Overview: Throughout human history, from Stone Age to Bronze Age to Iron Age to Semiconductors and Nanomaterials now, materials through their properties have played a critical role in improving the quality of human life and taking us to a next level. As an example, hardness played a key role in the Stone Age to sustain human life. Today, hardness plays a critical role in protective coatings for applications ranging from microelectronics packaging to cutting tools needed for oil and gas extraction and high-speed machining. Materials with hardness greater than 20GPa are defined as hard, those with hardness greater than 40 GPa are considered superhard, and those greater than 70 GPa are ultra-hard. Diamond with hardness 70-100 GPa is considered ultra-hard, while c-BN with hardness of 50 GPa is considered superhard. The hardness is a function of bulk modulus and Poisson������������������s ratio, while it increases with increasing bulk modulus and number density of atoms in covalently bonded materials like diamond, but it decreases with increasing Poisson������������������s ratio. Diamond is well established hardest material, because it has the highest bulk modulus and the number density of atoms along with low value of Poisson������������������s ratio. Therefore, our challenge in designing ultra-hard material is to enhance bulk modulus and number density of atoms, and keep Poisson������������������s ratio to a minimum. Intellectual Merit: This proposal is based upon a major materials breakthrough, where amorphous carbon and nanocrystalline h-BN can be converted directly into diamond and c-BN by nanosecond laser melting and quenching. By controlling the degree of undercooling, we have created novel Q-carbon and Q-BN phases, which exhibit 30 to 70% higher hardness than diamond. There is also evidence of three distinct phases of Q1, Q2 and Q3 and B-doped QB1, QB2, and QB3 with varying hardness. This polyamorphism in amorphous Q-phases is remarkably analogous to polymorphism in crystalline phases. We propose to investigate fundamental mechanisms of hardness enhancement in different coatings on model sapphire and steel substrates, and correlate with atomic structures. The enhanced toughness is derived from amorphous structure of Q-phases and composite nature of diamond nanocrystallites often embedded in Q-carbon matrix. The enhancement in adhesion is derived from laser melting and interfacial reactions to the substrate. We propose to create novel Q-carbon, Q-carbon and nanodiamond composites, Q-BN, and diamond/c-BN layered structures to achieve Holy Grail of enhanced hardness, toughness, adhesion and oxidation resistance in nanocomposite coatings. We will perform detailed atomic structure and bonding characterizations and correlate with hardness, toughness, adhesion and wear characteristics to evaluate the performance for cutting tool coatings. Our extensive laser-solid interaction simulation will guide the processing challenges and create novel materials with improved properties. Broader Impact: We propose to integrate this research with curriculum development and related educational activities, such as MS Nano program. The conversion of ordinary carbon into new phase of Q-carbon and diamond solves a key challenge in reducing carbon footprint and sustaining the quality of life. Since this conversion occurs at ambient temperatures and pressures, there is a significant reduction in energy usage and scale-up processing of diamond and related materials and their structures. The proposal addresses training of graduate and undergraduate students in collaboration with ORNL, Kopin Corporation and NC A&T to attract minority students into the graduate program. The PI initiated a very successful ASM Materials Summer Camp, where high-school students are trained for a week on new materials and technologies. We utilize our strong international exchange program for students and faculty. Under the PI������������������s leadership, NCSU has launched an MS degree in Nanoengineering through its Engineering Online network, where students around the globe can finish their MS degrees in Nanoengineering. As a part of this

