We seek to control materials functionality and predict materials performance.
Our national security priorities of nuclear deterrence, energy security, and global security demand that the Laboratory be a leader in materials science and engineering.
Prediction of a material’s performance over its lifetime in a complex service environment is critical for accelerating new materials into applications. This pillar requires both “predictable performance,” the ability to reliably and consistently forecast how a material will perform over its lifetime, and “controlled functionality,” the actual design and tailoring of a material’s properties that were previously unattainable or not available with traditional techniques.
Through prototype-to-production manufacturing, Los Alamos invented Pu and U alloys, plastic-bonded explosives, and determined how material properties impact structural and dynamic performance.
Plutonium alloy samples immediately after casting.
Summary
Los Alamos invented a variety of plutonium alloys for our nuclear deterrence mission that have various properties for different mission objectives. The Laboratory also invented plutonium purification processes, and has led pit manufacturing both in the early days of the nuclear program and again, today, as US capacity for pit production is reestablished. Los Alamos has also developed and prototyped innovative manufacturing for uranium alloy components such as the direct cast approach.
Plastic-bonded conventional high explosive PBX 9501, another Lab invention, improved safety in handling and transportation scenarios, while maintaining performance and facilitating compact warhead designs. The Lab was also the first to formulate tri-amino-trinitro-benzene (TATB) into insensitive high explosives (IHE), and to test and field nuclear warheads with IHE—the B61, then the W80 and W85—using PBX 9502.
Contributing authors
Mark Chadwick, Marianne Francois
Integrated Nanomaterials
Los Alamos discovers and develops nanomaterials, integrating them into devices for real-world applications, including quantum dot optical systems and active metamaterials to control light.
Quantum dots (QDs) are semiconductors with dimensions at the nanoscale. The wavelength (color) at which they fluoresce can be tuned by controlling their size with angstrom-level precision. Photo courtesy of the Center for Integrated Nanotechnologies.
Summary
Nanoscale integration involves combining nanoscale materials—with extraordinary physical, chemical, or biological properties—with other materials to amplify their properties or obtain entirely new behaviors. LANL research has targeted the path from scientific discovery to technological impacts, founding the Center for Integrated Nanotechnologies (CINT), a DOE Nanoscale Research Center, in 2006.
LANL scientists lead the way in both photonic devices based on nanocrystal quantum dots (QDs) and functional metamaterials. Work in colloidal nanocrystal QDs has broken ground in synthetic control of nanoscale heterostructures, laser spectroscopy, optical gain, nonlinear optical effects, and multi-carrier phenomena, with applications including quantum dot lasers and single-photon sources.
Artificial metamaterials are engineered around subwavelength structures. LANL leads in metamaterials bridging the “terahertz gap,” inventing photonic devices in a region of the electromagnetic spectrum where natural materials fail and pioneering metamaterials with electrically switchable and tunable functionality, perfect absorption, broadband polarization conversion, nanoscale optoelectronic responses, nonreciprocal transmission/reflection, and on-demand quantum entanglement.
Active terahertz metamaterial devices. H.-T. Chen, W. J. Padilla, J. M. O. Zide, A. C. Gossard, A. J. Taylor, and R. D. Averitt. Nature 444, no. 7119 (2006): 597–600.
Metasurface-based flat optics at terahertz frequencies:
The history of Los Alamos is intimately intertwined with plutonium. Every advance in plutonium science either happened here or was inspired by this Laboratory.
Single crystals of CeCoGa5 and PuCoGa5 compounds that exhibit localized-delocalized f-electron behaviors, a hallmark of highly correlated materials. The cerium compound is a surrogate system for plutonium-based superconductors.
Summary
Plutonium was recognized as the superior fuel for the atomic bomb shortly after its 1940 discovery. The earliest samples varied widely in density, the first clue to plutonium’s complexity. Nonetheless, workable alloys were developed over five short months before April 1945.
Next came the discovery of complex, six-phase crystallography of plutonium, followed by its properties under shock and pressure. The cessation of nuclear testing in 1992 required a much greater understanding of plutonium’s fundamental properties. This resulted in experiments ranging from accelerated aging (using plutonium-238) and dynamic measurements such as gas guns to major innovations in spectroscopy, theory, and modeling.
Practical applications of plutonium science beyond its direct use in weapons and reactors have included solving complex-wide plutonium storage problems, the minimal-waste Advanced Recovery and Integrated Extraction System (ARIES) for plutonium recovery, and insights into environmental plutonium transport that allowed cleanup of Rocky Flats Plant a year ahead of schedule.
Contributing authors
Joe Martz and Dave Clark
References
Turn-of-the century overview of what was then known about plutonium:
Plutonium Aging: From Mystery to Enigma. Hecker, S. Siegfried, and Joseph C. Martz. Proceedings of the Oxford Conference on Aging and Lifetime Extension of Materials (1999).
New Pressure-Temperature Phase Diagram of Plutonium. Morgan, J. R. (1970). Plutonium 1970 and Other Actinides: Proc. 4th Int. Conf. on Plutonium and Other Actinides. W. N. Miner. Santa Fe, New Mexico, Metallurgical Society of the American Institute of Mining, Metallurgical, and Petroleum Engineers: 669-678.
The scientific understanding of the chemistry of plutonium in the environment saved time and taxpayer dollars:
Los Alamos’ discovery of materials dominated by quantum effects, ranging from liquid helium-3 to plutonium metal, is opening the door to future quantum hardware.
Quantum materials often develop new and technologically useful states of matter that emerge from a quantum critical point at zero temperature.
Summary
Los Alamos has shaped the field of materials whose properties are driven by quantum effects—in short, quantum materials. Cryogenic capabilities that led to the first liquefaction of the quantum fluid helium-3 at Los Alamos in 1948 soon thereafter enabled the Ivy Mike thermonuclear test. In the early 80s, LANL scientists discovered superconductivity and magnetism in uranium-based materials with massive electrons produced by electronic correlations. Low-temperature measurements revealed that superconductivity was a new quantum state of matter. These unconventional uranium materials led to the discovery of new heavy-electron plutonium- and cerium-based superconductors and provided the scientific justification for LANL’s pulsed magnetic field facility that produced the first non-destructive magnet fields over 100 Tesla.
Today, we explore how novel quantum materials may lead to tomorrow’s quantum devices while learning how the same electronic correlations that give rise to exotic superconductivity and magnetism are also responsible for the complexity of plutonium metal.
Contributing authors
Filip Ronning and Joe Thompson
References
The early work on Helium-3 and heavy fermions is responsible for perhaps 50% of all quantum materials research world-wide today:
