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We have studied exchange coupled FePt/Fe magnetic layers using the technique of ferromagnetic resonance (FMR). The FePt layers show strong uniaxial perpendicular anisotropy, growing in the L10 epitaxial phase on MgO (100). We have considered the case for two thicknesses of Fe: 2 nm and 3.5 nm, which exhibit rigid magnet and exchange-spring behavior. All FePt thicknesses are limited to 10 nm. The FMR results display multipeaked spectra, where we have identified three Fe resonance lines in the RM sample and an extra two in the ES sample. Angular FMR studies show a strong uniaxial anisotropy induced in the Fe layer via the strong exchange coupling with the FePt film. An additional uniaxial component is also observed with an easy axis inclined by about 50[degrees] from the film normal. Supplementary magnetic measurements aid with the magnetic characterization. We also discuss the elements for the theory of FMR in these exchanged coupled systems. Index Terms--Exchange spring, magnetic bilayers, magnetic resonance, perpendicular anisotropy.

This work presents Raman spectra obtained from thin films of protein materials which are commonly used as binding media in painted works of art. Spectra were recorded over the spectral range of 3250-250 [cm.sup.-1], using an excitation wavelength of 785 nm, and several bands have been identified in the fingerprint region that correspond to the various proteins examined. Differences in the C-H vibrations located between 3200 and 2700 [cm.sup.-1] can be accounted for with reference to the amino acid composition of the protein-based binding media as well as the presence of fatty acid esters, in the case of egg yolk. In addition, the discrimination of different proteins on the basis of variations in spectra between 3200 and 2700 [cm.sup.-1] can be achieved following multivariate analysis of a large data set of spectra, providing a novel and nondestructive alternative based on Raman spectroscopy to other methods commonly used for the analysis of proteins.

The effect of strain energy and substrate surface roughness on the preferred orientations on amorphous substrates is examined. X-ray diffraction (XRD) analysis is used to compare the preferred orientations and intrinsic stresses of silver thin films deposited on substrates with different surface roughness.

We demonstrate how grating-coupler assisted infrared reflection absorption spectroscopy can be used to simultaneously determine the chemical identity and relative thickness of organic thin films. With a grating substrate, a threshold anomaly associated with passing off of the - 1 diffracted order occurs at grazing angles of incidence, resulting in a sharp absorbance in the infrared. The position of this peak is sensitive to the grating geometry as well as the dielectric environment near its surface. Thus, shifts in the peak position can be used to determine the relative thickness of adsorbed films or quantify molecular adsorption events. To illustrate the characteristics and sensitivity of this phenomenon, several samples were prepared and tested, including self-assembled alkanethiolate monolayers with 11-mercaptoundecanoic acid, 11-mercapto-1-undecanol, decanethiol, and a covalently linked layer of bovine serum albumin on a commercial, gold-coated grating. For these samples, the position of the threshold absorbance peak shifted to lower wavenumbers as film thickness increased, which is consistent with calculated shifts based upon an increasing refractive index at the interface. The sensitivity of this shift was measured to be 3.7 [cm.sup.-1] [nm.sup.-1]. These results illustrate how a grating substrate can be exploited in a standard infrared reflectance measurement to provide additional information about the relative thickness of adsorbed surface films.

The absorption spectra of dye-doped polymer thin films made from a variety of five dyes and six matrices, either organic or organomineral, are analyzed to evaluate the residual absorption in the red wavelength tail and in particular at amplified spontaneous emission (ASE) wavelengths. An absorption cutoff wavelength is defined as the extrapolated wavelength at which the absorption losses are expected to become negligible compared to the structure losses. Such absorption-spectrum-extrapolated wavelengths are compared to the ASE wavelengths and found to correlate for most of the dye-matrix couples. The propagation losses of PM597-doped organic polymers are also measured and accordingly found to increase with the glass transition temperature of the host matrix. OCIS codes: 160.3380, 160.4890, 160.4760, 310.2790, 310.6860.

The triplet spectra and dynamics in two types of oligomeric films deposited by thermal evaporation and spin coating techniques are described. The results demonstrated that even minor changes in molecular packing related to density and interaction could lead to large modification in triplet dynamics.

The reliability of tunable ferroelectric thin film capacitors is analyzed. The effect of illumination of the ferroelectric film by ultraviolet light on the tunable performance of the capacitors is examined.

