Materials that undergo sharp transitions in their conductivity upon external stimulus represent an emerging class of semiconductors. These materials could affect future computing technologies and opto-electronic devices. Understanding the microscopic nature of the transitions is important to model their behavior. In this project, the PIs will collaboratively explore the role of atomic scale defects introduced by doping in controlling the conductivity and how it varies spatially within the material. This will be accomplished by combination of high-spatial resolution scanning probe microscopy that is sensitive to conductivity at the nanoscale and theoretical modeling of electrical conduction in the sample containing varying concentrations of such defects. In addition to research, the PIs will participate in educational and outreach activities including engaging high school students from diverse backgrounds in the Atlanta area to participate in physics research.
Perovskite nickelates undergo insulator-metal transitions that can be modulated by external stimuli such as temperature, pressure as well as growth protocols. Microscopic understanding of the phase transition with emphasis on scanning probe techniques will be accomplished by using integrated high-resolution experimental nanoscale near-field imaging and spectroscopy techniques covering infrared to THz, theoretical calculations and Monte Carlo Simulations. The research will impact electronic and optical materials engineering and devices, fundamental physics, and materials science. The results will enable fundamental quantitative understanding of the first order phase transition of correlated oxides at high-spatial resolution and will have a significant impact on future electronics and photonics, sensing, neuromorphic devices. The research and integrated education plan will promote undergraduate and graduate materials and nano-optoelectronic education in the Athens/Atlanta area. The work throughout this research will provide participating students, including those from underrepresented groups, with advanced multidisciplinary skills to tackle challenging condensed matter/materials physics problems. The project will include development of new courses, undergraduate research and advising and provide travel fellowships for students from other institutions to attend Workshops. The PIs will integrate research into outreach activities for high school physics teacher(s)/students' education and training as well as community outreach that targets African immigrant students/families and African American youth in the Athens/Atlanta area.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