This research program proposes a transformative approach to n- and p-doping of diamond and c-BN beyond the current state-of-the-art. The main concept is based on the recently discovered direct conversion of amorphous carbon into diamond and h-BN into c-BN at ambient temperatures and pressures in air in the form of large-area single-crystal films on substrates such as sapphire and silicon. The key advantage stems from the novel growth method, where the carbon layers are melted by using high-power nanosecond pulsed lasers in a highly super undercooled state, and then quenched rapidly either into a new state of carbon or into the single-crystal diamond phase in the presence of a template for diamond growth. Similarly, h-BN can be melted in a super undercooled state and converted into large-area single-crystal c-BN films. Accordingly, it is envisioned that dopant impurities present in the amorphous carbon and h-BN films can be incorporated into substitutional sites of diamond and c-BN during rapid liquid-phase crystallization via the phenomenon of solute trapping. As the proposed approach is a fundamentally nonequilibrium process, dopant concentrations in electrically active sites for both n- and p-types can far exceed the thermodynamic equilibrium solubility limits, while maintaining the energy levels, overcoming the long-standing challenge of diamond. Specifically, the feasibility studies on n-type doping (N, P, As and Sb dopants) will be carried out by incorporating these dopants into carbon by ion implantation, followed by rapid recrystallization from super undercooled state into epitaxial diamond thin film heterostructures. Similarly, n-type and p-type doping of c-BN will be achieved by Si and Zn dopants, respectively. The p-type (B dopants) doping of diamond will be accomplished by pulsed laser deposition of boron doped carbon layers at 500C in the presence of oxygen and hydrogen. Our preliminary results on nitrogen doping in diamond have already indicated that the dopant concentrations in electrically active substitutional sites can indeed be much beyond the thermodynamic solubility limits. Lattice location (substitutional versus interstitial) studies will be performed by using atomic resolution techniques and the results correlated with electrical activation and detailed carrier transport measurements. Theoretical calculations of dopant energy levels, ionization efficiencies, carrier concentrations and mobilities will be carried out in parallel to establish correlations with experimental results and to guide the fabrication of novel solid state devices. A primary goal of the combined effort is to demonstrate the p-n diodes of diamond and c-BN with satisfactory junction characteristics by controlling the dopant concentrations and the types vertically and/or laterally in the process. When successfully implemented, the proposed research is expected to revolutionize the doping and practical applications of diamond as well as the related materials such as c-BN.

Overview: We generate a lot of carbon through transportation, power generation and energy consumption. The reduction of carbon footprint in the US and the planet is the highest priority to sustain the quality of life for humankind. Since the graphite is the stable form of carbon, its conversion to diamond at ambient pressures and temperatures is against the equilibrium thermodynamics or the carbon phase diagram. According to the phase diagram it can be done only at very high pressures and temperatures (over 120,000Atm and 5000K). This proposal is based upon our recent discovery, where we showed that carbon can be converted directly into diamond at atmospheric pressure and ambient temperature in air. With the help of kinetics, we bypass thermodynamics and create new Q-carbon phase or diamond or a mixture of Q-carbon and diamond structures with exciting new properties. The primary focus of this proposal is to convert one of the most abundant materials into one of the most precious and useful materials in the form of Q-carbon and nanodiamonds across the scale for a variety of applications, ranging from diamond electronics and quantum computing to abrasives and coatings to biomedical devices Intellectual Merit: The primary objective of this proposal is to develop a fundamental understanding of basic mechanisms involved in the direct conversion of carbon into Q-carbon and/or diamond. The next step is to use this understanding to create novel diamond nanostructures with unique properties for a variety of applications. By using nanosecond pulsed laser irradiation, we propose to melt carbon in a super undercooled state at around 4000K (about 1000K below the melting point of carbon) and quench it into diamond or a new structure (distinct entropy), which is referred to as Q-carbon. This conversion into Q-carbon or diamond, which depends on the degree of undercooling will be investigated systematically as a function of laser and substrate parameters. The Q-carbon can also be converted into diamond by subsequent laser pulses. Atomic structure and bonding characteristics of Q-carbon will be studied and correlated with its unique properties, which include ferromagnetism with Curie temperature over 500K, extreme hardness (harder than diamond) and negative electron affinity. By controlling the nucleation and growth times, we can create novel nanostructures, ranging from nanodiamonds to large-area single-crystal films. The mechanism of formation of these single-crystal nanostructures will be investigated in detail, particularly their nucleation and growth characteristics and growth directions. The focus of this proposal is on synthesis and scale-up processing of pure and N-doped nanodiamonds (1-100nm of uniform size), microdiamonds (100-500nm) and microneedles (>2000nm) on crystalline sapphire and amorphous glass substrates, as needed for a variety of applications. This proposal expands our fundamental knowledge base on laser-solid interactions and transient thermal processing of materials, and on the critical role of structure, defects and chemistry in the properties of novel Q-carbon and diamond based nanostructures. Broader Impact: This discovery provides a very inexpensive and rapid way to convert carbon into useful diamond structures and harvest them conveniently for a variety of applications. Since this conversion occurs at ambient temperatures and pressures, there is a significant reduction in energy usage and scale-up processing of diamond and related materials and their structures. The proposed research will be integrated with four MSE graduate and undergraduate courses (MSE-760, 702, 465, 201 Honors) taught by the PI on Engineering Online Network. This proposal addresses training of graduate and undergraduate students in collaboration with ORNL, Kopin Corporation and NC A&T to attract minority students into the graduate program. The PI initiated a very successful ASM Materials Summer Camp, where high-school students are trained for a week on new materials and technologies. We propose to utilize our strong international exch

