Science at the Edge Seminar
Speaker: Jay Narayan, Department of Materials Science and Engineering, North Carolina State University
Title: Novel Q-Materials by Nonequilibrium Activation for Next-Generation Solid State Devices
Refreshments at 11:15 am.
Date: Fri, 20 Apr 2018, 11:30 am – 12:30 pm
Location: 1400 BPS Bldg.
Throughout human history, materials have have played a critical role in advancing revolutionary technologies which have benefitted society. From Stone Age to Bronze Age to Iron Age to Semiconductors and now novel nanomaterials, materials through their properties have played a critical role in improving the quality of human life and taking us to a next level. Recent discovery of Q-Materials may take us to a higher level yet in view of their unprecedented superior properties. Discoveries related to Q-carbon and Q-BN, and direct conversion of carbon into diamond and h-BN into c-BN at ambient temperature and pressure illustrate power of nonequilibrium activation and processing. Among its many unique and unprecedented properties, Q-carbon is harder (as much as 70%) than diamond, it is ferromagnetic in pure form and it can be made superconducting upon doping with boron with transition temperature over 57K (highest for BCS superconductors). This record superconducting temperature is expected to go still higher with increasing B-concentration in Q-carbon. Carbon can be also converted into diamond in the form of single-crystal nanodots (NV nanodiamonds), microdots, nanoneedles, microneedles, and large-area single-crystal films, which can be doped with both n- and p-type dopants. Doping of diamond with n-type dopants with concentrations far higher than solubility limits is made possible only by nonequilibrium laser processing. This breakthrough has a potential to create next-generation high-power, high-frequency, high-temperature, and radiation-resistant devices for a variety of applications. To realize the full potential of these Q-carbon and diamond related materials and structures, they need to be integrated on practical substrates through the paradigm of domain matching epitaxy to achieve much needed functionalities in novel solid-state devices. All these aspects will be covered in this colloquium.