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The interface resistance in Ni/Nb multilayers prepared by sputtering system is analyzed. The current perpendicular to plane (CPP) measurement interpreted with a one-band series-resistor model is used for obtaining the CPP resistivities of Nb and Ni and the unit area resistances for superconducting and normal Ni/Nb interfaces.

Polycrystalline samples of [Ru.sub.1-x][Nb.sub.x][Sr.sub.2][Eu.sub.1.4][Ce.sub.0.6][Cu.sub.2][O.sub.10-[delta]] are prepared by conventional solid state reaction by using stoichiometric amounts of high purity Ru[O.sub.2], [Nb.sub.2][O.sub.5], SrC[O.sub.3], [Eu.sub.2][O.sub.3], Ce[O.sub.2] and CuO powders. The critical temperatures, including the onset, intergrain and intragrain transition and [T.sub.R=0] transition temperatures, have depended on the Nb content, microstructure and applied magnetic field.

The simplified vibrating sample magnetometer is fabricated and the trapped magnetic flux in Nb superconducting thin film is measured by vibrating sample near the search coil. Many vortices are trapped in the perimeter of the sample when a perpendicular magnetic field is applied and the studies have confirmed that Josephson current is modulated by the parallel magnetic field generated by the vortices.

The intercomparison of the superconductivity of Mg[B.sub.2], Al[B.sub.2], Nb[B.sub.2+x] is presented. The nonstoichiometry has induced an increase in c parameter with Boron excess both in Nb[B.sub.2+x] and Ta[B.sub.2+x] and magnetization and resistivity measurements in case of niobium boride samples have shown the absence of superconductivity in stoichiometric Nb[B.sub.2] sample.

(1-x)([Bi.sub.0.9][La.sub.0.1])Fe[O.sub.3]-xPb([Fe.sub.0.5][Nb.sub.0.5])[O.sub.3] (BLFO-PFNO) are examined as an A-site substituted counterpart multiferroic solid solution. The BLFO-PFNO solid solution system has enabled soft ferromagnetism at room temperature and macroscopic polarization with the ferroelectric domain evolution due to nanoscale ordered single grains at high composition of relaxor-type ferroelectric PFNO.

The traditional solid state reaction method is used for preparing perovskite solid solution ceramics and ferroelectric and dielectric measurements have shown that these samples are relaxor type ferroelectric materials. The ac susceptibility measurement has showed that the peak position is dependent on frequency, thus indicating a glassy or relaxor type behavior and describing the 0.9Pb([Fe.sub.0.5][Nb.sub.0.5])[O.sub.3]-0.1PbTi[O.sub.3] to be a magnetoelectric relaxor material.

The current-voltage characteristics and magnetotransport properties of [La.sub.0.7][Sr.sub.0.3]Mn[O.sub.3]/Nb(1.0%):SrTi[O.sub.3] junctions under various currents and different temperatures ranges are examined. The resistance, magnetoresistance and electroresistance of the junctions are dependent on bias-current direction, current, magnetic field and temperature.

Magnetic properties and microstructure of directly quenched [Nd.sub.9.5][Fe.sub.72.5][Ti.sub.3-x][M.sub.x][B.sub.15] (M=Nb and Zr) bulk magnets in rod form with a diameter of 0.9 mm are analyzed. Proper Nb or Zr substitution for Ti has modified phase constitution and has refined the grain size effectively and their high permanent magnetic property has occurred from the existence of a large volume fraction of 2:14:1 phase, finer grain size and the existence of grain boundary phase.

The phase evolution, microstructure, and magnetic properties of melt spun Sm[Co.sub.7-x][Nb.sub.x] (x = 0-0.6) ribbons are examined by using powder, x-ray diffraction, transmission electron microscopy and vibrating sample magnetometer. The mechanism of the coercivity enhancement is discussed along with its optical magnetic properties.

