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The reflected electron spectroscopy was used to study Al/Nb interface. The Al/Nb interface was found to have an intermediate layer of about 10 nm thickness, which is more likely due to the interface roughness, rather than diffusion smearing.

Various x-ray diffraction experiments are employed to study the microscopic-scale structures of 0.72Pb([Mg.sub.1/3][Nb.sub.2/3])[O.sub.3]-0.28PbTi[O.sub.3] relaxor ferroelectrics in a high external dc field during phase transition. The results clearly prove that a change in the temperature also leads to a major change in the dominating cluster's orientation, as well as their interaction direction.

A study demonstrates that by carefully optimizing the reaction condition, it is possible to selectively fabricate niobate structures of high purity, including the delicate microporous fibers, through a direct reaction between concentrated NaOH solution and Nb2O6 units. Nioblates with different structures are found to exhibit remarkable differences in light absorption and photoluminescence properties.

The electronic structure of the hexagonal beta-Nb(sub 2)N, hexagonal delta-NbN and cubic delta-NbN thin films was investigated by X-ray photoemission spectroscopy. It was found that both beta-Nb(sub 2)N and delta-NbN are more covalent than the cubic phase NbN and covalent bonding in hexagonal beta-Nb(sub 2)N and delta-NbN nitrides can be related with the higher hardness values as compared to that of cubic phase.

The molecular and electronic structure of mixed valence d(super 1)d(super 2) (V, Nb, Ta) and d(super 4)d(super 5) (Fe, Ru, Os) face-shared [M2Cl9](super 2-) dimers is calculated by density functional methods in order to investigate metal-metal bonding in this series. General similarities are observed between d(super 1)d(super 2) and d(super 4)d(super 5) systems and can be considered to reflect the electron-hole equivalence of the individual d(super 1)-d(super 5) and d(super 2)-d(super 4) configurations.

Is this study it is seen that single-crystal PZN-PT exhibits a stretched exponential type relaxation in the time domain at room temperature. Further work needs to be done to clarify the relation between the polarization relaxation kinetics and differences in the domain structures to clarify the impact of kinetics on the fatigue process.

Various methods are applied for an extensive investigation of the physical properties of the Nb films and they are analyzed with respect to morphology and texture, stress and microstrain. The study shows that the growth stress and the microstrain, determined by the line profile analysis, can be correlated with the sharpness of the texture of the Nb films.

Discussing a quantitative study of the microstructure and critical current density of Nb-Ti superconductors that is produced with a varying combination of deformation intervals between anneals is presented. The TEM was used to quantitatively evaluate the degree of diffusional decomposition in a supersaturated solid solution at different stages of alloy statement.

The electronic structures of binary M21S8 (M = Nb, Zr) and isostructural ternary (M,M')(sub 21)S8 (M,M' = Hf, Ti; Nb, Ta) phases are analyzed by means of extended Huckel tight-binding band structure calculations. The distribution of hafnium and titanium atoms on the six crystallographically independent metal sites in the ternary phase Hf(sub 7.5)Ti(sub 13.5) are rationalized using metal-metal bond strength, electronegatavity/charge, and site volume arguments.

The magnetoresistance (MR) and thermal behaviors of the new magnetic tunnel junctions (MTJ) structures comprising CoNbZr layers are investigated. Thin CoNbZr films were used as an underlayer in order to get ultrasmooth interfaces for the bottom electrode, which was beneficial for reducing temperature-dependent TMR properties and by adjusting the bottom electrode thickness, TMR ratio of 32% was achieved.

Several studies are conducted to explain the mechanisms involved in the structural evolution of the Re (001) thin films grown that are grown on the Nb (110) surfaces via the molecular beam epitaxy technique. An increase in the Re thickness is shown to lead to the evolution of the surface morphology of the films.

The effects of rapid thermal annealing (RTA) on the electrical, optical, structural, interfacial and surface properties of Nb:Ti[O.sub.2] (NTO)-Ag-NTO multilayer electrodes inserting a nanoscale Ag layer for application in organic solar cells (OSCs) are examined. The studies have shown that the activation of Nb dopants in the top NTO layer has played a major role in the extraction of carriers from the organic layer to the anode (NTO-Ag-NTO) electrode.