Abstract: This ARO staff research program will investigate the epitaxial growth and characterization of (La,Sr)MnO3, BiFeO3, BaTiO3, SrRuO3 and SrTiO3 films and heterostructures integrated epitaxially on Si (100) substrates. The goal is to conduct a detailed investigation of defect behavior and interface structure in these oxide systems, in order to determine how these factors influence the resultant electronic and magnetic properties of the films and the cross coupling of electrical and magnetic fields within these structures. The focus of the research will be on conducting a detailed nanoscale characterization (with sub-angstrom reso1ution) of the atomic structure and chemistry of the heterostructures using a probe corrected FEI Titan 60-300 S/TEM with a complement of spectroscopy attachments. The primary motivation for this research program is to identify experimental approaches for achieving robust electrical switching of magnetic moments in these complex oxide heterostructures.

Project Summary For next-generation solid state devices, integration for functionality and rapid response will require epitaxial growth of exciting sensor materials such as VO2 on Si (100), which is a preferred substrate of a computer chip. Interesting modification of electrical, optical and magnetic properties of VO2 in a controlled way can further enhance the functionality of such silicon based heterostructures. Intellectual Merit: In this proposal, the focus is on epitaxial VO2 thin film heterostructures functionally integrated with Si(100), which is a big challenge because of the complex VO2 structure and tendency to form interfacial amorphous SiO2. This problem will be solved by using t-YSZ, c-YSZ, NiO/TiN and TiO2/TiN buffer layers to create VO2/t-YSZ or c-YSZ/Si(100), VO2/NiO/TiN/Si(100), and VO2/TiO2 /t-YSZ or c-YSZ/Si(100) heterostructures. Using these buffer layers in epitaxial structures, we propose to control strains and formation of transient M2 phase and transition directly to M1 phase and optimize SMT characteristics needed for device applications. Growth of VO2 rutile phase in these heterostructures involved epitaxy across the misfit scale which was made possible by our paradigm of domain matching epitaxy. In the DME paradigm, integral multiples of planes match across the film-substrate interface with a systematic variation of domains to accommodate entire misfit during growth. We propose to investigate the details of epitaxy in the rutile phase (above the semiconductor to metal transition of 680C) and during the transition into the monoclinic phase, and correlate the residual strains with the transition characteristics. We have discovered ferromagnetism at room-temperature with Curie temperature above 500K in the VO2 thin films due to process-induced intrinsic defects. Our preliminary studies have also shown that magnetic, optical and electrical properties of these systems can be controlled by pulsed laser irradiation, swift heavy ion irradiation, and controlled vacuum annealing. In each case, certain defects are introduced with interesting parallels. We propose to identify these defects and correlate them with systematic changes in electrical, optical and magnetic properties. Our eventual goal is to write (using laser and ion beams) these properties in a controlled way for novel device applications (smart infrared sensors, novel magnetic sensors, nonvolatile memory devices). To enhance the responsivity of microbolometers for smart infrared sensors, the Si(100) in the proposed heterostructures will be in the form of thin membranes, which will be processed for test device structures. Broader Impact: This proposal impacts profoundly on smart multifunctional magnetic sensors and IR camera integrated with silicon microelectronics, and creates a fundamental knowledge base on thin film epitaxy in complex systems and on the critical role of defects and chemistry in the characteristics of ultrafast phase transition and electrical, optical and magnetic properties. The proposal addresses training of graduate and undergraduate students, and collaborations with ORNL and Kopin Corp technology transfer and NC A&T and Shaw University to attract minority students into the graduate program at NCSU. The outreach will also involve ASM-International sponsored Summer School for rising High-School seniors, which PI initiated at NCSU five years ago, and now it has become an annual event. These students are exposed to recent developments in new materials, analysis tools, materials properties and modeling. The PI has an excellent record of research collaboration and supervision of graduate and undergraduate students with NC A&T and Shaw (minority) Universities. Under PI?s leadership, NCSU has launched MS in Nanoengineering through Engineering Online network, where students around the globe can finish their MS. As a part of this program, PI teaches a series of courses which students from NC A&T and Shaw can learn latest developments in thin film epitaxy, defect control, processing, characterization and modeling (see attached

