Coming straight from the University of California Irvine, Dr. Martha Mecarthney shared recent developments made in the world of materials engineering. Dr. Mecarthney and her teams most recent project involved the investigation of monazite ceramics and their potential applications.
Ceramics are a widely used material due to their insulating properties and their relative durability. Apart from the familiar cup-of-‘Joe’ variety, ceramics have been developed to withstand extreme temperatures and stress. These types of material are often used in industry due to the wide range of uses they possess.
Recently, researchers from the University of California explored the potential of a new ceramic made of monazite. Monazite is a term used to describe a phosphate based mineral that is combined with a rare earth metal. The term Monazite comes from the Greek ‘mono’, or to be alone, possibly referring to its rarity in the natural world. The particular variation of monazite that Dr. Mecarthney and her team are working on is lanthanum phosphate.
Lanthanum phosphate follows a strange bonding pattern that gives it its unique properties. The lanthanum sites are each connected to nine different oxygen molecules, with each bond containing a different bond length. This structure allows the molecule to accommodate a wide selection of elements. Also, lanthanum phosphate has the extraordinary ability to, at relatively low temperatures, recover from radiation damage by a self-healing technique. This explains that, when found in nature, the mineral is highly irradiated yet still remains in a solid state with a strong, crystalline structure. At extremely high temperatures, the mineral becomes less soluble and has major plasticity. Due to its structure and prized qualities, lanthanum phosphate is a perfect candidate for Dr. Mecarthney’s research.
Nuclear energy, being the focus of Dr. Mecarthney’s lecture, provides large quantities of energy, but generates a significant amount of heat. The extreme temperatures cause the matrix holding the fuel to become brittle, thus limiting operations and energy output. Dr. Mecarthney and her team suggested that a ceramic made of lanthanum phosphate would be a suitable replacement to the current matrices. Lanthanum phosphate is heat resistant up to 1000 Kelvin, a standard resistance for most temperatures. Past that, however, the mineral increases in plasticity. The more fluid-like state of the matrices prevents significant structural damage. After the reaction in the reactor, the matrices have a long time of relative low temperature to cool. During this time, the lanthanum phosphate ceramic retakes form and begins to repair the nuclear damage to its structure. According to Dr. Mecarthney, this can improve the overall process of generating nuclear energy as we know it.