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Using a multielement antenna, we have performed measurements of the angular dependence of propagating magnetostatic spin waves in a thin yttrium iron garnet film, both in-plane and out-of-plane, and compared the measurements with existing theoretical models. For most magnetic field directions, theory and experiments agree reasonably well. However, there is a range of magnetic field directions where differences between theory and experiment become large. [ABSTRACT FROM AUTHOR]

We report experiments which characterize spin wave propagation in a thin (111) yttrium iron garnet film for arbitrary angles between the in-plane magnetic field and the mode wavevectors. By measuring the magnetic field evolution of the phase of the wave traveling across the film, we deduce the frequency dependence of the wavevector, the dispersion relation, from which the mode velocity follows. Additionally, we observe multiple nodes in the regime of the propagating Damon-Eshbach mode; these arise from avoided crossings associated with the higher, exchange split, standing wave modes along the film normal, the positions of which correlate with the direct absorption measurements of their positions. This information allows a determination of the exchange parameter. Using this technique, we examine the nonreciprocity in spin wave propagation that results from an adjacent metal layer. [ABSTRACT FROM AUTHOR]

Films of L11-type CoPt/NiFe exchange springs were grown with different NiFe (Permalloy) layer thickness (tNiFe=0-10 nm). X-ray diffraction analysis reveals that the characteristic peak position of NiFe(111) is not affected by the CoPt-layer-confirming the absence of any inter-diffusion between the CoPt and NiFe layers. Magnetic studies indicate that the magnetization orientation of NiFe layer can be tuned through varying tNiFe and the perpendicular magnetic anisotropy of L11-type CoPt/NiFe films cannot sustain for tNiFe larger than 3.0 nm due to the existence of exchange interaction at the interface of L11-CoPt and NiFe layers. Magnetic force microscopy analysis on the as-grown samples shows the changes in morphology from maze-like domains with good contrast to hazy domains when tNiFe≥3.0 nm. The three-dimensional micro-magnetic simulation results demonstrate that the magnetization orientation in NiFe layer is not uniform, which continuously increases from the interface to the top of NiFe layer. Furthermore, the tilt angle of the topmost NiFe layers can be changed over a very wide range from a small number to about 75° by varying tNiFe from 1 to 10 nm. It is worth noting that there is an abrupt change in the magnetization direction at the interface, for all the tNiFe investigated. The results of present study demonstrate that the tunable tilted exchange springs can be realized with L11-type CoPt/NiFe bilayers for future applications in three-axis magnetic sensors or advanced spintronic devices demanding inclined magnetic anisotropy. [ABSTRACT FROM AUTHOR]

An improved method for characterizing the magnetic anisotropy of films with cubic symmetry is described and is applied to an yttrium iron garnet (111) film. Analysis of the ferromagnetic resonance (FMR) spectra performed both in-plane and out-of-plane from 0.7 to 8 GHz yielded the magnetic anisotropy constants as well as the saturation magnetization. The field at which FMR is observed turns out to be quite sensitive to anisotropy constants (by more than a factor ten) in the low frequency (<2 GHz) regime, and when the orientation of the magnetic field is nearly normal to the sample plane; the restoring force on the magnetization arising from the magnetocrystalline anisotropy fields is then comparable to that from the external field, thereby allowing the anisotropy constants to be determined with greater accuracy. In this region, unusual dynamical behaviors are observed such as multiple resonances and a switching of FMR resonance with only a 1° change in field orientation at 0.7 GHz. [ABSTRACT FROM AUTHOR]

