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The induced Pt magnetization in a Pt/Co/Pt thin film structure is studied. The normally nonmagnetic Pt acquires a magnetic moment due to the magnetic proximity effect at the Co–Pt interfaces. Element specific Pt structural and magnetic properties are characterized by synchrotron-based resonant x-ray reflectivity and x-ray resonant magnetic reflectivity measurements. An advanced analysis method based on Bayesian inference is used for model fitting of the x-ray data. Using this method, we retrieve the best fit values of material parameters (e.g., thickness, interfacial roughness) from the data. Analysis of x-ray reflectivity data of this specific system shows that the Pt magnetization and Co–Pt interfacial roughness is significantly different between the top and bottom Pt layers, with both values being larger in the top Pt. The successful application of this Bayesian method to study the magnetic and structural properties of a thin film system demonstrates its effectiveness for x-ray reflectivity data analysis.

In this study, the influence of interfacial roughness of multilayers structures on spin filter tunneling is investigated at low biases as a function of interfacial roughness type. The results show that the roughness causes the reduction of resonant tunneling, maximum achievable tunneling magneto resistance (TMR), and spin-filtering efficiency of tunneling structures. Based on the numerical results, decreasing the electronic devices’ efficiency is straight related to roughening of interfacial. Additionally, the effect of different temperatures is investigated on the spin polarization (SP). The values of SP decreased sensibly by increasing the temperature.

We investigated the delamination behaviour of diamond-like carbon films on silicon nitride (Si3N4) substrates, considering the effect of the substrates surface roughness. The damage evolution at th...

Interfacial roughness is prevalent in 1D photonic crystals and other layered structures, but is not generally accounted for in their design nor the analysis of their optical properties due to a lack of simple theoretical approaches. We present a transfer matrix formalism to incorporate the effects of interfacial roughness in the optical properties of stratified systems such as 1D photonic crystals and apply it to calculate the optical response of some nanoporous anodic alumina and porous silicon structures. We have validated our formalism by comparing our results to some experiments., Comment: 25 pages, 9 figures

Friction surfacing offers a means of producing coatings between dissimilar materials through a solid state process; a union that would otherwise be classed as incompatible for liquid state coating processes. A method of using a rotating consumable friction rod supplemented by inductive heating was employed to produce conditions necessary for a sound bond between a stainless steel coating and an aluminium substrate. The rotational speed of and load on the coating rod influenced the bond strength significantly with low rotational speeds and high load values producing a good bond quality; however, cavitations at the coating-substrate interface showed a detrimental effect on the bond quality. Mechanical interlocking could be identified from images of longitudinal cross-sectional slices which were recorded using optical microscopy. An image recognition software tool was used to generate an interfacial roughness profile graph which described the coating-substrate interface. Additional filtering of the profile graph showed the depth of mechanical interlocking of the stainless steel coating into the aluminium substrate with the degree of this interlocking quantified by roughness values calculated from the profile graph. Large roughness values can be related to high coating push-off strengths (up to 107 MPa), and also were a result of low rotational speeds and high load values during friction surfacing. Dovetail shaped mechanical interlocks identified in the profile produced both high push-off and shear strength when compared with wedge-shaped interlocks; which, overall, provided good shear strengths up to 126 MPa.

In this paper, a new method to modify Ta underlayers by an argon ion etching technology is introduced. Surface roughness of Ta underlayers, as well as soft magnetic properties of post-deposited FeCoB films can be improved by applying a proper ion etching process. The reduction of magnetic coercivity of FeCoB films deposited on the modified Ta underlayers is attributed to the improvement of interfacial roughness, which can reduce magnetic ripples in magnetic films. The microwave damping linewidth of magnetic films is also found to be related to the interfacial roughness. Ta underlayers modified by the ion etching can reduce the influence of two-magnon scattering effect, and thus tune microwave properties of magnetic films. All the results prove that argon ion etching is an effective way to tailor magnetic properties of magnetic films.

