Peter C. Burns

3D Models of nanoclusters

The plastic 3D models of uranyl peroxide nanoclusters shown to the left were printed using ABS or PLA plastic and an UP! Mini, Flashforge Creator, or Makerbot Replicator 2 printer. The larger models are approximately 15 cm diameter.

Digital files were created using Crystalmaker 9.0, starting from the Crystallographic Information Files (CIF). The complete 3D computer model was exported from Crystalmaker as a DAE file, which was subsequently converted to an STL file before being imported into the printer control software.

Printing these models requires inclusion of significant supports that are removed by hand following completion. Printing a high-quality U60 model, as seen on the left, requires approximately 24 hours of printer time.

STL files are available by request (pburns@nd.edu)

Graduate studies opportunities in the burns group

Graduate Studies in Actinide Chemistry

Graduate Studies in Radiochemistry

Graduate Studies in Mineralogy

Graduate Studies in Geochemistry

Graduate Studies in Actinide Materials

Graduate Studies in Actinide Crystallography

nuclear forensics

Nuclear materials used in weapons carry detectable chemical and isotopic signatures that may be useful for attribution. We are developing approaches for characterizing material that results from a nuclear weapon blast (post-detonation debris) so that it will be possible to determine the type of device used and its origin.

Actinide Materials in Extreme Environments

We study nanoscale actinide materials and their response to high pressure, high temperature and intense irradiation to understand performance of materials over a broad range of real-world conditions. We use in situ probes to characterize material under extreme conditions in reaction vessels (T) and diamond anvil cells (P). We emphasize the behaviors of actinide materials subjected to extreme doses of gamma (from Co source) and alpha (from ion accelerators) radiation.   

Metal organic frameworks (MOFs) have received intense interest in chemistry owing to their unique porous structures with important applications. We are emphasizing producing novel MOFs containing metal oxide nodes containing Th, U and Np. 

We are interested in the complex topologies of inorganic actinide compounds, and specifically how the various structural units and interstitial complexes combine to form a wide range of natural and synthetic materials. We have arranged U(VI), Np(V) and Np(VI) compounds into structural hierarchies based on structural units, and developed graphical and anion-topology approaches to study their relationships.

We study uranium mineralogy and crystallography, as well as general mineralogy of interesting mineral groups. Our emphasis is on the structures, compositions, and occurrences of minerals, and relating the crystal structures to stabilities and mineral occurrences. We have co-discovered and named several fascinating uranyl minerals in recent years: krouptaite (2020), redcanyonite (2018), paddlewheelite (2018), leesite (2018), ewingite (2017), leoszilardite (2017), gauthierite (2017).

Research Overview

Our research focuses on many aspects of actinides, including their materials science, mineralogy, geochemistry, environmental transport, nanoscale control, and aspects of national security. We study natural uranium and thorium minerals, and a broad range of materials that we synthesize containing thorium, uranium, neptunium, or plutonium. We use many diffraction, scattering, and spectroscopic techniques to study actinides at various length scales.

In 2005 we discovered how to create the conditions for a complex family of nanoscale uranyl peroxide cage clusters to form spontaneously in aqueous solution. We crystallize these clusters for structure determination using X-ray diffraction, and study their properties in solution using DLS, SAXS, and ESI-MS. We have created and characterized more than 100 varieties of cage clusters that contain a broad range of chemical constituents. These clusters provide a unique and powerful library of models for studying structure-size-property relations, as well as a means of controlling uranium in solution on the scale of several nanometers, which places them intermediate in size between solid materials and dissolved cations. Possible applications include environmentally superior methods for nuclear fuel recycling and fabrication of nanocomposite nuclear fuels with accident resistant properties.

Expansion of actinide cluster chemistry into the transuranium elements holds promise for revealing the role of 5f electrons in bonding and properties. 

We study the inorganic controls of Np(V) mobility in the subsurface. Specifically, we are probing the extent to which Np(V) is co-precipitated into a variety of low-temperature minerals, where it can substitute at different cation sites or in interstitial locations.

Thermodynamics of actinide materials

We have developed a unique and extremely powerful suite of calorimetric tools for the study of actinide materials. These include multiple high-temperature drop solution and mixing calorimeters that are dedicated to our actinide research. Determination of thermodynamic properties of materials is essential for understanding their stabilities and phase relations in applications, the environment, and geologic repositories for nuclear waste.