In this study, FeMn was introduced as an antiferromagnetic (AFM) layer to couple with a singlelayered Co49Pt51 alloy thin film, and it was compared with a Co49Pt51/IrMn bilayer system in exchange bias (EB) effect, to explore the mechanism of spontaneous perpendicular exchange bias (PEB), which has been recently observed in CoPt/IrMn bilayers. Bilayers of CoPt/IrMn and CoPt/ FeMn were prepared under the same conditions by sputtering at room temperature without any inducing field. Although PEB was observed in as-grown CoPt/FeMn bilayers, the loop shape and PEB behavior were found to exhibit different characteristics from those of CoPt/IrMn bilayers. The CoPt (5 nm)/FeMn (10 nm) bilayer has a sheared loop that is similar to a double-shifted loop and a much lower squareness ratio (SQR=0.52) and exchange bias field (He=180 Oe) than the CoPt (5 nm)/IrMn (10 nm) system, which has a rectangular loop shape and a high SQR of 0.97 and large He of 290 Oe. The two systems present entirely different dependences of PEB on the thickness of the AFM layer. CoPt/IrMn exhibits behavior that is typical of most EB systems, but for CoPt/ FeMn, this dependence is more complicated with an unusual peak at an AFM layer thickness of 10 nm. Based on the dissimilar loop shapes and dependences of PEB on AFM thickness, the mechanisms of the spontaneously established PEB in these two systems are considered to differ. Investigations of cross-sectional transmission electron microscopy revealed no apparent difference between the interfacial microstructures of the two systems. X-ray diffraction studies demonstrated the <111> texture of both systems. Therefore, different interfacial spin configurations may be responsible for the dissimilar PEB behaviors in these two FM/AFM bilayer systems. [ABSTRACT FROM AUTHOR]

We herein explore the possibility of obtaining tunable tilted magnetic anisotropy in ordered-CoPt (5nm)/NiFe(tNiFe) bilayers through modifying their exchange spring behavior by inserting Pt and Ru-spacers. The tuning process of tilt angle magnetization of NiFe-layer was systematically investigated by varying the Pt or Ru thickness (tPt or tRu) from 0 to 8nm at different thicknesses of NiFe (tNiFe=1.5, 4.0, and 6.0nm). Polar magneto-optic Kerr effect (p-MOKE) studies reveal that the bilayers grown in absence of spacers exhibit almost a rectangular hysteresis loop. With the insertion of Pt-spacer, the loop becomes more and more tilted as tPt increases; whereas, in the case of Ru-spacer, the nature of the loops is not simply changing in one direction. The estimated SQR⊥ (=θr/θs) values from the p-MOKE loops are found to monotonically decrease with increasing tPt when tPt ⩽ 4nm. In contrast, in the case of Ru-spacer, an oscillatory behavior for the SQR⊥ values is apparent when tRu ⩽ 4nm. As a result, an oscillatory tilted angle of NiFe spin configuration was obtained in the case of Ru-spacer; while a decoupling effect was prominent for the Pt-spacer. The results of present study reveal that the insertion of Pt and Ru-spacers as an appropriate means for realizing tunable tilted magnetic anisotropy in the CoPt/NiFe exchange springs. [ABSTRACT FROM AUTHOR]

We investigate the anisotropic stress dependent magnetic and phonon behaviors in self-assembled CoFe2O4-PbTiO3 (CFO-PTO) nanostructures deposited on SrRuO3 buffered SrTiO3 substrates of various thickness. The increased vertical compressed stress with increasing thickness enhances the vertical magnetic anisotropy of CFO while gradually reducing the vertical polarization of PTO. By applying the magnetic-field dependent Raman scattering, the CFO-A1g and T2g(1) phonon frequencies shift oppositely because of the magnetostriction. Moreover, the PTO-A1 mode intensities anomalously enhance and the A1 and E mode frequencies, respectively, increase and decrease, which prove the existence of the stress-mediated magnetoelectric (ME) effect. This study shows that the ME transmission process is dominated by interfacial stress, which is critical for enhancing the ME efficiency. [ABSTRACT FROM AUTHOR]

We show that the Helfrich deformation can be used for fast response time, low driving voltage reflective displays by using cholesteric liquid crystals under short voltage pulses (∼10 ms). Rather than turning planar domains into focal conic domains through a nucleation process, as used in bistable modes, the fast voltage pulse only deforms the cholesteric planar layers to form wrinkled layers. Since the deformed state is formed through a homogeneous process, quick response times and low operating voltage can be achieved. We studied the effects of alignment layer and dispersed polymer on the stability of the Helfrich deformed cholesteric layers, and found that homogeneous alignment layer and polymer network can inhibit the nucleation process responsible for breaking the layers. [ABSTRACT FROM AUTHOR]