The article explains the synthesis and the structural, dielectric and magnetic properties of the multiferroic [Ba.sub.4][Bi.sub.2][Fe.sub.2][Nb.sub.8][O.sub.30] compounds. The coupling behaviour exhibited by the compounds is also analyzed.

Several x-ray diffraction analyses are conducted to explain the microstructure, as well as the electrical properties of the Aurivillius phase ferroelectric solid solutions of [(Ca[Bi.sub.2][Nb.sub.2][O.sub,9]).sub.1-x][(Ba[Bi.sub.2][Nb.sub.2][O.sub.9]).sub.x] compounds. The relaxation behaviour exhibited by the compounds at high concentrations is also analyzed.

A study was conducted to examine the structural and magnetic properties of Fe-Nb-B amorphous/nanocrystalline alloys obtained by compaction of mechanically alloyed powders. Scanning electron microscopy images revealed that the presence of amorphous phase enhanced the quality of compaction.

A series of NbSr-doped lead zirconate titanate (PZT) materials with different Zr/Ti ratios over the whole range of the morphotropic phase boundary is prepared and sintered. The inverse behavior of remanent strain and field induced strain versus grain size has helped in deriving a description of the mechanisms that have governed the effects of grain size on strain.

The evolution of microstructure and mechanical properties of sputter-deposited Al/Nb multilayers with miscible fcc/bcc type interface and individual layer thickness (h), subjected to helium ion irradiations, is examined. The dependence of radiation hardening on h is inferred by using a composite model considering the formation of the hard [Nb.sub.3]Al intermetallic layer.

The Bridgman method is used for growing the large size Pb([In.sub.1/2][nb.sub.1/2])[O.sub.3]-Pb([Mg.sub.1/3][Nb.sub.2/3])[O.sub.3]-PbTi[O.sub.3] (PIN-PMN-PT) crystals directly from the melt. The enhanced field induced phase transition level has shown that the ternary PIN-PMN-PT crystals are promising candidates for high temperature and high drive transducer applications.

The carbonylation reaction of the dimethylniobium complex (BDI)[Me.sub.2]Nb([N.sup.t]Bu) (BDI = [beta]-diketiminate) is described. The results have shown an ability to dial in specific product mixture based on very subtle modifications to the reaction conditions, however the close proximity of diverse reaction pathways for second-row transition metals have impeded the progress in these areas.

The dielectric properties, microstructures and phase transition behaviors of [alpha] and [beta] phases of [Ca.sub.x][Ba.sub.1-x][Nb.sub.2][O.sub.6] ceramics with tungsten-bronze structure (TTB) are examined. A mechanism of partial melting and nucleation is described for explaining the grain growth behavior of TTB ceramic niobates.

The characteristics of the poling process of two samples of Er:LiNb[O.sub.3] grown by the Chzocralski technique is examined by comparing their optical properties. The results have that the erbium has caused a change of the coercive field value with respect to the pure congruent LiNb[O.sub.3] crystals and that the multidomain structure has affected the poling dynamics.

A dc magnetron sputtering technique is used to prepare a series of Nb nanogranular films with different grain sizes and thickness deposited on Si(100) wafer. The lattice parameters are found to be independent of thickness and grain size but are dependent on the oxygen contained in the grain boundaries.

The out-of-plane and in-plane x-ray diffractions are employed to explain the structural, as well as the dielectric characterizations of the relaxor/ferroelectric superlattice films Pb([Sc.sub.1/2][Nb.sub.1/2])[O.sub.3]/PbTi[O.sub.3], which are fabricated on a single-lattice scale. The superlattice structures of the films are shown to be coherent over the entire sample.

A study was conducted to examine the electrical properties of Nb-, V-, and W-doped [Bi.sub.4][Ti.sub.3][O.sub.12]-M[Bi.sub.4][O.sub.15] (BIT-MBTi) (M=Ca, Sr) compounds. The results provided insights into the remanent polarization (2[P.sub.r]) and piezoelectric coefficient ([d.sub.33]) of BIT-MBTi, which are greatly increased by donor doping.

