave along the (100) orientation provided a direct measurement of C11. Measurement of C44 and C12 was achieved by enhancing the intensity of quasi-shear mode in a (311) oriented crystal by adjusting the polarization angle relative to the crystal axes. We find the magnitude of softening of the three elastic constants to be ∼2.5% over the measured temperature range. Good agreement is found between the measured elastic constants with previously reported values at room temperature, and between the measured temperature-dependent bulk modulus with calculated values. We find that semi-empirical models capturing lattice anharmonicity adequately reproduce the observed trend. We also determine the acoustic Grüneisen anharmonicity parameter from the experimentally derived temperature-dependent bulk modulus and previously reported temperature-dependent values of volumetric thermal expansion coefficient and heat capacity. This work presents measurements of the temperature-dependent elasticity in single-crystal thorium dioxide at cryogenic temperature and provides a basis for testing ab initio theoretical models and evaluating the impact of anharmonicity on thermophysical properties. |
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"Detecting Thermally-Induced Spinodal Decomposition with Picosecond Ultrasonics in Cast Austenitic Stainless Steels" Benjamin Reid Dacus, Cody A. Dennett, M. Grace Burke, Lawrence Waldron, Thak Sang Byun, James J. Wall, Kuba Bar-Din Anglin, Omar Abdulfattah Ahmed Al Dajani, Konrad J. Krakowiak, Franz.-J. Ulm, Alan Schwartzmann, C. Cem Tasan, Peter Hosemann, Michael Philip Short, Saleem Abdulfattah Ahmed Al Dajani, [2023] Acta Materialia · DOI: 10.1016/j.actamat.2022.118552 | |
"Advances in actinide thin films: synthesis, properties, and future directions"
Firoza Kabir, Narayan Poudel, Chris A Marianetti, David H Hurley, Paul J Simmonds, Cody A Dennett, Krzysztof Gofryk, Kevin D Vallejo,
[2022]
Reports on Progress in Physics
· DOI: 10.1088/1361-6633/ac968e
Actinide-based compounds exhibit unique physics due to the presence of 5f electrons, and serve in many cases as important technological materials. Targeted thin film synthesis of actinide materials has been successful in generating high-purity specimens in which to study individual physical phenomena. These films have enabled the study of the unique electron configuration, strong mass renormalization, and nuclear decay in actinide metals and compounds. The growth of these films, as well as their thermophysical, magnetic, and topological properties, have been studied in a range of chemistries, albeit far fewer than most classes of thin film systems. This relative scarcity is the result of limited source material availability and safety constraints associated with the handling of radioactive materials. Here, we review recent work on the synthesis and characterization of actinide-based thin films in detail, describing both synthesis methods and modeling techniques for these materials. We review reports on pyrometallurgical, solution-based, and vapor deposition methods. We highlight the current state-of-the-art in order to construct a path forward to higher quality actinide thin films and heterostructure devices. |
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"A combined theoretical-experimental investigation of thermal transport in low-dose irradiated thorium dioxide" Amey Khanolkar, Sanjoy Mazumder, Cody A. Dennett, Kaustubh Bawane, Zilong Hua, Joshua Ferrigno, Lingfeng He, J. Matthew Mann, Marat Khafizov, David H. Hurley, Anter El-Azab, W. Ryan Deskins, [2022] Acta Materialia · DOI: 10.1016/j.actamat.2022.118379 | |
"Validating first-principles phonon lifetimes via inelastic neutron scattering" Hao Ma, Matthew S. Bryan, Lyuwen Fu, J. Matthew Mann, Barry Winn, Douglas L. Abernathy, Raphaël P. Hermann, Amey R. Khanolkar, Cody A. Dennett, David H. Hurley, Michael E. Manley, Chris A. Marianetti, Enda Xiao, [2022] Physical Review B · DOI: 10.1103/physrevb.106.144310 | |
"Thermal conductivity reduction in (Zr0.25Ta0.25Nb0.25Ti0.25)C high entropy carbide from extrinsic lattice defects" Zilong Hua, Eric Lang, Fei Wang, Bai Cui, Cody A. Dennett, [2022] Materials Research Letters · DOI: 10.1080/21663831.2022.2078678 | |
"Impact of small defects and dislocation loops on phonon scattering and thermal transport in ThO2" Cody A. Dennett, David H. Hurley, Marat Khafizov, Miaomiao Jin, [2022] Journal of Nuclear Materials · DOI: 10.1016/j.jnucmat.2022.153758 | |
"Thermal diffusivity recovery and defect annealing kinetics of self-ion implanted tungsten probed by insitu transient grating spectroscopy" Guanze He, Cody A. Dennett, Hongbing Yu, Kenichiro Mizohata, Felix Hofmann, Abdallah Reza, [2022] Acta Materialia · DOI: 10.1016/j.actamat.2022.117926 | |