We investigated the effects of the post-oxidation annealing (POA) atmosphere on the electrical properties and interfacial roughness of SiO2 deposited on a 4H-SiC (0001) face and SiC. POA in ammonia (NH3) gave MOS capacitors with a lower interface trap density and n-channel MOSFETs with higher field-effect mobility than POA in nitrous oxide (N2O) or nitrogen (N2). In contrast, POA in N2O gave a lower interface trap density than POA in N2, but it gave the lowest field-effect mobility of all the samples. Cross-sectional TEM observations revealed that N2O POA gave a higher interfacial roughness than NH3 POA. We thus considered that N2O POA degraded the inversion-layer mobility due to increased roughness scattering.

Interfacial roughness is considered as a transition layer. A method of calculation of diffraction scans from multilayered structures with interfacial roughness, which is both fast and free of numerical errors, is developed., Diffraction in multilayers in the presence of interfacial roughness is studied theoretically, the roughness being considered as a transition layer. Exact (within the framework of the two-beam dynamical diffraction theory) differential equations for field amplitudes in a crystalline structure with varying properties along its surface normal are obtained. An iterative scheme for approximate solution of the equations is developed. The presented approach to interfacial roughness is incorporated into the recursion matrix formalism in a way that obviates possible numerical problems. Fitting of the experimental rocking curve is performed in order to test the possibility of reconstructing the roughness value from a diffraction scan. The developed algorithm works substantially faster than the traditional approach to dealing with a transition layer (dividing it into a finite number of thin lamellae). Calculations by the proposed approach are only two to three times longer than calculations for corresponding structures with ideally sharp interfaces.

The interplay between non‐local phenomena during growth and the evolution of interfacial roughness was investigated in Co/Cu multilayers grown by rf ‐magnetron sputtering. In particular, we compared samples where the presence of correlatedinterfacial roughness, namely interface undulations, is more or less pronounced by changing the underlayer or the multilayer stacking. We performed anomalous grazing incidence measurements to observe how the vertical correlation length, ξ ⊥ , changes as a function of the in‐plane length scale of the roughness, L . ξ ⊥ is expected to monotonically decrease with L , but we found that ξ ⊥ displays a maximum for specific L values featuring a high degree of in‐plane correlation. This effect seems to be related with the features of the multilayer stacking.

Interlayer-exchange-coupled (IEC) type spin-valve giant magnetoresistive (SVGMR) films in which the pinning layer does not contain an anti-ferromagnetic layer have been investigated. The IEC-type SVGMR films had good SV properties with a 10% MR ratio as deposited. However, the MR ratio decreased with increasing annealing temperatures over 310°C. From cross sectional TEM observation, interfacial roughness between the free and pinned layers was increased by annealing, and such roughness causes the degradation of SVGMR properties. Thermal stability of SVGMR films was improved when the thickness of Ta capping layer was 5 nm. In order to reduce the thickness of capping layer, various materials of Ru, Cu, and NiFeCr were investigated instead of Ta. No degradation in SV properties after 320°C annealing was achieved with the 2 nm of Ru capping layer.

X-ray reflectivity analyses were performed in the Si/WTi (7 nm)/NiFe (30 nm)/FeMn (13 nm)/NiFe (10 nm)/WTi (7 nm) exchange-biased system prepared by magnetron sputtering under three different argon working pressures. Layer-by-layer analyses were realized in order to obtain the interfacial roughness parameters quantitatively. For a fixed argon pressure, the root-mean-square roughness (including the atomic grading) of the upper (FeMn/NiFe) interface are greater than that for the lower one in all studied samples. Argon working pressure also has severe influence over the NiFe/FeMn interfaces, being more pronounced at the upper interfaces.

GMR multilayer films using Co2MnGe(CMG) and Mn-Ir/CMG exchange-coupled films were fabricated on thermally oxidized Si substrate, and their crystal orientation, magnetic properties, and interfacial roughness were investigated. The main results are stated as follows. (1) (100) oriented MnIr/CMG exchange-coupled films were realized when Ni-Ta underlayer/Cr buffer layer were deposited on thermally oxidized Si substrate. After thermal annealing for 2h at 250°C in a magnetic field of 5 kOe, the unidirectional anisotropy constant (JK) of bilayers was 0.13 erg/cm2. (2) Dependence of saturation field (Hs) on Cr thickness for GMR films with (100) oriented CMG/Cr/CMG trilayer was investigated. Hs was minimum when Cr thickness was 1 nm and 5 nm. (3) Surface roughness (Ra) of Ni-Ta 5 nm on Al-Cr bottom electrode layer(100 nm) was 0.108 nm. (4) Flat and (100) oriented CMG/Cr films was formed on Al-Cr bottom electrode layer (100 nm)/Ni-Ta underlayer (15 nm)/Cr buffer layer (60 nm) when Cr content of the Al-Cr layer was 18.7-24.6 at%.