Thin films of [Pr.sub.1-x][Ca.sub.x]Mn[O.sub.3] deposited on LaAl[O.sub.3] and SrTi[O.sub.3] substrates are analyzed by Raman spectroscopy at low temperatures in order to examine the effect of strains from the Ca doping or the substrate. The BM, the deformation potentials and the Gruneisen parameter of the [A.sub.g](2) mode are calculated for the thin films.

Scanning microdiffraction topography is used for determining the mismatch strains and local strain distributions in silicon-on-insulator substrates with overlying thin film stressor features. The studies have shown that it is possible to deduce the sign of the mismatch strain by inspecting the microdiffraction topograph.

The elastic recoil detection analysis is used for analyzing the evolution of the coating stoichiometry with pressure, target-substrate distance and angle for dc sputtering of [Ti.sub.x]B (x = 0.5, 1, 1.6) compound targets. The pressure, distance and sample position induced changes in chemical film composition is understood by using gas scattering and the angular distribution of the sputtered flux.

The growth of the c-axis oriented aluminum nitride (AlN) thin films on (100) silicon is examined by reactive dc magnetron sputtering at low temperature, which has considered the effect of the magnet configuration on plasma and film properties. The studies have shown that the choice of the magnetron configuration has modified the plasma characteristics and has influenced the film properties.

Fluorescence emission and excitation spectra of single poly(2-methoxy-5-(2'-ethylhexyloxy)-p-phenylene-vinylene) (MEH-PPV) polymer molecules dispersed in thin poly(methylmethacrylate) (PMMA) films are recorded at 1.2 and 20 K. The failure to observe zero-phonon lines of chromophores serving as donors in intramolecular energy transfer is attributed to fast transfer rates, which has resulted in strongly broadened lines which escape detection even at 1.2 K.

Coherent phonon spectroscopy of a-plane wurtzite InN epitaxial thin film is shown with time-resolved second-harmonic generation method and coherent [E.sub.1](LO) phonons are launched via a transient electric field screening process. The examination of the coupling modes have helped in understanding the ultrafast carrier and phonon dynamics in a-plane wurtzite InN.

Magnetic thin films are obtained by radio frequency (rf) sputtering from an amorphous [Fe.sub.78][B.sub.13][Si.sub.9] target. The spin reorientation transition (SRT) and stripe domain structure are studied as a function of thickness and sample microstructure.

An analytic method is described for determining the sheet resistance [R.sub.sq] of symmetric planar four-terminal devices based on resistance measurements. The method has made it possible to monitor [R.sub.sq] of a device during its lifespan and to monitor the aging of the thin films, semiconductor diffusions, and sensor layers in situ.

An analytical model is presented to interpret nanoscale capacitance microscopy measurements on thin dielectric films. The results are used for discussing the capabilities of nanoscale capacitance microscopy for the quantitative extraction of the dielectric constant and the thickness of thin dielectric films at the nanoscale.

The sputtering technique is used for depositing very thin Au layer on Si(100). The atomic force microscopy measurements have helped in studying the roughness evolution of the sputtered Au thin film.

The underlying physics between interfacial layers and retention loss at different temperatures in ferroelectric thin films are studied by using the in-series capacitor model. The ultimate remanent polarization depending on the product of coercive voltage and interfacial capacitance has reduced with the elevated temperature.

The structure, magnetism, and transport in strained epitaxial [La.sub.0.5][Sr.sub.0.5]Co[O.sub.3] (001) films deposited on SrTi[O.sub.3] (001) substrates by reactive dc magnetron sputtering are examined. The results have shown a thin layer at the film/substrate interface with different structural properties to the bulk of the film, as well as a strongly graded magnetic and chemical profile at the film surface due to the significant roughness.

An alternative approach is described based on X-ray magnetic circular dichroism (XMCD) in reflection geometry (R-XMCD) for surface element-selective examination of magnetic properties avoiding intrinsic absorption-related problems. This approach is used for discussing the presence of a narrow surface region with strongly depressed magnetic properties in [La.sub.2/3][Ca.sub.1/3]Mn[O.sub.3] thin films.

Two cathodoluminescence piezospectroscopic (CL/PS) approaches are used for measuring the residual stress distribution in thin films and they are examined by using an intrinsic GaN film sample grown on a (0001)-oriented sapphire substrate. The CL/PS method is shown to be very effective in microscopic stress assessments and has a potential to become a routine procedure in the FE-SEM in the search for quantification/optimization of the residual stress state in thin films.

The effect of the presence of folding defects, the ripple dislocations, on the crack propagation in a wrinkled thin film of gold deposited on polydimethylsiloxane (PDMS) is analyzed. The crack dislocation interaction has shown that the ripple dislocation has an internal stress field.

