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Structure-Property Correlations of Vanadium OxideJagdish Narayan, North Carolina State University, DMR 0803663
Outcome: The researchers at North Carolina State University have integrated vanadium oxide, a material of immense technological importance for infrared sensors, on sapphire and silicon substrates for a variety of multifunctional devices.Impact: These thin film heterostructures create smart sensors and IR camera integrated with silicon microelectronics on a computer chip.
Explanation: Vanadium oxide has a very sharp semiconductor-metal transition in electrical and optical properties near room temperature, and has been shown to be ferromagnetic with Curie temperature above 2500C. With our invention of domain matching epitaxy, complex tetragonal and monoclinic structures of vanadium oxide can be grown as single crystals on sapphire and silicon substrates. By controlling defects in these single crystal films, we can tune the properties of these structures for a variety of smart magnetic and infrared sensors, needed for a myriad of military and homeland defense applications. Various current/potential applications
of VO2
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Single crystal thin films were deposited by pulsed laser deposition and Laser-MBE , pioneered by PI, on sapphire and silicon substrates using the paradigm of domain matching epitaxy. In this paradigm, this film epitaxy of complex tetragonal and monoclinc structures can be achieved by matching of integral multiples of lattice planes and systematic domain variation to accommodate any residual misfit. Part of Alok Gupta’s PhD thesis (who will be joining INTEL soon) focuses on integration of VO2 on sapphire and silicon through YSZ (yttria stabilized zirconia) and NiO (nickel oxide) buffer layers.
Integration with Silicon and Sapphire Substrates Jagdish Narayan, North Carolina State University, DMR 0803663
(a)(b)
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(a) Schematic of thin-film heterostructure c-Al2O3/NiO/VO2 (b) ɸ-scans confirming the epitaxial growth (c)/(d) Resistance/IR-transmission vs. temperature profile showing large resistive/IR-transmittance-switching behavior
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ion Educational Activities and Outreach
Jagdish Narayan, North Carolina State University, DMR 0803663
In less than three years, this program has graduated two very successfully employed PhDs, trained four undergraduates, and over a dozen papers in archival journals and equal number in conference proceedings, in addition to 2010 MRS Best Paper Award and several invited talks. Under PI’s leadership, NCSU launched M.S. degree course in Nanoengineering, where students from all over the world including minority (NCA&T and Shaw) institutions, can finish their degree, held very popular ASM Camp for high-school seniors, and transferred technology to Kopin Corporation. PI has also received 2011 Acta Materialia Gold Medal and Prize for his pioneering contributions and leadership in materials science worldwide.
The Materials Research Society Symposium on Frontiers in Thin Film Epitaxy and Nanostructured Materials (April 24-29, 2011, San Francisco) was dedicated to Professor Jay Narayan, The John Fan Family Distinguished Chair Professor, N C State University
http://www.mse.ncsu.edu/profile/narayan