A strong magnetoelectric (ME) interaction is described in a magnetostrictive-semiconductor-piezoelectric heterostructure consisting of the Huesler alloy, [Co.sub.2]MnAl, GaAs, and lead magnesium niobate-lead titanate (PMN-PT). A large ME coupling is obtained and static magnetization measurement has shown a reduction in the remanence magnetization while applying the electric field, which has corroborated the ME interactions mediated by the translation of magnetoelastic forces in this structure.

The temperature stability of field induced uniaxial anisotropy ([K.sub.U]) is examined by thermomagnetic treatments of [([Co.sub.1-x][Fe.sub.x]).sub.89][Zr.sub.7][B.sub.4] amorphous ribbons after field annealing below and the above the crystallization temperature. Field crystallization is required for elevated temperature applications when field induced anisotropy is vital for performance.

The field-induced magnetic anisotropy ([K.sub.u]) and the hyperfine interactions in nanocrystalline [Fe.sub.94-x][Nb.sub.6][B.sub.x] alloys are examined with respect to the origin of [K.sub.u] in the bcc-Fe/amorphous soft magnetic nanostructures. The relatively large [K.sub.u] value estimated for the bcc nanocrystallites is attributed to a possible local tetragonal distortion induced by the interstitial B atoms.

The power supply efficiency can be improved by using the glassy metal alloy [Fe.sub.77][P.sub.7][B.sub.13][Nb.sub.3] powder in an inductor core. The heat generation in the core is suppressed by using the low loss power and it has become easy to design a temperature rise in the entire power supply circuit.

The effect of [B.sub.2][O.sub.3] flux melting on the soft magnetic properties of [([Fe.sub.0.75][B.sub.0.20][Si.sub.0.05]).sub.96][Nb.sub.4] bulk metallic glass prepared by casting is examined. The results have shown that it is possible to develop a new soft magnetic material that has displayed constant permeability with low core loss.

Exchange bias phenomena of nanocrystalline FeCuNbSiB ribbons are examined at room temperature. The topography of ribbon surfaces and the configuration of magnetic domains are observed in order to make clear the dependence of bias behavior on the induced magnetic anisotropy.

The modification of BiFe[O.sub.3] multiferroic ceramics are examined by introducing NaNb[O.sub.3] to form ([Bi.sub.1-x][Na.sub.x])([Fe.sub.1-x][Nb.sub.x])[O.sub.3] solid solutions. Weak ferromagnetism with remnant magnetization of 0.14 emu/g and coercive field of 6.48 kOe are observed, indicating that the modified ceramics have enhanced multiferroic characteristics.

Conventional solid-state reaction method is used for producing ([K.sub.x][Na.sub.0.96-x][Li.sub.0.04])([Nb.sub.0.85][Ta.sub.0.15])[O.sub.3] piezoelectric ceramics and the effects of K/Na ratio on the phase transitional behavior, Raman spectrum and dielectric, piezoelectric and ferroelectric properties are examined. The results have shown that the equal K/Na ratio is not the only condition required for obtaining optimized electrical properties in ([K.sub.x][Na.sub.0.96-x][Li.sub.0.04])([Nb.sub.0.85][Ta.sub.0.15])[O.sub.3] ceramics.

Shifted hysteresis loops characteristic of the exchange bias effect between a ferromagnet and an antiferromagnet are shown in structures formed by Cr layer deposited on top of an array of Fe nanoislands (Cr/Fe-nanoislands). The comparative study between superconducting proximity effects in Nb/Cr/Fe-nanoislands and Nb/normal metal/Fe-nanoisland hybrids has confirmed the presence of antiferromagentic order in the Cr spacer layer.

The perovskite oxynitrides EuM[O.sub.2]N (M = Nb, Ta) are prepared and their coupled colossal magneto-resistive and capacitive effects are studied. The results have shown an excellent potential for large magneto-responses in materials like EuNb[O.sub.2]N, which has combined the large [Eu.sup.2+] spin and the off-center instability of [Nb.sup.5+] enhanced by bonding to nitride.