The current-carrying capability of high quality epitaxial Mg[B.sub.2] films prepared by using the hybrid physical-chemical vapor deposition method is studied by using transport measurement in nanobridge constrictions and magnetization measurement. An extremely high self-field critical current density is observed, which has shown an excellent current-carrying capability in these films.

Ultraviolet photoelectron spectroscopy and atomic force microscopy (AFM) are used for examining the energy level alignment and growth morphology of pentacene (Pn) films deposited on a PMMA derivative-based dielectric surface with and without ultraviolet/ozone treatment. The hydrophilic nature of the treated surface has allowed for a larger grain size of the Pn film, which has contributed to device mobility.

A new microscale Hall effect measurement method is described for characterization of semiconductor thin films without need for conventional Hall effect geometries and metal contact pads. On a cleaved silicon ultrashallow junction sample, the carrier mobility, sheet carrier density and sheet resistance from micro-four-point probe measurements are determined.

The weak solution of the Dirichlet extremum problem associated with the thermal grooving is applied for the simulation of critical grain-boundary (GB)-groove topographies, which has covered the inclined GB configuration. The simulation profiles have agreed with the experimental atomic force microscopy photographs after linewidth matching procedures and the simulations have produced very accurate mean surface diffusivities of alumina and tungsten.

In situ stress measurements during sputtering of amorphous [Fe.sub.80][B.sub.20] films are described. The Monte Carlo simulations of the sputtering process has described the results as a function of the Are pressure and target bias voltage.

A study was conducted to understand the growth mechanism and the chemical bonding states of nitrogen doped ZnO films under monodoping, codoping, and cluster doping with Ga. The chemical bonding of nitrogen in ZnO is found to be critically affected by the N/Ga flux ratio and tuning the N/Ga doping ratio could enhance the formation of desired dopant species, Ga-[N.sub.2][O.sub.2] (codoping), Ga-[N.sub.3]O and Ga-[N.sub.4] (cluster doping) for p-type ZnO.

A theoretical model was developed to evaluate the difference between the work in the oscillating load-depth profiles obtained with and without delamination for a coating film. The observations for the oscillating load-depth cycles appearing after delamination provide insight into the film-substrate contact behavior occurring during the loading/unloading process on one oscillating cycle.

The potential and device physics of interdigitated thin-film solar cells with different spatial sizes, band offsets and material parameters are studied. The nanaoscale interdigitated junctions are shown to be extremely helpful in improving the performance of the solar cell.

A combination of x-ray absorption spectra and other techniques is employed to explain the relationship existing between the local order, long range order and sub-band-gap defects present in hafnium oxide and hafnium silicate films. The observed features are shown to be persistent with the increasing thickness and crystallinity of the films.

Spectroscopic ellipsometry in a broad spectral range from near-infrared to vacuum ultraviolet were utilized to study the thin films of spirobifluorene-type materials such as spiro-octol and spiro-octo2. Both organic materials exhibited intense absorption structures in the blue-uv energy range, a property which can find potential use in optoelectronic applications.

The atomic layer deposition of iridium and iridium oxide films is examined by using an alternating supply of (ethylcyclopentadienyl)(1,5-cyclooctadiene) iridium and oxygen gas. The phase transition between Ir and Ir[O.sub.2] has occurred at the critical oxygen partial pressure during the oxygen injection pulse.

The molecular weight dependence of the conductivity of poly-3-hexylthiophene (P3HT) films are systematically correlated by using noncontact optical pump terahertz (THz) probe spectroscopy. The measurements of P3HT are presented as a function of structural regularity, dispersing solvent, addition of [C.sub.60] electron traps, sample temperature and other growth parameters.

X-ray photon spectroscopy and x-ray diffraction analysis are conducted on NiO and Ti doped NiO samples in order to examine the mechanism behind bistable resistance switching in NiO thin films. High initial resistivity is required for samples to undergo bistable resistance switching and the presence of metallic Ni content is determined in these samples.

The dielectric properties associated with the electronic bonding structures of Si[O.sub.2] films are examined by using the Si [L.sub.3,2]- and O K-edge x-ray absorption near-edge structures (XANES) and valence-band photoemission spectroscopy (VB-PES) methods. The enhanced O 2p and Si 3p hybridization has shown the shortening of the average Si-O bond length, thus showing an increase of the density.

The effect of annealing temperature on amorphous carbon nitride thin films is examined. The results of Raman spectroscopy have shown that the films below 400 [degree]C consists of aromatic cluster component and polymeric component.