"Unraveling small-scale defects in irradiated ThO2 using kinetic Monte Carlo simulations" Lingfeng He, Cody A. Dennett, Marat Khafizov, J. Matthew Mann, David H. Hurley, Chao Jiang, [2022] Scripta Materialia · DOI: 10.1016/j.scriptamat.2022.114684 | |
"Towards actinide heterostructure synthesis and science" Narayan Poudel, Paul J. Simmonds, Ashutosh Tiwari, David H. Hurley, Krzysztof Gofryk, Cody A. Dennett, [2022] Nature Communications · DOI: 10.1038/s41467-022-29817-0 | |
"The In Situ Ion Irradiation Toolbox: Time-Resolved Structure and Property Measurements"
C. A. Dennett, N. Madden, K. Hattar, E. Lang,
[2022]
JOM
· DOI: 10.1007/s11837-021-04993-4
The dynamic interactions of ions with matter drive a host of complex evolution mechanisms, requiring monitoring on short spatial and temporal scales to gain a full picture of a material response. Understanding the evolution of materials under ion irradiation and displacement damage is vital for many fields, including semiconductor processing, nuclear reactors, and space systems. Despite materials in service having a dynamic response to radiation damage, typical characterization is performed post-irradiation, washing out all information from transient processes. Characterizing active processes in situ during irradiation allows the mechanisms at play during the dynamic ion-material interaction process to be deciphered. In this review, we examine the in situ characterization techniques utilized for examining material structure, composition, and property evolution under ion irradiation. Covering analyses of microstructure, surface composition, and material properties, this work offers a perspective on the recent advances in methods for in situ monitoring of materials under ion irradiation, including a future outlook examining the role of complementary and combined characterization techniques in understanding dynamic materials evolution. |
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"Inferring relative dose-dependent color center populations in proton irradiated thoria single crystals using optical spectroscopy"
Cody A. Dennett, Zilong Hua, J. Matthew Mann, David H. Hurley, Marat Khafizov, Amey Khanolkar,
[2022]
Physical Chemistry Chemical Physics
· DOI: 10.1039/d1cp05191a
Transparent thoria crystals developed a deep blue color when exposed to energetic protons due to electrons trapped at oxygen vacancy sites. Optical spectroscopy offers a promising pathway to characterize the population of such atomic-level defects that cannot be imaged using electron microscopy. |
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"An integrated experimental and computational investigation of defect and microstructural effects on thermal transport in thorium dioxide" W. Ryan Deskins, Marat Khafizov, Zilong Hua, Amey Khanolkar, Kaustubh Bawane, Lyuwen Fu, J. Matthew Mann, Chris A. Marianetti, Lingfeng He, David H. Hurley, Anter El-Azab, Cody A. Dennett, [2021] Acta Materialia · DOI: 10.1016/j.actamat.2021.116934 | |
"The influence of lattice defects, recombination, and clustering on thermal transport in single crystal thorium dioxide"
Zilong Hua, Amey Khanolkar, Tiankai Yao, Phyllis K. Morgan, Timothy A. Prusnick, Narayan Poudel, Aaron French, Krzysztof Gofryk, Lingfeng He, Lin Shao, Marat Khafizov, David B. Turner, J. Matthew Mann, David H. Hurley, Cody A. Dennett,
[2020]
APL Materials
· DOI: 10.1063/5.0025384
Thermal transport is a key performance metric for thorium dioxide in many applications where defect-generating radiation fields are present. An understanding of the effect of nanoscale lattice defects on thermal transport in this material is currently unavailable due to the lack of a single crystal material from which unit processes may be investigated. In this work, a series of high-quality thorium dioxide single crystals are exposed to 2 MeV proton irradiation at room temperature and 600 °C to create microscale regions with varying densities and types of point and extended defects. Defected regions are investigated using spatial domain thermoreflectance to quantify the change in thermal conductivity as a function of ion fluence as well as transmission electron microscopy and Raman spectroscopy to interrogate the structure of the generated defects. Together, this combination of methods provides important initial insight into defect formation, recombination, and clustering in thorium dioxide and the effect of those defects on thermal transport. These methods also provide a promising pathway for the quantification of the smallest-scale defects that cannot be captured using traditional microscopy techniques and play an outsized role in degrading thermal performance. |
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"Non-contact, non-destructive mapping of thermal diffusivity and surface acoustic wave speed using transient grating spectroscopy"
Cody A. Dennett, Michael P. Short, John Waite, Yevhen Zayachuk, Christopher M. Magazzeni, Simon Hills, Felix Hofmann, Abdallah Reza,