Nanodiamond has recently attracted great attention for its intrinsic luminescence in the visible range which can be used as a tracking marker in many biological applications. In this work, photoluminescence (PL) of nanodiamonds interacting with biological macromolecules, such as proteins lysozyme and albumin, is studied. Proteins were physically adsorbed on carboxylated nanodiamonds surfaces. The PL spectra of the protein-nanodiamond complex were measured. It is shown that the surface passivation can modify the nanodiamond luminescence properties. Changes in shape and spectral positions of the nanodiamond PL band were observed and found to depend on excitation wavelength. We attribute the effects to the surface energy traps and transfer between protein and surface nanostructures, particular the graphitelike nanoclusters. This study is important for the bio and medical applications of nanodiamonds used as a biocompatible label. [ABSTRACT FROM AUTHOR]

We have investigated the spin dynamics of a sputtered Co thin film using our broadband ferromagnetic resonance (FMR) spectrometer. From FMR spectra taken at frequencies of 4–20 GHz, we found that our Co film has a g-factor of 2.25 and a Gilbert damping factor of 4.5×108 s-1, indicating an enhanced spin-orbit interaction compared to bulk material or epitaxial films. Besides the normal FMR mode in the saturated state, we also observed the evolution of the low-field hysteretic behavior in the unsaturated state, which affects the FMR mode as the excitation frequency is lowered from 5.000 to 1.636 GHz. We found that the microwave absorption process persists in the unsaturated state for frequencies higher than 1.868 GHz such that the absorption minima occur at -12 Oe on a down-field sweep and at +12 Oe on a up-field sweep, respectively. [ABSTRACT FROM AUTHOR]

Using perturbation facilitated infrared-infrared double resonance excitation of the 85Rb2 molecule, we have observed spectrally resolved fluorescence to the a 3Σu+ state. We have analyzed the rovibrational energy level structure of the 85Rb2 a 3Σu+ state and derived a multiparameter Morse Long Range (MLR) potential and molecular constants for this state, which can be used to predict term values without needing to solve the radial Schrödinger equation. [ABSTRACT FROM AUTHOR]

In situ x-ray diffraction spectra (25-1000 °C) have been measured as a function of temperature for proton-conducting Ba(Zr0.8-xCexY0.2)O2.9 (x=0.0-0.4) ceramics in CO2 atmosphere. Atomic vibrations before and after exposure to CO2 were obtained by using the micro-Raman scattering (150-1600 cm-1). Ba(Zr0.8Y0.2)O2.9 and Ba(Zr0.6Ce0.2Y0.2)O2.9 reveal a promising thermal stability in CO2 without apparent decomposition up to 1000 °C. However, Ba(Zr0.5Ce0.3Y0.2)O2.9 and Ba(Zr0.4Ce0.4Y0.2)O2.9 exhibit thermally stable below 550 °C and then proceed an obvious chemical decomposition of BaCO3 and Zr0.8-xCexY0.2O2 above 550 °C, which were clearly evidenced by the Raman vibrations of 1057 and 466 cm-1, respectively. A first-order orthorhombic-hexagonal structure transition was confirmed in BaCO3 in the region of 810-850 °C upon heating. This study suggests that the Ba(Zr0.8-xCexY0.2)O2.9 ceramics with x¿0.2 are promising candidates for proton-conducting applications in CO2-containing environment. [ABSTRACT FROM AUTHOR]

A simple method is introduced for studying the afterpulsing effect in InGaAs single photon avalanche photodiode. The afterpulsing probability is obtained through measuring the detection efficiencies of various biasing pulses, while the incident photons are kept constant. The effect of excess bias and temperature on the afterpulsing probability is investigated. When the device temperature is higher than 170 K, the afterpulsing probability is lower than 5% for all excess bias voltages because the trapped carrier lifetime is much shorter than the repetition period. [ABSTRACT FROM AUTHOR]