(1) This proposal is based upon our recent discovery of direct conversion of carbon into diamond or a new phase of Q-carbon at ambient temperature and pressure, where dopant concentrations can far exceed the Thermodynamic solubility limits. This novel nonequilibrium method will be used to create NV nanodiamonds, which are self-assembled and deterministically placed. These nanodiamonds will be epitaxially grown on (0001) sapphire substrate, so that all of them are exactly aligned with respect to each other. The size distribution and different placements for spin entanglement will be investigated systematically. (2) When molten carbon is quenched from a greater undercooling, we form a new phase of carbon, Q-carbon. This phase is ferromagnetic, when pure, but turns superconducting upon doping with boron. We have achieved highest BCS superconducting transition temperature of 57K at 25% at B concentration. By increasing the B concentration to 50 at%, we propose to achieve higher Tc. and explore interfaces of B-doped Q-carbon and topological insulators for Majorana Fermions.

SusChEM: Direct Conversion of Carbon into Diamond and Useful Micro and Nanostructures: Overview: We generate a lot of carbon through transportation, power generation and energy consumption. The reduction of carbon footprint in the US and the planet is the highest priority to sustain the quality of life for humankind. Since the graphite is the stable form of carbon, its conversion to diamond at ambient pressures and temperatures is against the equilibrium thermodynamics or the carbon phase diagram. According to the phase diagram it can be done only at very high pressures and temperatures (over 120,000Atm and 5000K). This proposal is based upon our recent discovery, where we showed that carbon can be converted directly into diamond at atmospheric pressure and ambient temperature in air. With the help of kinetics, we go over thermodynamics and create novel carbon based structures with exciting new properties. The primary focus of this proposal is on nanodiamonds, microdiamonds and microneedles for a variety of applications, ranging from abrasives to biomedical applications Intellectual Merit: The primary objective of this proposal is to develop a fundamental understanding of basic mechanisms involved in direct conversion of carbon into diamond. The next step is to use this understanding to create novel diamond structures with unique properties for a variety of applications. By using nanosecond pulsed laser irradiation, we are able melt carbon in a highly undercooled state at 4000K (over 1000K below the melting point of carbon) and quench it into a new structure (distinct entropy), which is referred to as Q-carbon. The diamond phase nucleates from the Q-carbon and by controlling the growth times, we can create the size ranges from nanodiamonds to microdiamonds. The formation of diamond single crystal microneedles will be investigated in detail, particularly their growth rates and growth directions. The undercooling needed to form the Q-carbon is a strong function of laser and substrate variables, which need to be controlled for various substrates. The Q-carbon has shown many exciting properties such as ferromagnetism with Curie temperature considerably higher than 300K. It has also shown enhanced field emission and very high hardness, both which will be investigated in detail and correlated with structure and bonding characteristics.. The focus of this proposal is on sapphire and glass substrates, from where diamond can be harvested, as needed for a variety of applications. This discovery provides a very inexpensive way to convert carbon into diamond and harvest it conveniently for a variety of applications. This proposal expands our fundamental knowledge base on laser-solid interactions and transient thermal processing of materials, and on the critical role of structure, defects and chemistry in the properties of novel Q-carbon and novel carbon based structures. Broader Impact: This proposal focuses on direct conversion of carbon into new state of carbon (Q-carbon) which has many exciting new properties, including ferromagnetism, super hardness and enhanced field emission. In addition, the diamond phase can be nucleated to form novel nanostructures and microneedles for a variety of biomedical applications. The conversion of ordinary carbon into new phase of Q-carbon and diamond, solves a key challenge in reducing carbon footprint and sustaining the quality of life. Since this conversion occurs at ambient temperatures and pressures, there is a significant reduction in energy usage and scale-up processing of diamond and related materials and their structures. The PI initiated a very successful ASM Materials Summer Camp, where high-school students are trained for a week on new materials and technologies. The proposal addresses training of graduate and undergraduate students in collaboration with ORNL, Kopin Corporation and NC A&T to attract minority students into the graduate program. We utilize our strong international exchange program for students and faculty. Under the PI������������������s leadership, NCSU has launched an MS degree in Nanoengineering through its Engineering Online network, where students around the globe can finish their MS degrees. As a part of this program, the PI teaches a series of courses through which students from NC A&T and Shaw can learn the latest developments in new materials, environmentally friendly materials processing, energy conservation during materials processingthin film epitaxy, defect control, processing, characterization and modeling (see attached interinstitutional agreement)