The optical properties of the perovskite SrHf[O.sub.3] thin films are examined by using spectroscopic ellipsometry. The studies have shown that SrHf[O.sub.3] thin film is a better insulator than SrTi[O.sub.3] (STO) in the crystalline or amorphous state.

The time evolution of the density of defect states in tritiated hydrogenated amorphous silicon (a-Si:H:T) thin films are analyzed by using the constant photocurrent method (CPM) and isothermal capacitance transient spectroscopy (ICTS). The studies have shown that the concentration of positively charged dangling bonds [D.sup.+] states has decreased with time in tritiated amorphous silicon, while the concentration of negatively charged dangling bonds [D.sup.-] states has increased.

In situ x-ray absorption spectroscopy is used for investigating conformation and molecular orientation of rubrene films grown on Au(111) and Si(111). Ex situ atomic force microscopy measurements show that rubrene film grown on Au(111) is crystalline and the growth direction is along its crystallographic c axis.

Silver nanostructured films are produced by supersonic jet deposition of nanoparticles, which are generated by laser ablation of microparticle aerosols (LAMA). The analysis has shown that increases in conductivity during annealing at temperatures less than 400 degree centigrade has resulted from grain size coarsening rather than densification.

X-ray photoelectron spectroscopy (XPS) and reflection electron energy loss spectroscopy (REELS) are used for studying the electronic properties of ultrathin [(Hf[O.sub.x]).sub.x][(Si[O.sub.2]).sub.1-x] dielectrics, deposited on Si(100) by atomic layer deposition with x equal to 0.75 and 0.25. The results have shown that when Hf-based thin films are used as gate dielectrics in metal-oxide semiconductor (MOS) transistors, the d states of Hf has strongly affected the electronic structure.

The effects of varying the structural parameters of two-dimensional (2D) square lattice Si[O.sub.2] photonic crystal (PC) arrays on the efficiency of extraction of the photoluminescence PL) of sputter-deposited [Y.sub.2][O.sub.3]:[Eu.sup.3+] thin films are examined. The discrepancy between the enhanced ratios of the integrated PL intensity of the as-grown and post-annealed 2D PC layer (PCL) assisted [Y.sub.2][O.sub.3]:[Eu.sup.3+] thin films are due to the effects of crystal phase and the presence of cracks in the 2D PC structures.

A variational principle is used for obtaining upper bound, estimates of the Knudsen transmission probability of many porous slabs of finite thickness. The variational calculations and multiple scattering methods have advantages for the solution of many transport problems with complex geometries.

The room-temperature first and second order Raman spectra of nonpolar a-plane GaN film grown on r-plane sapphire are measured. All of the phonon modes the selection rules allow are seen in the first order Raman spectra and the second order phonon modes are composed of acoustic overtones, acoustic-optical and optical-optical combination bands and optical overtones.

Electrically detected magnetic resonance (EDMR) and electron paramagnetic resonance (EPR) are used to examine emeraldine base polyaniline films. The results have shown that EPR signals are composed of a surface and a bulk contribution and the competition between oxygen and water adsorption on the surface has accounted for the observed differences.

The distance tunneling spectroscopy (DTS) and distance dynamic force spectroscopy (DDFS) was used to investigate the measurement of the thicknesses of ultra-thin water films. The comparison of both the method showed that dynamic force spectroscopy provides the most accurate values but is time consuming so DTS method could still be used if calibrated by the more accurate DDFS method.

Si magic-angle-spinning nuclear magnetic resonance (MAS NMR) spectroscopy was carried out for a series of self-assembled porous silica samples prepared by varying the dimethyldiethoxysilane (DMDEOS) concentration in precursor solution to clarify the origin of their higher mechanical strength. Based on the results it is concluded that the enhancement of Si-O-Si network formation by adding DMDEOS into TEOS-based precursor solution increases the skeletal mechanical strength.

The crystallization of amorphous silicon (a-Si) thin films by the self-propagation of copper oxide/aluminum thermite nanocomposites is presented. Raman spectroscopy is used to analyze the crystallization of a-Si.

Differential scanning calorimetry (DSC) and infrared spectroscopy of thin films is used to investigate the water and sulfuric acid-rich regions of the [H.sub.2]S[O.sub.4]/[[NH.sub.4].sub.2]S[O.sub.4]/[H.sub.2]O ternary liquid/solid phase diagram. It shows significant differences both in the final melting points and in the location of some of the phase boundaries including a significant discrepancy in the invariant points predicted versus those observed.