Claribel obtains the iWOE26 poster prize

Claribel Dominguez, currently working on the exciting field of “oxide interface physics”, received the iWOE26 poster prize for her research “Engineering electronic coupling of metal-insulator phases at SmNiO3/NdNiO3 interfaces”.

Nowadays, interfaces between different compounds are a recognized playground to manipulate the electronic phases of transition metal oxides. In the last years, control of the structural coupling of the oxygen sublattices during epitaxy synthesis is arising as a very powerful strategy to manipulate the states of matter in complex oxides.

“In order to get further inside into this topic, explains Claribel, as a model system we take SmNiO3 and NdNiO3 from the fascinating rare earth nickelate family RNiO3, well-known for their sharp metal-to-insulator transition (MIT) observed as a function of temperature. In bulk form, these two compounds show a MIT at two very different temperatures (400K and 200K, respectively). We create atomic-precision epitaxial superlattices that display, depending on the thickness of the individual layers, a single or double MIT. These heterostructures allows the origin of the coupling at such oxide interfaces to be studied. The key finding is that the length scale of the metal-insulator transition is not set by the length scale of the propagation of structural motifs (for instance Ni-O-Ni bond angles) across the interface between the two materials, which ab-initio calculations and TEM analyses suggest is minimal, but rather by the balance between the energy cost of having metallic-insulating phase boundaries and the bulk energetics. This result opens a new path for engineering functional properties in heterostructures that are not available in bulk. This represents a paradigm-shift in our understanding of oxide interfaces.”