Optical Vibrational Spectroscopic Investigation of Natural and Synthetic Analogs of Uranyl Oxyhydroxyhydrate Minerals

Barth, Brodie [ORNL] (ORCID:0000000256142601); Kaitschuck, Nick [ORNL]; Felton, Daniel [ORNL] (ORCID:0000000305082466); Olds, Travis A [Section of Minerals and Earth Sciences, Carnegie Museum of Natural History]; Burns, Peter [University of Notre Dame, IN]; Miskowiec, Andrew [ORNL] (ORCID:0000000203612614); Spano, Tyler [ORNL] (ORCID:0000000165729722)

doi:10.2138/am-2025-10112

DOE OSTI · 3740806

Optical Vibrational Spectroscopic Investigation of Natural and Synthetic Analogs of Uranyl Oxyhydroxyhydrate Minerals

Barth, Brodie [ORNL] (ORCID:0000000256142601)·Kaitschuck, Nick [ORNL]·Felton, Daniel [ORNL] (ORCID:0000000305082466)·Olds, Travis A [Section of Minerals and Earth Sciences, Carnegie Museum of Natural History]·Burns, Peter [University of Notre Dame, IN]·Miskowiec, Andrew [ORNL] (ORCID:0000000203612614)·Spano, Tyler [ORNL] (ORCID:0000000165729722)

View original source ↗Read source document ↗Export metadata ↓

Abstract

Uranyl oxy-hydroxy-hydrate minerals are common alteration products of uraninite (UO2+x) which is chemically and structurally analogous to uranium dioxide nuclear fuel. Therefore, structural and spectroscopic investigations of these alteration minerals and their analogous anthropogenic counterparts can provide insight into the environmental behavior of nuclear fuel cycle materials. Previously, we compiled available vibrational spectroscopic data for uranyl minerals in the Compendium of Uranium Raman and Infrared Experimental Spectra (CURIES) and found that only 37% of known uranyl oxy-hydroxy-hydrate minerals had spectra readily available in the literature and existing databases for inclusion therein. Furthermore, no available infrared spectra for this mineral group were included in CURIES. To expand our understanding of the spectroscopic features of uranyl oxy-hydroxy-hydrates and the structural origins thereof, we collected, and now include in CURIES, Raman and infrared spectra for an additional 12 uranyl hydroxide phases. To better understand the impact of structural and compositional variations of these phases on their spectroscopic features, we compare Raman spectra of different anion sheet topological groups and of analogous phases hosting different counter cations. We identify spectroscopic variations related to differences in equatorial bonding and structural changes as a result of cation substitution. We also prepare a uranyl hydroxide phase via hydrolysis of uranyl fluoride (UO2F2) as an analog of hydrolysis reactions that occur in nuclear fuel cycle materials; and we find that the alteration product of UO2F2, despite chemical and structural similarities to uranyl oxy-hydroxy-hydrate minerals, is readily distinguishable from related mineral phases using Raman spectroscopy. In this work, we provide new insights into the structural origins of spectroscopic features in uranyl oxy-hydroxy-hydrate minerals, improve the average Raman spectrum for this group of minerals, and thereby improve capabilities for identifying these mineral species and related anthropogenic phases using Raman spectroscopy.

Keep this discovery

BibTeX RIS

Barth, Brodie [ORNL] (ORCID:0000000256142601), Kaitschuck, Nick [ORNL], Felton, Daniel [ORNL] (ORCID:0000000305082466), Olds, Travis A [Section of Minerals and Earth Sciences, Carnegie Museum of Natural History], Burns, Peter [University of Notre Dame, IN], Miskowiec, Andrew [ORNL] (ORCID:0000000203612614), Spano, Tyler [ORNL] (ORCID:0000000165729722). 2026-04-01. Optical Vibrational Spectroscopic Investigation of Natural and Synthetic Analogs of Uranyl Oxyhydroxyhydrate Minerals. https://doi.org/10.2138/am-2025-10112