In this paper, the germanium (Ge) nanocrystals (NCs) are synthesized by using the rapid-thermal annealing and are embedded into a three-layer (SiO2/NCs–Ge/SiO2) capacitor structure. The samples with/without the postmetallization annealing (PMA) treatment are investigated to compare and study the PMA affections. The charge storage characteristics of our samples are investigated with the capacitance-voltage (C-V) hystereses. The frequency independence of hysteresis windows is found and attributed to NCs as slow traps with a large characteristic time constant. The frequency-dependent C-V and conductance-voltage (G-V) experiments are further introduced to study the interface traps and the fast traps induced by the NC formation. In order to extract the related trap characteristics from the measured C-V and G-V, we propose to utilize the equivalent circuit and single-level trap model based on Shakley-Read-Hall theory. Three associated parameters including the areal trap density, trap conductance, and semiconductor capacitances are used to confirm that the single-level trap model is truly appropriate for our samples. It is then found from the model that the areal trap density is high and approaches almost uniform distribution along the valence band and bandgap but significantly reduced and then becomes decreased from valence band to the midgap after PMA treatment. In addition, after PMA treatment, the characteristic time constant becomes smaller for one order of magnitude at the same gate bias. It is attributed to the reduction of trap density and also agrees that the interface traps are dominant and has a small characteristic time constant. [ABSTRACT FROM AUTHOR]

We have studied the effect of the thickness of catalytic Ni film for the growth of vertically aligned carbon nanofibers (VA-CNFs) on glass substrates coated with a conductive underlayer of Cr. Both the pretreatment process through which the catalytic Ni nanoparticles were formed and the growth of well-aligned CNFs were carried out in an inductively coupled plasma chemical vapor deposition (ICP-CVD) system. The VA-CNFs were characterized by scanning electron microscopy, Raman spectroscopy, as well as field emission measurements. The results of VA-CNF growth shows that as the Ni film thicknesses decrease, not only the length but also the density of the CNFs drop, although the density of catalytic Ni nanoparticles increases. The variation of CNF density with Ni film thicknesses is believed to be a result of the detachment of the CNFs from the substrate, caused by the electrostatic force produced by the plasma sheath electric field, as well as an ion-enhanced chemical etching effect due to atomic/ionic hydrogen, during the ICP-CVD growth. A field emission measurement apparatus based on a metallic probe of spherical anode structure was also constructed in this study. An electrostatic image model was employed to determine the electric field distribution on the cathode surface. Along with the standard F-N field emission model, the dependence of field emission current density on the cathode surface electric field, as well as an effective field enhancement factor, were extracted from the current-voltage measurement results. The threshold electric field (Ethreshold, for a current density of 1 mA/cm2) increases from 9.2 V/μm to 13.1 V/μm, and then drops to 11.5 V/μm for the CNFs with Ni film thicknesses of 20 nm, 30 nm, and 40 nm, respectively. The electrostatic model results also indicate that the 20 nm case has the greatest space-charge effect on the emission current, consistent with the growth results that the 20 nm case has the lowest CNF density. On the other hand, the CNF length of the 40 nm case is longer than that of the 30 nm one, while the densities are nearly the same; as a result, Ethreshold for the 30 nm case is higher. [ABSTRACT FROM AUTHOR]

The results of a parametric study on the growth of vertically aligned carbon nanofibers (CNFs) by high-density inductively coupled plasma (ICP) chemical-vapor deposition are reported. We investigated the mechanisms that cause the detachment of CNFs during the growth process by high-density plasma-enhanced chemical-vapor deposition with high substrate bias voltage and atomic hydrogen concentration. A simplified model, combining the Child law for sheath field, floating sphere model for field enhancement at the fiber tip and electric-field screening effect, was employed to estimate the detachment electrostatic force on individual CNFs induced by plasma sheath electric field. The force was found to increase with substrate bias voltage, bias current, and lengths of CNFs, consistent with the experimental observations that CNFs density decreases with ICP power, bias power, and growth time. However, the magnitude of the electrostatic force per se cannot explain the detachment phenomena. The other factor is believed to be the ion-assisted etch of CNFs by atomic hydrogen during the growth process since it was observed that the lower end of CNFs formed earlier in the synthesis process became thinner than the tip end. [ABSTRACT FROM AUTHOR]

