Polarization Coupled Memristive Behavior in Oxide Heterostructures
Alexei Gruverman
Co-PI's: Alexander Sinitskii, Andrei Sokolov
The main objective of this proposal is to provide a basis for defining the strategic goals of a new Interdisciplinary Research Group (IRG) for the forthcoming MRSEC renewal, which will go beyond the topic of magnetoelectric studies of the current IRG2. By starting from studies of memristive switching in ferroelectric heterostructures, it has a potential to evolve into a much broader range of research topics that will constitute a core of new IRG: polarization-induced phase transitions and transport behavior at oxide and organic interfaces and will allow the MRSEC team to get at the forefront of the world-wide efforts on development of a new generation of functional oxide and organic devices. The new IRG will build upon an expertise in oxide materials synthesis and characterization enhanced by state-of-the-artlithography methods developed during the proposed research.
In this proposal, we seek to investigate the role of polarization in memristive effect - continuous tuning of resistivity by an electric field - in the ferroelectric films coupled with other transition-metal oxides and to explore the extent to which thin-film devices based on this effect could be developed.
The main thrusts of the proposed research can be summarized as follows:
(1) Investigation of the mechanism of memristive switching in ultrathin ferroelectric films
(2) Investigation of the effect of processing conditions on the memristive behavior in oxide epitaxial heterostructures;
(3) Fabrication of the prototype devices illustrating how complex oxides with tunable resistance can be used in microelectronics.
The assembled a team includes three co-PIs with mutually complementing expertise in oxidethin film growth by PLD (Sokolov, Physics), nanoscale functional characterization by SPM (Gruverman, Physics) and electronic device fabrication (Sinitskii, Chemistry). This synergetic combination of processing, characterization and device fabrication components emphasizes an interdisciplinary nature of the proposed research, which will reinforce existing and stimulate new collaborative research projects within the MRSEC.
Voltage dependence of the OFF/ON resistance ratio illustrating reversible nonvolatile memristive behavior in BaTiO3-based tunnel junction.
Example of two-terminal devices that will be fabricated in this project - crossbar structure that integrates multiple vertical devices.