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related reports

NASA NTRSDate not supplied

MEAD In-situ Sampling and Testing at Haughton Crater

The Mars Exploration through Analog-site Drilling (MEAD) project is designed to demonstrate the feasibility and scientific value of robotic drilling missions to Mars in the search for evidence of past or extant life. MEAD conducts high-fidelity field simulations integrating drilling, autonomous operations, and in-situ life-detection and mineralogical instruments. The project tests the Signs of Life Detector (SOLID), proposed for the 2019 Discovery Mars Icebreaker mission, and ARIA (Astronaut Raman Instrument for ISRU and Astrobiology), which provides mineral identification and detects trace organics and volatiles, including indicators of organic thermal maturity. Because current and planned Mars drilling missions operate largely “blind,” MEAD also evaluates the use of drill-induced vibrations recorded by deployed geophones to enable local subsurface mapping for improved targeting of drilling and sampling. In August 2025, MEAD completed its first-year field deployment to Haughton Crater in the Canadian High Arctic, an established Mars impact-crater terrestrial analog site, bringing a Honeybee Robotics TRIDENT drill with applied automation, alongside ARIA, SOLID, and FleetSpace geophones.

Haughton Crater↗

DOE OSTI2026

Forensic characterization of surrogate nuclear explosion debris: radiochemical and spectroscopic strategies for method validation

Surrogate nuclear explosion debris (SNED) has emerged as a critical platform for advancing post-detonation nuclear forensic analysis in the absence of readily accessible historic materials. SNED enables controlled investigation and validation of analytical methodologies used to interrogate the chemical, isotopic, radiological, and microstructural signatures preserved in nuclear explosion debris. This review presents an integrated assessment of destructive and non-destructive analytical techniques commonly employed within decision-driven nuclear forensic workflows. Each technique is discussed individually while highlighting how it contributes to different stages of post-detonation analysis. Core methods – including gamma and alpha spectrometry, ICP-MS, TIMS, SIMS, SEM-EDS, XRF, LIBS, vibrational spectroscopy, and X-ray absorption spectroscopy – are critically evaluated with respect to forensic maturity, information content, and matrix limitations. Emphasis is placed on the role of SNED in benchmarking multi-modal workflows and identifying gaps in reproducing heterogeneity, fractionation, and radiation-driven evolution relevant to forensic attribution.

X-ray spectroscopic methods↗

DOE OSTI2026

NOx mediated formation of ε – UO 3 during thermal decomposition of uranyl nitrate hexahydrate under static air conditions

The thermal decomposition of uranyl nitrate hexahydrate in air at temperatures of 650 – 800 °C is expected to yield α – U 3 O 8 through intermediate UO 3 phases. Here, n this study, Raman spectroscopy complimented by powder X-ray diffraction revealed the unexpected formation of ε – UO 3 as an accompanying phase during thermal decomposition of UNH at 700 °C under static air conditions. Experiments demonstrated that ε – UO 3 does not form during the initial ramp up stage nor during the high temperature heating period; but instead forms during the cooling stage between 250 – 400 °C. Additional experiments revealed that UNH initially decomposes through an amorphous UO 3 intermediate prior to α – U 3 O 8 formation. Attempts to bypass the U 3 O 8 precursor in the formation of ε – UO 3 were unsuccessful, supporting the necessity of U 3 O 8 (α – U 3 O 8 in this study) in the formation of ε – UO 3 . The observed phase evolution is proposed to result from the NOx species generated during UNH thermal decomposition, which create localized oxidizing conditions within the furnace under static air conditions. Furthermore, a predominantly phase pure ε – UO 3 was synthesized under static air conditions through the addition of an extra plateau at 250 °C during the cooling step. These findings demonstrate the importance of gas-phase chemistry and cooling conditions in uranium oxide phase evolution and provide additional insight into ε – UO 3 formation pathways.

Epsilon uranium trioxide↗