During the growth of indium phosphide (InP) crystals, dislocations are mostly generated in a plastically deformed crystal due to crystallographic glide caused by excessive thermal stresses. High dislocation density presented in the InP crystal can reduce the performance, lifetime, and reliability of the InP-based microelectronic and optoelectronic devices/circuits. The generation of dislocations in InP single crystals grown from the melt can be predicted by using a transient finite-element model. This model couples microscopic dislocation motion and multiplication to macroscopic plastic deformation during the crystal growth process. The temperature fields in the crystal are determined by solving the partial differential equations of heat transfer for the vertical gradient freeze (VGF) process. These temperature fields are then employed to the transient finite-element model to study the effects of doping impurities and growth parameters (i.e., imposed temperature gradient, crystal radius, and growth rate) on dislocation reduction in InP crystals grown by different VGF processes. [ABSTRACT FROM AUTHOR]

Dielectric permittivities, Brillouin backscattering spectra, polarization-electric field hysteresis loops, and domain structures have been measured as a function of temperature in relaxor-based ferroelectric single crystals (PbMg[sub 1/3]Nb[sub 2/3]O[sub 3])[sub 1-x](PbTiO[sub 3])[sub x](PMN-xPT) for x=0.24 and 0.34. For PMN-24%PT, a diffuse phase transition which is associated with a broad frequency-dependent dielectric maximum was observed near 380 K. As the temperature increases, the PMN-24%PT crystal gradually develops cubic regions and is fully converted into the cubic state near 375 K. An extra dielectric anomaly appears at 370 K, possibly due to the percolating polar cluster induced by an external electric field. PMN-34%PT exhibits a nearly normal ferroelectric phase transition near 445 K from the tetragonal to the cubic phase. In addition, a weak diffuse phase transition observed near 280 K may result from partial conversion of rhombohedral phase to tetragonal phase. The dielectric thermal hysteresis confirms that the transitions near 280 and 445 K are diffuse first order and first order, respectively. The dielectric permittivities of PMN-24%PT and PMN-34%PT obey the relation, ε[sub m][sup ′]/ε[sup ′](f,T)=1+[T-T[sub m](f )][sup γ]/2δ[sub γ][sup 2], above the temperature of permittivity maximum T[sub m]. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Provides information on a study which examined the hypersonic and dielectric properties of lead zinc niobate-lead titanate single crystal. Experimental procedure; Results and discussion of the study.

Self-seeding free electron lasers (FELs) are capable of generating fully coherent X-ray pulses. However, the stability of output pulse energy of hard X-ray self-seeding (HXRSS) FEL is poor. This letter reports the seed energy stability investigation of HXRSS FEL. For the purpose of a more stable HXRSS FEL, this work suggests a relatively broad bandwidth ρt of crystal monochromator, a relatively long electron bunch with energy jitter (r.m.s.) down to a quarter of FEL Pierce parameter ρ, and a larger Bragg angle θB to improve the seed energy stability. Moreover, the angle jitter (r.m.s.) between the SASE pulse incident direction and the crystal surface should be less than (ρ tan θB)/2, and the relative time jitter (r.m.s.) between the electron bunch and the seed should be less than half of the seed bump duration T t . [ABSTRACT FROM AUTHOR]

Examines the thermal viscoplastic stresses and the dislocation densities in silicon ribbon, using an iterative finite difference method. Description of the Haasen-Sumino material model; Factors that affect the mechanical behavior of silicon crystals; Information on the general constitutive equation for silicon; Details of the variations of the elastic and viscoplastic thermal stresses along the center line of the ribbon.

Deals with a study which investigated the film formation mechanisms in the plasma deposition of amorphous silicon and germanium. Optical properties of hydrogenated amorphous silicon; Observation results of cross-section scanning electron micrographs; Correlation of material quality with the nature of the deposition process.

Examines the underlying mechanisms involved in the heat loading on the accelerator grids and plasma chamber components of multimegawatt ion sources. Heat loading due to arc discharge; Mechanisms occurring in the accel column that contribute to heat loading on the source components; Variation in power deposition with change in decel voltage; Effect of variation of the beam perveance on heat loadings.

