Generation of long time creep data of refractory alloys at elevated temperatures Eleventh quarterly report, 26 Dec. 1965 - 26 Mar. 1966

Creep tests of arc-cast and vapor deposited tungsten, molybdenum alloys, niobium, and tantalum base alloys for use in advanced power system

Generation of long time creep data on refractory alloys at elevated temperatures Quarterly report, 26 Oct. - 26 Dec. 1966

Long-time creep data on refractory metal alloys for advanced space power system

Generation of long time creep data on refractory alloys at elevated temperatures eighth quarterly report

Creep resistance of refractory alloys at elevated temperatures under ultrahigh vacuum condition

Elevated temperature fatigue of TZC MOLYBDENUM alloy under high frequency and high vacuum conditions

Elevated temperature fatigue of TZC molybdenum alloy determined in high frequency and high vacuum test

Magnetic phase transition in V2O3 nanocrystals

V2O3 nanocrystals can be synthesized through hydrothermal reduction of VO(OH)2 using hydrazine as a reducing agent. Addition of different ligands to the reaction produces nanoparticles, nanorods and nanoplatelets of different sizes. Small nanoparticles synthesized in this manner show suppression of the magnetic phase transition to lower temperatures. Using muon spin relaxation spectroscopy and synchrotron x-ray diffraction, it is determined that the volume fraction of the high-temperature phase, characterized by a rhombohedral structure and paramagnetism, gradually declines with decreasing temperature, in contrast to the sharp transition observed in bulk V2O3.Comment: 6 pages, 6 figure

Determination of the structure and geometry of N-heterocyclic carbenes on Au(111) using high-resolution spectroscopy

N-heterocyclic carbenes (NHCs) bind very strongly to transition metals due to their unique electronic structure featuring a divalent carbon atom with a lone pair in a highly directional sp(2)-hybridized orbital. As such, they can be assembled into monolayers on metal surfaces that have enhanced stability compared to their thiol-based counterparts. The utility of NHCs to form such robust self-assembled monolayers (SAMs) was only recently recognized and many fundamental questions remain. Here we investigate the structure and geometry of a series of NHCs on Au(111) using high-resolution X-ray photoelectron spectroscopy and density functional theory calculations. We find that the N-substituents on the NHC ring strongly affect the molecule-metal interaction and steer the orientation of molecules in the surface layer. In contrast to previous reports, our experimental and theoretical results provide unequivocal evidence that NHCs with N-methyl substituents bind to undercoordinated adatoms to form flat-lying complexes. In these SAMs, the donor-acceptor interaction between the NHC lone pair and the undercoordinated Au adatom is primarily responsible for the strong bonding of the molecules to the surface. NHCs with bulkier N-substituents prevent the formation of such complexes by forcing the molecules into an upright orientation. Our work provides unique insights into the bonding and geometry of NHC monolayers; more generally, it charts a clear path to manipulating the interaction between NHCs and metal surfaces using traditional coordination chemistry synthetic strategies