The recent discovery of ferroelectric heterostructural alloys has realized a new pathway for ferroelectricity. Heterostructural alloys, alloys whose end compounds crystallize in different structures (such as MgO/ZnO or ScN/AlN) and produce a competition between ground state structure and local cation coordination environments. In rocksalt/wurtzite alloys, the compositionally driven phase competition and disorder destabilize the wurtzite structure thereby lowering the switching barrier of its intrinsic polarization. While promising, additional materials and design criteria for polarization size, coercive field, and depolarization thickness are needed for next generation electronics. Due to the complexity such unique alloys do not lie on the genome map of materials databases, and their ferroic properties may require intermediate alloy compositions that can only be realized with beyond-equilibrium growth conditions to prevent phase segregation. These factors have hindered the rapid realization of these new ferroelectrics.
Here, we consider alloy composition and disorder as design parameters that vastly expands phase space. We will leverage high-throughput theory predictions to rapidly map composition-structure-property space for new ferroelectric heterostructural oxide alloys. In conjunction with this theory effort, high-throughput combinatorial non-equilibrium thin-film growth and ferroelectric characterization will be used to rapidly evaluate composition-structure-property space and validate theoretical predictions.
Our goal is to develop a holistic understanding of the materials genome of stable and metastable complex oxides, including their local and global structure, thermodynamic stability, composition, and ferroelectric response.
Funding: $75K (2022)
Goal: The primary goal for this start project is to establish the high-throughput theory and experiment workflow and gain initial insights into the materials genome of stable and metastable ferroelectric heterostructural oxide alloys which will motivate external support.
Token Investors: John Heron, Wenhao Sun, Emmanouil Kioupakis, Robert Hovden, Rachel Goldman
Project ID: 1020