This experimental project is focused on the development of new artificially layered materials with engineered electrical and magnetic properties. With the state of the art deposition facilities in the PI's laboratory, the thickness of the stacked layers in the fabricated materials can be controlled on the atomic scale. The high perfection of the interfaces in these layered structures enables new interactions between the constituent materials to arise, and the result is novel behavior that could be the basis for improved performance in a number of crucial device applications, such as non-volatile computer memories, sensors, actuators and energy harvesters. A suite of cutting edge experimental tools, both in the PI's lab and at user facilities at Brookhaven National Laboratory are being used to probe the physics of the new materials, and build the required understanding for their optimization. The breadth of techniques utilized provides a long-term training benefit to the students carrying out the research. Tightly integrated with the research plan is an educational outreach program built around the development and dissemination of a set of unique and engaging teaching kits. Specific efforts are made to target diversity goals, largely by tapping into the extraordinarily diverse student community and existing educational outreach programs at Stony Brook University.
TECHNICAL DETAILS: Perovskite oxides are ideal "building blocks" for artificial materials because within relatively similar crystal structures they possess an extraordinary variety of complex structural distortions and associated functional properties. The key materials of interest in this project are either ferroic (ferroelectric, ferromagnetic, or ferroelastic) or multiferroic (exhibiting the combination of two or more ferroic properties in the same material). Recently there have been some astonishing examples in oxide materials in which behavior markedly different from bulk material properties is achieved by careful control of the interfaces. The central concept of the research is to use interfacial interactions, along with strain and electrostatics, to construct new ferroic materials with properties that are scientifically appealing and technologically useful. In practical terms, this involves the construction of fine period superlattices composed of titanate and manganite perovskite oxides using an off-axis RF magnetron sputtering technique. X-ray diffraction (both lab and synchrotron based), atomic force microscopy, transmission electron microscopy, and electrical techniques are then used to explore the fundamental physics of the artificial materials. Special emphasis is placed on phase transitions and phenomena related to domains. The wide variety of experimental techniques used in the project provides a team of graduate, undergraduate and high school students with hands-on experience with cutting-edge research techniques and facilities.
This grant is co-funded by the Office of International Science and Engineering (OISE)'s Europe and Eurasia Program.