The first principles calculation was conducted to determine the effects of composition and surface segregation on the electronic structures and related properties of the metal gate Nb-W system. The calculations provide insight into the tendency of Nb and W atoms to mix, instead of phase separate and the nonlinear effect of the interaction of Nb and W atoms on the electronic structures of Nb-W phases within the entire composition range.

Cubic potassium tantalite niobate [K[Ta.sub.1-x][Nb.sub.x][O.sub.3] (KTN)] crystals of large size, good quality and varying Nb concentration are grown by the Czochralski method and their thermal properties are studied. The results have shown that crystalline KTN is a very good material for optical applications.

The hybridization of the poly(anilines) (PANI) guest species incorporated within layered [K.sub.4][Nb.sub.6][O.sub.17] to form anisotropically oriented polyaniline/niobate (PANI/NbO) hybrids are reported. The hybrids are observed to exhibit efficient photoinduced redox reactions accompanied by reversible photochromic properties.

The structural and electrical properties of [Bi.sub.2][Mg.sub.2/3][Nb.sub.4/3][O.sub.7] films subjected to high temperature rapid thermal annealing (RTA) are examined for gate oxide application. It is shown that all annealed films have displayed high breakdown field values of more than 5 MV/cm.

The synthesis and characterization of volatile 1,1-dimethyl-2-(trimethylsilyl)hydrazido(1-) complexes of niobium, tantalum, molybdenum and tungsten are described. The hydrazine HN(Si[Me.sub.3])N[Me.sub.2](H-TDMH) is examined in order to find out if it is a suitable ligand for refractory metal precursor compounds.

The rectification of vortex motion on a Nb superconducting film with spacing-graded array of submicrometer-scaled holes is investigated. Findings indicate a drastic change of the vortex rectification for magnetic field above/below the first matching field.

The tracer diffusion coefficient for niobium in rutile Ti[O.sub.2] single crystals which could be applied to the processing of Nb-doped Ti[O.sub.2]-based semiconductors using solid-state reactions between [Nb.sub.2][O.sub.5] and Ti[O.sub.2] is reported.

The structural, electrical and optical properties of niobium doped Ti[O.sub.2] thin films grown on various substrates by pulsed laser deposition are studied. The epitaxial anatase Nb:Ti[O.sub.2] film on LaAl[O.sub.3] is shown as an intrinsic transparent metal, whereas the rutile Nb:Ti[O.sub.2] thin films have shown insulating behaviors with 2-3 orders higher room temperature electrical resistivity and 30 times lower mobility.

An efficient method is described for studying the mechanism of the electro-optic (EO) effect in perovskite-type ferroelectrics by using the electronic density-functional theory and the generalized gradient approximation. The results have shown that the EO effect in KNb[O.sub.3] and LiNb[O.sub.3] crystals have come from the relative displacements of the central metal ion and oxygen in the Nb[O.sub.6] oxygen octahedron induced by a low frequency applied electric field.

The synthesis and properties of a trimetallic compound[[[H.sub.3]O].sub.6][Fe[(CN).sub.6][(Mn(salen)].sub.6][Nb.sub.6][C.sub.12][(CN).sub.6]]*3[H.sub.2]O, which incorporates [[Fe[(CN).sub.6]].sup.4-], [[[Nb.sub.6][Cl.sub.12][(CN).sub.6]].sup.4-], and [[Mn(salen)].sup.+] as building units linked via cyanide ligands to form a superexpanded Prussian-blue analogue, are reported. This compound has represented the first successful attempt to incorporate mononuclear cyanometallate complexes and cyano-substituted octahedral metal clusters into the same framework.

Vibrating reed and superconducting quantum interference device magnetometer data have displayed prominent dips or oscillations of the superconducting (SC) onset temperature for an Nb/Ni multilayer (ML) in dc magnetic fields. It is shown that anomalies have marked dynamical instabilities within a confined, strongly anisotropic Abrikosov vortex lattice.

The synthesis, characterization and catalytic properties of mesoporous sulfated and phosphated Nb oxides is described and the catalytic activity in the benzylation of anisole is studied and compared to standard Nb phosphate and sulfate acid catalysts. The sulfated material showed the highest activity, which is attributed to the mesoporosity and increased concentration of Bronsted sites on the surface of the mesoporous channels.