Broad and frequency dependent maxima observed in both the electric and magnetic susceptibilities for 0.3Pb([Fe.sub.1/2][Nb.sub.1/2])[O.sub.3]-0.7Pb([Mg.sub.1/2][W.sub.1/2])[O.sub.3] solid solution, magnetic and electric relaxor is reported. The magnetoelectric coupling in system is found to be negligibly small in spite of its multiferroic properties.

NbN films are deposited by using direct current reactive magnetron sputtering in discharge of a mixture of [N.sub.2] and Ar gas and the effects of substrate bias ([V.sub.b]) on the preferred orientation, phase transition and mechanical properties for NbN films are studied by x-ray diffraction. The results have shown that [V.sub.b] has a major impact on the stress in NbN films, which has led to a pronounced change in the preferred orientation, phase structure and hardness.

Ab initio calculations have helped in constructing an n-body Fe-Nb embedded-atom potential and are used for studying the crystal-to-amorphous phase transition through molecular dynamic simulations. The formation mechanism of the metastable phases and the fractal pattern observed in the Fe-Nb system are discussed in terms of the atomic collision theory and the well-known cluster-diffusion-limited-aggregation model.

A longitudinally magnetized-transversely polarized (L-T) mode magnetoelectric (ME) laminate composite is developed by sandwiching a special-oriented piezoelectric 0.7Pb([Mg.sub.1/3][Nb.sub.2/3])[O.sub.3]-0.3PbTi[O.sub.3] (PMN-PT) single crystal between two longitudinally magnetized magnetostrictive Terfenol-D plates. The studies have revealed a new method for enhancing the ME effect of the ME composite.

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.

A weak, highly anisotropic spin-sensitive order in dilutely magnetically doped Nb[Se.sub.2] is described along with the demonstration of modification of that ordering by the onset of the charge density wave (CDW) transition. Qualitative and quantitative charges observed below 20 K in reflectance spectra are shown to be optical signature of the dramatic changes in quasiparticles scattering at such temperatures.

The magnetic and transport properties of variable-thickness bridges (VTBs) having Nb/[Pd.sub.0.85][Ni.sub.0.15] bilayer microbridges are examined. The studies have shown that the superconducting critical current of the VTBs has monotonically decreased with increasing PdNi thickness [d.sub.F], while the nonmonotonic behavior of the superconducting transition temperature is seen as a function of [d.sub.F] in large Nb/PdNi bilayer films.

Electron-beam lithography and reaction dry etching methods are used for fabricating superconductor thin films with regular square hole arrays to explore the vortex pinning behavior. Novel pinning phenomenon is found in the magnetoresistance measurements of all the samples and it is related to the multivortex states.

Two-dimensional magnetic field dependence of various shaped Josephson junctions is analyzed. The two-dimensional magnetic field dependence of a Josephson junction is simulated by calculating the superconducting current density distribution in each magnetic field.

The superconducting properties of sputtered multilayers of Nb/Pd/Fe are studied. The structural, superconducting and magnetic behavior analyses in samples with varying thickness have showed that the Pd spacer removes the alloying between Nb and Fe, thus paving the way for the occurrence of reentrant superconducting effects in this system.

The evolution of the magnetic domain structure with the applied torsion is analyzed by using the Bitter method on high magnetostrictive [Fe.sub.73.5][Si.sub.13.5][B.sub.9][Nb.sub.3][Cu.sub.1] amorphous wires. A correlation between coercivity and reduced remanence with the applied torsional strain is studied.

A Cu-oxide layer prepared on the surface of FeSiBNbCu nanocrystalline alloy powder and then the FeSiBNbCu nanocrystalline alloy powder cores are prepared by compaction at room temperature. The characteristics of the Cu-oxide layer and its effect on the high frequency magnetic properties of the compacted cores are examined.

The crystal structure, magnetic structure and magnetic properties of RE-Fe-B (RE-rare earth) films prepared on an Nb buffer layer on thermally oxidized Si substrates are analyzed. The results have shown that after annealing, the c-axis texture and perpendicular anisotropy of RE-Fe-B films have increased strongly with the increase of deposition temperature.