The use of cryogenic temperatures (∼77 K) during Au Schottky contact deposition onto n-GaAs produces an increase in barrier height from 0.73 eV for room temperature diodes to 0.82 eV. Not all Schottky metals show this enhancement—for example Pt and Ti do not show any significant change in barrier height whereas Au, Pd and Ni show increases between 7 and 18%. We used X-ray reflectivity to show that the main difference between Au deposited at 77 K and room temperature is a decreased metal roughness while the interfacial roughness between the Au and GaAs is basically the same. As the diodes are annealed to 300 °C both the difference in barrier height and interfacial roughness is lost. This is a simple method with potential for improving the performance of GaAs metal-semiconductor-field-effect-transistors (MESFETs).

Recent arguments that the Current-Perpendicular-to-Plane (CPP) Magnetoresistance of Fe/Cr multilayers is sensitive to interfacial roughness stimulated us to try to repeat the experiments on which the claims were made. While our CPP specific-resistances are comparable to those previously reported, their detailed behaviors are different. Our data are consistent with a simple two-current series-resistor model with a single enhanced interface resistance 2ARFe/Cr*=1.6±0.15 fΩ m2, in reasonable agreement with recent calculations. However, our best estimate of the interfacial scattering anisotropy parameter, γFe/Cr=−(0.7±0.15), is larger in magnitude than predicted by the same calculations. We discuss possible reasons for the differences between our results and previous data.

The effects of thermal annealing on CdTe/CdS heterojunctions have been investigated by means of the grazing incidence x-ray scattering technique. Changes in the interface morphology due to heat treatment are characterized quantitatively in terms of a set of parameters including the interfacial roughness and correlation lengths of the layer thickness fluctuations.

The particle packing of MP tape media is explored by means of a new measurement technique. Utilizing a narrow gap length record head, the tape is evaluated throughout its thickness with the use of an incremental DC erase measurement. A quantitative analysis of the medium noise spectra at different erase currents allows for the packing fluctuations at different depths into the tape to be proportioned. The technique provides a method for evaluating the interface between the magnetic recording layer and non-magnetic underlayer in dual-layer tape, and measurements indicate that interfacial roughness at the magnetic coating backside in some dual-layer media is a major source of medium noise.

The giant magnetoresistance (GMR) in magnetic multilayers with current in the plane of the layers is studied by using the quantum-statistical Green's function approach, in which the effects of the interfacial roughness and magnetization configuration on the GMR are included. It is shown that the maximal GMR first increases and then decreases with increasing interfacial roughness, exhibiting a peak at an optimum value of interfacial roughness. An approximately linear dependence of GMR on is obtained, where is the angle between magnetizations of the two successive ferromagnetic layers. Furthermore, the maximal GMR is found to increase with increasing the number of bilayers.

It is known that the quantum well (QW) states in magneticlayered structures can be well described by a phase accumulation model(PAM) in which the phase is calculated by assuming a perfectly sharpinterface. In order to verify the validity of this assumption, we studiedthe effect of interfacial mixing on the phase of QW states inCo/Cu/Co(001) and Co/Cu/Ni(001) systems. By controlling the annealingtime, we progressively increased the interfacial mixing on these films.While the interlayer oscillatory coupling changes upon annealing, thecoupling peak positions remain unchanged. This result suggests that thephase of the QW states have little dependence on the interfacialmixing.

The magnetoresistance (MR) of magnetic multilayers. Fe/Cr and Co/Cu, was measured at high pressure. It was found that the effect of pressure on the MR depends on the specimen: the MR of Fe/Cr decreases much more than that of Co/Cu. The large effect of pressure on the MR in Fe/Cr is shown to be due to the suppression of spin-dependent scattering at high pressure. The relation between the effect of pressure on GMR and the interfacial roughness is discussed briefly.

