CEMS Seminar Series - Dr. Julia Mundy
Dr. Julia Mundy, Assistant Professor, Department of Physics, Harvard University
Seminar title: "Design and construction of a new nickelate superconductor"
Abstract:
Since the discovery of high-temperature superconductivity in the copper oxide materials, there have been sustained efforts to both understand the origins of this phase and discover new cuprate-like superconducting materials. One prime materials platform has been the rare-earth nickelates and indeed superconductivity was recently discovered in the doped compound Nd0.8Sr0.2NiO2. Undoped NdNiO2 belongs to a series of layered square-planar nickelates with chemical formula Ndn+1NinO2n+2 and is known as the 'infinite-layer' (n=∞) nickelate. Here I will discuss how we can use oxide molecular-beam epitaxy to stabilize the full series of metastable Ndn+1NinO2n+2 compounds. In the n=5 member of this series, Nd6Ni5O12, in which optimal cuprate-like electron filling (d8.8) is achieved without chemical doping. We observe a superconducting transition beginning at ∼13 K. Electronic structure calculations, in tandem with magnetoresistive and spectroscopic measurements, suggest that Nd6Ni5O12 interpolates between cuprate-like and infinite-layer nickelate-like behavior. In engineering a distinct superconducting nickelate, we identify the square-planar nickelates as a new family of superconductors which can be tuned via both doping and dimensionality.
Julia Mundy is an assistant professor in the Department of Physics at Harvard University. She received an AB/AM in Chemistry and Physics from Harvard University and her Ph.D. in Applied Physics from Cornell University. Following her Ph.D. studies, she spent a year at the US Department of Education as the APS/AIP STEM Education Fellow. After a postdoctoral fellowship at UC Berkeley, she returned to Harvard University where she began as an assistant professor in 2018. Prof. Mundy's research program combines atomically-precise oxide molecular-beam epitaxy with picoscale electron microscopy imaging to design, synthesize and probe new quantum materials. She is a recipient of the 2018 APS George E. Valley, Jr. Prize, the 2019 IUPAP Young Scientist award in the field of magnetism, 2020 Packard Fellowship and is a Moore Fellow in Materials Synthesis.