The histogram and jump-walking algorithms are combined to deal efficiently with the problem of slow barrier crossing in Monte Carlo simulations. The utility of the histogram/jump-walking scheme is illustrated by application to the (Ar)13 and (H2O)8 clusters in their ‘‘phase transition’’ regions. Slow barrier crossing behavior is particularly acute for (H2O)8 as modeled by the TIP3P potential. Even in this case, the histogram/jump-walking algorithm proves to be quite successful at attaining equilibrium. [ABSTRACT FROM AUTHOR]

It is found that (H2O)8 possesses two nearly isoenergetic structures, one with D2d and the other with S4 symmetry, and that the (H2O)8 cluster undergoes a transition between a ‘‘solidlike’’ phase (dominated by the S4 and D2d structures) and ‘‘liquidlike’’ phase at a temperature near 119 K. [ABSTRACT FROM AUTHOR]

Analyzes the structure and crystallinity of cadmium sulfide (CdS) thin films using x-ray diffraction. Applications of CdS thin films; Analysis of the temperature dependence of photoluminescence spectra; Technique used to grow semiconductor microcrystals on glassy dielectric matrixes; Effect of postannealing time on the grain sizes of CdS thin films.

Describes a crystallographic methodology for modeling dislocation dynamics in gallium arsenide (GaAs) crystals grown from melt. Presentation fo a constitutive model for dislocation multiplication of GaAs; Analysis of active slip systems in GaAs crystals; Dislocation multiplication in each slip system.

Focuses on a study which discussed the influence of substrate temperature on the radiation-induced lattice strain field and crystalline-to-amorphous phase transition in MeV oxygen ion implanted gallium arsenide crystals. Techniques in active doping; Relationship between implantation condition aand structure; Distribution of radiation-induced defects.

Presents information on the determination of strain perpendicular to the surface and of the damage in silicon single crystals irradiated by ions. Application of double-crystal x-ray diffraction and dynamical x-ray diffraction theory; Use of Monte Carlo simulation of ion energy deposition; Deconvolution of strain and damage profiles from the x-ray rocking curves of ion-implanted samples.

The temperature dependence of infrared absorption spectra of CH and CD on diamond nanocrystal surfaces has been investigated. Phase relaxation was closely examined by analyzing frequency shifts and line broadening in the spectra. Based on the model of Persson and Ryberg [Phys. Rev. B 40, 10 273 (1989)], coupling phonons responsible for the pure dephasing process were found to resonate at ω0≊1200 cm-1 for the CH stretch. By including both the phase and energy relaxation in the linewidth analysis and assuming that energy relaxes via three-phonon emission, we estimate a pure dephasing time of T*2≊340 ps at room temperature. This value is one order of magnitude larger than the energy relaxation time, T1≊19 ps, measured by Chin et al. [Europhys. Lett. 30, 399 (1995)] on a C(111) single crystal surface. We interpret the anomalous observation to be the result of the high frequency of the coupling phonons. For the CD stretches, however, severe line broadening due to exceedingly rapid energy relaxation disallows accurate determination of T*2. Since CH and CD stretches have similar thermal and inhomogeneous broadening characteristics, the lifetime of the latter is estimated to be T1≊220 fs. This T1 value is one of the shortest vibrational energy relaxation times for any adsorbate on a dielectric surface. Systematic comparison of these anomalous results with the measurements of SiH stretches on Si(100) and Si(111) is given. © 1996 American Institute of Physics. [ABSTRACT FROM AUTHOR]

The 4 3Σ+g, 3 3Πg, and 2 3Δg states of K2 have been studied by perturbation facilitated optical–optical double resonance spectroscopy for the first time. Molecular constants of those states are derived and compared with theoretical calculations. Varying the trial vibrational quantum numbers of these upper states, absolute vibrational quantum number assignments are obtained by comparison between the observed resolved fluorescence intensities and the calculated Franck–Condon factors. The Rydberg–Klein–Rees potential curves are constructed and compared with theoretical calculations. Finally, the observation of the lowest ‘‘dark’’ vibrational levels of the b 3Πu state by resolved fluorescence from the 2 3Δg state confirmed the absolute vibrational numbering of this state and allowed refinement of the b 3Πu molecular constants. © 1995 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Presents a study that examined the effect of indium doping in the graded-index regions of the indium (In)-gallium (Ga)-arsenic (As)/GaAs/aluminum-Ga-As graded-index separated confinement heterostructure quantum well laser. Effect of thermal treatment on laser performance; Importance of InGaAs/GaAs/AlGaAs strained graded-index separated confinement heterostructure quantum well lasers.