The straightforward preparation and the crystal structure of the new compound [[Nb.sub.6][Cl.sup.i.sub.12][(CH3OH).sup.a.sub.4][Cl.sup.a.sub.2]].6C[H.sub.3]OH which contains the neutral [N[b.sub.6]C[l.sup.i.sub.12][(C[H.sub.3]OH).sup.a.sub.4]C[l.sup.a.sub.2]] cluster unit with an octahedral [[N[b.sub.6]C[l.sup.i.sub.12].sup.2+] cluster core is reported. The three-dimensional arrangement of the cluster units follows a stacking along the unit cell directions, resulting in a layered arrangement of the clusters, between which the methanol molecules are located.

A study describes how TT niobia-phase nanocrystals with controlled morphology were obtained by the hydrothermal treatment of a niobium peroxo complex precursor at very low temperatures. The materials obtained by this route present a very high surface area, ranging from 79 to 327 mg2/g, disordered Nb[O.cub.6], Nb[O.sub.7], and Nb[O.sub.8] polyhedra, Nb-O superficial sites, and a superficial OH group, which must have ensured the acidic characteristics of this oxide.

The complex dielectric permittivity studies of the [001]-oriented Pb(Mg1/3Nb2/3)O3 (PMN)-x% PT single crystal with the MPB composition is conducted as a function of temperature and poling field along [001]. The dielectric permittivity of the unpoled crystal exhibited two phase transition anomalies at [T.sub.T-R]~355 K and [T.sub.C-T]~424 K.

Cyclic voltammetry (CV) and atomic force microscopy (AFM) are used to determine fractal surface dimensions of sputter deposited niobium pentoxide films. AFM measurements showed that the former value corresponds to the fractal surface roughness of the films, while the latter value is close to the dimensionality of the distribution of hillocks on the surface.

The piezoelectric properties of {001} oriented 0.5Pb([Yb.sub.1/2][Nb.sub.1/2])[O.sub.3]-0.5PbTi[O.sub.3] films are analyzed. It is shown that the dynamic poling can affect the strain-ac electric field amplitude nonlinearity but not the charge-ac strain amplitude response.

A relaxor-to-normal, or micro-to-macrodomain, transition in Pb([Mg.sub.1/3][Nb.sub.2/3][O.sub.3])-xPbTi[O.sub.3], is found under electric fields applied along [001] for x>=0.24. The results have shown that an intermediate tetragonal ferroelectric phase is important to the sharpness of this transition, as observed in its dielectric response.

The waveguides in x-cut LiNb[O.sub.3] fabricated by 6.0 MeV [F.sup.3+] ion implantation with different doses are reported. The mode and loss patterns are analyzed and found that the waveguide structures fabricated by 6.0 MeV[F.sup.3+] ion implantation can be tailored for valuable usage based on an appropriate implanted dose.

A constitutive model that includes the effects of elasticity, crystal reorientation, phase transformations and plasticity is applied to a uranium- 6-wt% niobium (U-6Nb) alloy, which exhibits the shape memory effect. Computational simulations have demonstrated the ability of the model to capture the relevant physical response of the material.

The structural variations of undoped and [Cr.sub.2][O.sub.3]-doped [Sr.sub.0.5][Ba.sub.0.5][Nb.sub.2][O.sub.6] (SBN) are investigated along with the isothermal sintering behavior by using the x-ray diffractometer. The maximum dielectric constant ([epsilon.sub.max]) is determined by the competition between the reduction of the polarization due to the substitution of Cr for Nb and the enhancement of the polar moment arising from the weakening of Nb-O bonds due to the creation of the oxygen vacancies.

The synthesis and crystal and electronic structures of the Na(sub 2)(Sc(sub 4)Nb(sub 2))(Nb(sub 6)O(sub 12))(sub 3) niobium oxide whose structure is related to that of Ti(sub 2)Nb(sub 6)O(sub 12) is reported. Linear muffin-tin orbital calculations suggest that for Nb(sub 6)O(sub 12) framework the optimum valence electron count value is 14 and that reduction cannot be achieved.