In today's rapidly changing world, there is constant demand for the development of new, high performance materials. Fire resistant steels can provide greater safety in the event of a building fire, creep resistant stainless steels can allow for higher power plant efficiency, and cobalt based superalloys have potential for use...
Graphene offers promising opportunities for applications in printed and flexible electronic devices due to its high electrical and thermal conductivity, mechanical flexibility and strength, and chemical and environmental stability. However, scalable production and processing of graphene presents a critical technological challenge preventing the application of graphene for flexible electronic interconnects,...
The transport properties of mayenite-based materials, Ca12Al14O33, were investigated. Systems studied included H-doped/ UV-irradiated Ca12Al14O33, Ca(12-x)MgxAl14O33 (x = 0.1, 0.3, 0.5, 0.8, 1) and Ca12Al(14-x)SixO(33+x/2) (x = 1, 2, 3, 4). The as-prepared Ca12Al14O33 exhibited a room temperature electronic conductivity on the order of 10^-10 S/cm, and a high temperature...
The electronic transport and magnetoresistive properties of the ferromagnetic semiconductor In1-xMnxAs were investigated in order to determine the nature of the transport and ferromagnetism in the films. p-InMnAs/n-InAs and metal/oxide/InMnAs heterojunctions were fabricated and characterized to elucidate the transport and magnetoresistance mechanisms at these technologically important interfaces.
The electronic transport...
Biomorphic silicon carbide (bioSiC) is a novel porous ceramic material derived directly from wood precursors. This material is fabricated by pyrolysis of a natural wood precursor in an inert atmosphere leaving an amorphous carbon scaffold. The amorphous carbon is infiltrated with molten Si in vacuum at elevated temperature, which reacts...
Solid oxide fuel cells (SOFCs), renowned for their high electrical generation efficiency with low pollutant production, are promising for reducing global energy and environmental concerns. However, there are major barriers for SOFC commercialization. A primary challenge is reducing the capital cost of SOFC power plants to levels that can compete...
Fundamental investigations on the origins of friction at the nanoscale were carried out using both theoretical and experimental approaches. A model was developed that analytically solves for friction by the motion of dislocations at atomically flat crystalline interfaces. It combines known concepts from dislocation drag, grain boundary theory, and contact...
The optical and magneto-optical properties of the ferromagnetic semiconductors, InMnAs and its alloy InMnAsP were investigated to determine the band structure and nature of the ferromagnetism in these materials. Alloys were grown by metal-organic vapor phase epitaxy. Infrared absorption of InMnAs was investigated to determine the presence and properties of...
Ceramic matrix composites are known for their low density, high strength and high stiffness, but lower fracture toughness compared to metal matrix composites. The addition of a reinforcing agent within the matrix can increase the toughness of the composite via many strain energy absorption mechanisms such as plastic deformation. This...
Using ab initio calculations, we discovered a quasi two-dimensional copper–bismuth nano sheet, which we call cubine. According to our predictions, single layers of cubine can be isolated from the recently reported high-pressure CuBi bulk material at an extremely low energetic cost, comparable to values to separate single layers of graphene...