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An in situ analysis of the tantalum thin films in an ultrahigh vacuum environment is used to observe the effects of oxygen on the thermomechanical behavior of such films, when they are under the beta-alpha phase transformation stage. The results demonstrate that the thermomechanical behavior is highly affected by the amount of oxygen, as well as the method of exposure to the film, as the phase transformation takes place by a nucleation and growth process that is limited by growth.

Describing the mechanism of the thick (Nb,Ta)3Sn layer synthesis, a simplified Ta-Sn powder core process, and a new Jelly Roll (JR) process using Sn-Ta sheet richer in Sn is investigated. The JR wires show attractive high-field performance at 22-23 T, and 5wt%Cu addition tot eh sheet effectively reduces the optimum heat treatment temperature.

Various analyses are conducted to explain the various different polar fluctuations taking place in the Mn substituted KTa[O.sub.3] ceramics. The results demonstrate that the generation of different electric dipoles in the system lead to the exhibition of a relaxor-type dielectric behavior by the ceramics.

Electron diffraction and high resolution x-ray diffraction are used for characterizing octahedral tilt transitions in epitaxial Ag[Ta.sub.0.5][Nb.sub.0.5][O.sub.3] (ATN) films grown on [(001).sub.p] (p = pseudocubic) oriented SrRu[O.sub.3]/LaAl[O.sub.3] and LaAl[O.sub.3] substrates. It is shown that point and planar defects in thin ATN films have disrupted the complex sequence of in-phase and antiphase rotations around [c.sub.p] thereby reducing the effective strength of interactions between the tilting and cation displacements.

The time and space resolved characterization of laser-generated pulsed plasmas is useful for the plasma generation and it has also permitted to control the nonequilibrium process that is useful for many applications. The characterization of the electron and ion energy distribution functions has correlated the ion properties, like charge states and temperatures, with the electron properties, like the shape of the EEDF at different times and distances from the ablated target surface.

First-principles study is used for analyzing the copper adhesion on Ta(110) and Ru(0001) surface with the density functional theory. The results have shown that Cu adsorbed on Ta(110) surface is desorbed and agglomerated on the top of the second Cu atom layer.

The effect of in-plane lattice strain on the atomic and electronic properties of low-index transition metal (M = Ti, Nb and Ta) carbide surfaces is analyzed by first-principles molecular dynamics calculations by using a pseudopotential plane-wave technique. The surface energy calculations have shown that surface stability is governed by the applied strain.

The behavior of the elastic precursor and its implication on the deformation mechanisms for tantalum are discussed. The tantalum has displayed strong rate sensitivity and the behavior is modeled through the low dislocation density and the strong stress dependence of the dislocation velocity.

The drift/diffusion model describing the effect of the transport and accumulation of copper ions on the time of failure of dielectrics is used for including metallic barriers and the effect of an elastic drift term. The change in the value of the field acceleration parameter is linked to many factors including the transport of oxidizing species through the barrier responsible for copper ion formation and the injection and motion of electrons and holes, which are changed in the presence of a barrier between the metal and dielectric.

The optical pyrometry technique is employed to determine the Hugoniot and melting temperatures of tantalum (Ta), as observed under the shock compression conditions. The analyses and the data are shown to be highly consistent and reliable.

Ultrahigh pressure and strain-rate reverberation experiments are performed in tantalum, aluminum, and copper to assess the yield strength behavior in this extreme regime. The experimental results revealed that the measurement sensitivity to yield strength is dominated by the lateral wave effects or impeded by the occurrence of spall.

TaCN layers are deposited by using metal-organic chemical-vapor deposition for applications as metal gate electrodes in p-type metal-oxide-semiconductor (pMOS) devices. The effective work function of the TaCN films is 4.8 eV on HfSi[O.sub.4] and HfSiON and is shifted weakly by high thermal budget annealing toward the Si valence band, reaching 4.9 eV on HfSi[O.sub.4].

A pulsed laser deposition technique is used to fabricate highly textured, stoichiometric, rocksalt TaN(111) films on Si(100). The studies have provided insight into the structure, the bonding, the stress, and the optical properties of highly textured polycrystalline [delta]-TaN films that exhibited fine structure due to the nonparabolic shape of the Ta 5d conduction band, originating from the crystal field splitting.

Ultrathin crystals of the layered transition-metal dichalcogenide Mo[S.sub.2] and Ta[S.sub.2] are produced by mechanical peeling or chemical exfoliation techniques and electrically contacted by employing electron-beam lithography. The Mo[S.sub.2] devices exhibited high field-effect mobility, whereas the Ta[S.sub.2] devices have remained metallic despite the fabrication process, showing an increase of the superconducting transition temperature and disappearance of the charge density wave phase anomaly at low temperature.