Topological insulators are an exciting new class of materials with very unique properties. We propose to fully exploit topological insulator based structures for unique advantages over conventional semiconductor counterparts in optoelectronic applications. In particular, the magnetoelectric interaction at the topological insulator-magnetic layer interface and subsequent possibility of band engineering in the momentum space is the focus of investigation as they can facilitate judiciously tailored response to an optical signal, offering an ideal environment for realizing previously unattainable performances such as extreme sensitivity detection at room temperature. In a combined theoretical and experimental effort, the objective of this research program is to design, fabricate, analyze, and demonstrate the envisioned hybrid structures/devices with superior optoelectronic characteristics on a silicon compatible platform.

Doping of Diamond beyond Thermodynamic Solubility Limit for Electronic Applications This research program proposes to exploit n- and p-doping of diamond based on the recently discovered direct conversion of amorphous carbon into diamond at ambient temperatures and pressures in air. The key advantage stems from the novel growth approach, where the carbon layers are melted by using high-power nanosecond pulsed lasers in a highly super undercooled state, and then quenched rapidly either into a new state of carbon (Q-carbon) or into the single-crystal diamond phase in the presence of a template for diamond growth. Accordingly, it is envisioned that dopant impurities present in the amorphous carbon films can be incorporated into substitutional (electrically active) sites of diamond during rapid liquid-phase crystallization via the phenomenon of solute trapping. As this is a fundamentally nonequilibrium process, dopant concentrations in electrically active sites for both n- and p-types can far exceed the thermodynamic equilibrium solubility limits, while maintaining the energy levels, overcoming the long-standing challenge of diamond. Feasibility studies on n-type doping (N, P or As dopants) and p-type doping (B dopants) will be carried out by incorporating these dopants into carbon by ion implantation, followed by diamond recrystallization. Lattice location (substitutional versus interstitial) studies will be done by using atomic resolution (STEM-Z) techniques and the results correlated with electrical activation and carrier transport measurements. In silicon, we have shown that this technique can be used to far exceed thermodynamic solubility limits via solute trapping. During solute trapping, dopants are buried against their chemical potential as result of strong barriers providing traps. When successfully implemented, the proposed research is expected to revolutionize the scale-up processing and practical applications of diamond as well as the related materials such as c-BN.

The proposed research will seek to correlate the structural properties of complex magnetic oxide films and heterojunctions with their magnetic and electrical properties. The oxides of interest are: ZnO dilute magnetic semiconductors (transition metal-doped), La-based manganate (half-metal), and BiFeO3 (a multiferroic). The research will address two major issues related to the epitaxial growth of magnetic oxides films. First, the research will continue studies to determine the mechanism for the ferromagnetism observed in transition-metal-doped ZnO (TM:ZnO). The second thrust will then focus on the epitaxial growth of (La,Sr)MnO3, BiFeO3 and TM:ZnO films on commercially ubiquitious sapphire (0001), Si(111) and Si(100) substrates, and investigate the formation of heterojunctions based on combinations of these oxides. This latter task will concentrate on the reduction of lattice-mismatch stress at heterojunctions and the reduction/passivation of defects (especially threading dislocations). This research program will emphasize detailed nanoscale characterization (with a reso1ution 0.16nm) of the atomic structure and chemistry of the heterostructures using JEOL-2010(GIF) atomic resolution TEM with STEM-Z and EELS attachments and then correlate these findings with the resulting electrical and magnetic properties of the films. Ultimately, the findings will be applied to the fabrication and characterization of test structures with field tunable properties.