Scientists at Oak Ridge National Laboratory have made significant strides in the study of the rare earth element promethium, first discovered at the laboratory 80 years ago. Promethium’s properties have remained largely elusive, despite its use in medical studies and nuclear batteries. An ORNL-led team successfully characterized promethium in solution for the first time, shedding light on the properties of this rare lanthanide element with atomic number 61.
The team’s research, published in the journal Nature, represents a major breakthrough in rare earth element studies that could rewrite chemistry textbooks. Promethium, with no stable isotopes, was the last lanthanide to be discovered and has posed challenges for researchers due to its scarcity and limited study. By producing promethium-147 in sufficient quantities, the team was able to study its chemical properties and observe a feature of lanthanide contraction, a phenomenon where elements between atomic numbers 57 and 71 have smaller than expected sizes.
The study utilized unique resources and expertise available at DOE national laboratories, including hot cells, supercomputers, and the knowledge of 18 scientists in various fields. Through chelation of radioactive promethium with diglycolamide ligands and X-ray spectroscopy, the team was able to obtain valuable information about promethium’s properties. The research is a crucial step towards understanding the chemistry of lanthanides and their applications in modern technologies.
The team’s accomplishment will facilitate the separation of valuable lanthanides, an essential step for their utilization in advanced technologies. The inability to effectively separate lanthanides from one another has posed challenges for their application in various fields. The ORNL-led research will aid in this separation process, making it easier to utilize lanthanides in technologies such as cancer treatment, renewable energy, and long-lived nuclear batteries.
The project required the use of several premier DOE facilities, including the High Flux Isotope Reactor at ORNL for promethium synthesis and the National Synchrotron Light Source II at Brookhaven National Laboratory for X-ray absorption spectroscopy. Quantum chemical calculations and molecular dynamics simulations were performed on ORNL’s Summit supercomputer. The collective efforts of the research team, consisting of 18 authors, were essential in achieving this milestone in rare earth element research.
The findings of the study have opened up new possibilities for future research and the application of rare earth elements in modern technology. The team’s work on promethium has filled a gap in the understanding of lanthanides and their properties, paving the way for further exploration. The research highlights the importance of collaboration and the utilization of state-of-the-art resources in scientific endeavors. The study marks a significant advancement in the field of rare earth element research and has the potential to impact a wide range of scientific disciplines.