[2020]
Review of Scientific Instruments
· DOI: 10.1063/5.0003742
We present new developments of the laser-induced transient grating spectroscopy (TGS) technique that enable the measurement of large area 2D maps of thermal diffusivity and surface acoustic wave speed. Additional capabilities include targeted measurements and the ability to accommodate samples with increased surface roughness. These new capabilities are demonstrated by recording large TGS maps of deuterium implanted tungsten, linear friction welded aerospace alloys, and high entropy alloys with a range of grain sizes. The results illustrate the ability to view the grain microstructure in elastically anisotropic samples and to detect anomalies in samples, for example, due to irradiation and previous measurements. They also point to the possibility of using TGS to quantify grain size at the surface of polycrystalline materials. |
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"Listening to Radiation Damage In Situ: Passive and Active Acoustic Techniques" R. Charles Choens, Caitlin A. Taylor, Nathan M. Heckman, Mathew D. Ingraham, David Robinson, Brad L. Boyce, Michael P. Short, Khalid Hattar, Cody A. Dennett, [2020] JOM · DOI: 10.1007/s11837-019-03898-7 | |
"Inferring radiation-induced microstructural evolution in single-crystal niobium through changes in thermal transport" Cody A. Dennett, Kevin B. Woller, Michael P. Short, Sara E. Ferry, [2019] Journal of Nuclear Materials · DOI: 10.1016/j.jnucmat.2019.06.015 · ISSN: 0022-3115 | |
"Transient grating spectroscopy: An ultrarapid, nondestructive materials evaluation technique" Michael P. Short, Cody A. Dennett, Felix Hofmann, [2019] MRS Bulletin · DOI: 10.1557/mrs.2019.104 · ISSN: 0883-7694 | |
"Real-time thermomechanical property monitoring during ion beam irradiation using in situ transient grating spectroscopy" Daniel L. Buller, Khalid Hattar, Michael P. Short, Cody A. Dennett, [2019] Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms · DOI: 10.1016/j.nimb.2018.10.025 · ISSN: 0168-583X | |
"Conceptual design study for heat exhaust management in the ARC fusion pilot plant" N.M. Cao, A.J. Creely, C.A. Dennett, J. Hecla, B. LaBombard, R.A. Tinguely, E.A. Tolman, H. Hoffman, M. Major, J. Ruiz Ruiz, D. Brunner, P. Grover, C. Laughman, B.N. Sorbom, D.G. Whyte, A.Q. Kuang, [2018] Fusion Engineering and Design · DOI: 10.1016/j.fusengdes.2018.09.007 | |
"Thermal diffusivity determination using heterodyne phase insensitive transient grating spectroscopy" Michael P. Short, Cody A. Dennett, [2018] Journal of Applied Physics · DOI: 10.1063/1.5026429 | |
"Detecting self-ion irradiation-induced void swelling in pure copper using transient grating spectroscopy" K.P. So, A. Kushima, D.L. Buller, K. Hattar, M.P. Short, C.A. Dennett, [2018] Acta Materialia · DOI: 10.1016/j.actamat.2017.12.007 | |
"Erratum: “Time-resolved, dual heterodyne phase collection transient grating spectroscopy” [Appl. Phys. Lett. 110, 211106 (2017)]" Michael P. Short, Cody A. Dennett, [2017] Applied Physics Letters · DOI: 10.1063/1.5006318 | |
"Bridging the gap to mesoscale radiation materials science with transient grating spectroscopy" Penghui Cao, Sara E. Ferry, Alejandro Vega-Flick, Alexei A. Maznev, Keith A. Nelson, Arthur G. Every, Michael P. Short, Cody A. Dennett, [2016] Physical Review B - Condensed Matter and Materials Physics · DOI: 10.1103/physrevb.94.214106 · EID: 2-s2.0-85006265545 | |
"Applications of Transient Grating Spectroscopy to Radiation Materials Science" Cody A. Dennett, Sara E. Ferry, Yang Yang, Vikash K. Mishra, Jeffrey K. Eliason, Alejandro Vega-Flick, Alexei A. Maznev, Keith A. Nelson, Michael P. Short, [2015] JOM · DOI: 10.1007/s11837-015-1496-3 · EID: 2-s2.0-84938963107 | |
"In-situ measurements of the secondary electron yield in an accelerator environment: Instrumentation and methods" D.M. Asner, J.V. Conway, C.A. Dennett, S. Greenwald, J.-S. Kim, Y. Li, T.P. Moore, V. Omanovic, M.A. Palmer, C.R. Strohman, W.H. Hartung, [2015] Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment · DOI: 10.1016/j.nima.2015.01.092 · EID: 2-s2.0-84924769496 | |
"Measurements of secondary electron yield of metal surfaces and films with exposure to a realistic accelerator environment" [2013] IPAC 2013: Proceedings of the 4th International Particle Accelerator Conference · EID: 2-s2.0-84890599315 | |
Source: ORCID/CrossRef using DOI |
The Nuclear Science User Facilities (NSUF) is the U.S. Department of Energy Office of Nuclear Energy's only designated nuclear energy user facility. Through peer-reviewed proposal processes, the NSUF provides researchers access to neutron, ion, and gamma irradiations, post-irradiation examination and beamline capabilities at Idaho National Laboratory and a diverse mix of university, national laboratory and industry partner institutions.
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