Presents a study on the role of cladding layer thickneses on strained-layer InGaAs/GaAs single and multiple quantum well lasers. Introduction to InGaAs/GaAs GRIN-SCH lasers; Analysis of the transverse modes of the GRIN-SCH structures; Details of the experiments.

Reports on the structural and electronic properties of hydrogenated amorphous silicon-germanium alloys deposited by radio frequency glow discharge from SiH[sub4] and GeH[sub4] in a diode reactor. Samples used in the study; Information on deposition conditions and alloy composition; Hydrogen bonding.

Deals with laser-pulse vaporization of uranium dioxide and other refractory materials. Overview of previous studies on the effect of high-power-density laser pulses on solids; Details of a mathematical formula in determining the kinetics of evaporation in low-power density laser vaporization; Changes in vapor flow due to collisional effects.

Provides information on a study which determined the film thickness, chemical state, and polarization screening for hydrogenated amorphous silicon nitride films deposited by glow discharge over hydrogenated amorphous silicon. Indication of the correlation of the defect absorption with the electron spin resonance measurements; Factors important in describing the quantum confinement in superlattices and charge injection into the nitride.

Studies the thermal reaction of Pd/InAIAs contacts using capacitance voltage (C-V) for transistor buried gate technologies. Experimental procedure used; Comparison of the results to those of Pd/A1GaAs and Pd/InGaAs systems; Results and discussion of the study.

Presents information on a study that investigated the barrier properties of metalorganic chemical-vapor-deposited tantalum nitride and physical-vapor-deposited TaN between copper and silicon. Experimental procedure; Results and discussion on the study; Conclusions.

Presents a study which examined the compositional disordering of InGaAs/GaAs superlaticces using a low-temperature-grown GaAs cap layer by molecular beam epitaxy. Introduction to compositional disordering; Methodology; Results and discussion.

Presents information on a study which described the modification of the superconducting YBa[sub2]Cu[sub3]O[sub7-x] films synthesized by a microwave plasma-enhanced pulsed laser deposition process. Comparison of the growth behavior of the thin films with a conventional pulsed-laser deposition process; Experimental details; Results and discussion; Conclusions.

In this study, perpendicular exchange bias (PEB) effect in the as-grown Co49Pt51/IrMn bilayers was demonstrated at room temperature using single-layered Co49Pt51 alloy thin film as ferromagnetic (FM) layer. Several unusual features were observed in this system, viz.,: (i) the PEB was spontaneously established without any external magnetic field treatments, (ii) single-shifted loops were obtained rather than double-shifted ones, and (iii) the spontaneous PEB effect was accompanied by a reduction in perpendicular coercivity, Hc⊥ from 1024 to 632 Oe. The results of x-ray diffraction revealed the formation of IrMn (111) texture. Training effect studies indicate that the PEB effect is stable in this system with less than 5% variation in PEB value within 15 repetitive scans. Significant reduction in the PEB effect was found for the CoPt/IrMn films either grown or subjected to post-annealing under external magnetic field (Hind). The thickness dependence of PEB effect with respect to the FM and antiferromagnetic layers were also investigated and a largest PEB value of 533 Oe was obtained for the sample grown with 3-nm thick CoPt and 10-nm thick IrMn layers. The results of present study thus establish an opportunity to realize PEB effect in the absence of external field during fabrication. [ABSTRACT FROM AUTHOR]

Ultrathin CoFeB/MgO/CoFeB system with perpendicular magnetic anisotropy is a promising candidate for the high density magnetic random access memory. However, a dipolar interaction between the CoFeB layers may introduce a minor loop shift (Hs) and causes uncertainty during the operation. In this report, we systematically studied the dipolar effect in these structures and found that the coupling may be either ferromagnetic or antiferromagnetic (15 Oe>Hs> - 15 Oe) depending upon the CoFeB thickness (0.9-1.4 nm). A modified Fabry-Perot model, which accounts the Bloch wave interference, may explain the present observations of the dipolar effect in the perpendicular junctions of CoFeB/MgO/CoFeB. [ABSTRACT FROM AUTHOR]