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 impact of Al substitution on crystal structure and magnetic properties of [Nd.sub.3][Fe.sub.27.5-x][Ti.sub.1.5][Al.sub.x] compounds is determined using x-ray diffractions, time-of-flight powder neutron diffraction, and magnetic measurements. The findings suggested that the Curie temperature rises monotonously with increase in Al content and the magnetization reduces almost linearly.

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 vortex propagation in Nb superconductors with one dimension spacing-density of submicrometer-scaled holes is investigated. The results have shown that the rectification effect is characterized by the asymmetric pinning landscape and the rectified voltage has depended on temperature and the amplitude of applied ac.

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.

The microwave absorption and characteristic impedance changes of integrated CoNbZr magnetic films on coplanar waveguides (CPW) as a function of film thickness, is systematically investigated. The results show that as the thickness of the integrated magnetic films on the CPW increased, the characteristic impedances slightly increased up to 10 ohms in comparison to that of the CCPW.

Carrier induced ferromagnetism in Nb and transition metal codoped anatase [Ti.sub.1-x-y][Nb.sub.x][M.sub.y][O.sub.2] (M=Co, Fe) epitaxial films grown by pulsed laser deposition method was investigated. The results of the investigation reveal that the charge carriers are spin polarized and mediate ferromagnetic interaction between local spins on transition metal ions.

The glass-forming ability and magnetic properties of (Fe, Co)-B-Si-Nb glassy alloys is investigated. The maximum diameter for the formation of a glassy alloy rod is 2.0 mm for Fe72B20Si4Nb4 and 4.0 mm for (Fe0.5Co0.5)72B20Si4Nb4.

The elimination of magnetic closure domains in a micropatterned film is discussed to have the desired loss generation profile against the operating frequency. A demonstration of the rf loss generation profile over a thin-film coplanar transmission line, using micropatterned films with various slit designs is presented.

Complex permeability spectra of CoNbZr thin films are measured up to 4 GHz by a single coil pertubation technique. In addition to the well-known ferromagnetic resonance, multiple resonant modes are evidenced in the increasing branches of the spectra.

A double-barrier magnetic tunnel junction (DMTJ) comprising an amorphous freelayer is investigated. Ultrathin amorphous magnetic CoZrNb is introduced into the freelayer of a DMTJ to improve the magnetic and transport properties with an emphasis given on the bias voltage dependence.

Paramagnetic properties of binuclear niobium complexes Nb-O-Nb with two nonequivalent Nb(super 4 +) ions in lithium-niobium phosphate glasses are investigated. Experimental electron paramagnetic resonance spectrum analysis revealed nonequivalent distribution of the charge and electron spin density between two Nb atoms.

The effect of parallel ferromagnetic domain structure in Nb/SrRuO3 on the critical current of Nb with current flowing perpendicularly to the domains is studied. It is shown that in this configuration the superconducting critical current decreases, suggesting lower vortex pinning.

The fabrication of highly transparent superconductor/normal metal/ two-dimensional electron gas junctions formed by a superconducting NbN electrode, a thin (10 nm) Au interlayer, and a two-dimensional electron gas in an InGaAs/InP heterostructure is reported. The findings show that the reduced subgap resistance remains in high magnetic fields and zero-field data are analyzed within the previously established quasiclassical model for the proximity effect.

The effect of substitution on the structure and temperature dependence of magnetic properties of intrinsic and substituted strontium ferrite particles is investigated. It is shown that Zn and Nb substituted strontium hexaferrite exhibits higher values of saturation magnetization, lower coercive field and a lower temperature coefficient of coactive, as compared to intrinsic strontium hexaferrite.

A model is developed to assume random occupation of two quasi-equivalent Nb sites. The long range order of the glassy type is analyzed.

The stress-impedance (SI) profiles are measured in Fe73.5Cu1Nb3Si13.5B9 ribbons annealed by Joule heating in the presence of longitudinal applied tensile stress of 100 MPa and the maximum Si ration of 350% is observed. The findings show that the large SI effects are a result of induced transverse magnetic anisotropy.