[Ni80Fe20/Cu](15) multilayers grown by DC-magnetron sputtering and annealed at different temperatures and/or times were investigated by low- and high-angle X-ray diffraction. Structural parameters such as superlattice period, interplane distance, average multilayer coherence length and interfacial roughness were obtained. It was found that as the annealing temperature increases the superlattice period, interplane distance, average multilayer coherence length decrease, while (1 1 1) preferred orientation of the superlattices was improved slightly. The interfacial roughness increases with increasing annealing temperature and/or time. A significant intermixing layer located in the interlayer region between the Ni80Fe20 and Cu layers was revealed by simulating the high-angle X-ray diffraction profiles. The thickness of the intermixing layer increases as the annealing temperature or annealing time increases. (C) 2000 Elsevier Science B.V. All rights reserved.

By studying the variation in magnetic interfacial structure using diffuse x-ray resonant magnetic scattering, underlying connections between the chemical and magnetic interfaces are uncovered and utilized to understand how intrinsic magnetic properties influence the behavior of magnetic interface. By considering the effect of competing magnetic energies (dipolar, anisotropy, and exchange) at the rough interface, it becomes clear how magnetic forces can lead to a reduction of the magnetic interfacial disorder. {copyright} {ital 1999} {ital The American Physical Society}

The microtopography of silicon and silicon oxide surfaces in SIMOX structures is investigated by scanning tunneling microscopy. A method of using scanning tunneling microscopy to study Si/SiO2 interfacial roughness is developed for this purpose. It is shown that the relief of the silicon surface in SIMOX structures is smoother than that of the oxide surface. The observed Si/SiO2 interfacial roughness is due to oxygen ion implantation in the silicon single crystal. The roughness of the SiO2 and Si surfaces at the Si/SiO2 interface is compared for the standard and high-temperature oxidation of the silicon single crystal.

We present experimental neutron reflectivity results showing that it is possible to use V–Ni multilayered systems as cold neutron monochromators and supermirrors. Compared to the Ni–Ti optics devices, the V–Ni stacks present sharp interfaces characterised by a low interfacial roughness and very small interfacial diffusion.

Excitons in a quantum well depend on the interfacial roughness resulting from its growth. The interface is characterized by islands of size $\ensuremath{\xi}$ separated by one monolayer steps across which the confining potential decreases by ${V}_{0}$ for wider wells. A natural length is the localization length ${\ensuremath{\xi}}_{0}=\ensuremath{\pi}\ensuremath{\Elzxh}/\sqrt{{2MV}_{0}}$ characterizing the minimum size island to confine an exciton. For small islands $(\ensuremath{\xi}l{\ensuremath{\xi}}_{0}),$ the absorption spectrum has a single exciton peak. As the island size $\ensuremath{\xi}$ exceeds the localization length ${\ensuremath{\xi}}_{0},$ the peak gradually splits into a doublet. Generally the spectra exhibit the following features: (1) the shape is very sensitive to $\ensuremath{\xi}/{\ensuremath{\xi}}_{0}$ and depends only weakly on the ratio of island size to exciton radius; (2) in the small island regime $\ensuremath{\xi}\ensuremath{\ll}{\ensuremath{\xi}}_{0},$ the asymmetric shape of the exciton peak is correctly described by a model of white-noise potential, except for the position of the peak which still depends on the correlation length of the disorder.

We discuss the viscosity damping effect on capillary waves in a binary-liquid system, using the linearized Navier-Stokes equation. The damping correction for the dispersion relation depends on the wave vector k as well as the interfacial tension. The calculated k-dependence of damping is characterized by a critical capillary-wave-number value , which separates the regions of weak and strong damping. The surface and interfacial roughnesses of a binary liquid system with large liquid depths are calculated and compared to experiments. Although the analysis has been restricted to the classical, macroscopic level, we obtain a noticeable modification from earlier hydrodynamic results for capillary wave damping and liquid-liquid interfacial roughness.

We relate the information about interfacial roughness in multilayers obtained by X-ray reflectometry in the low angle regime to what can be determined from cross-section images taken in a transmission electron microscope (TEM). The interfacial root mean square (rms) roughness for each individual layer can be derived from X-ray reflectometry in specular geometry in Co/Cu multilayer systems. The results are both qualitatively and quantitatively in agreement with results obtained by evaluating cross-section TEM images. Utilising non-specular scans in X-ray reflectometry gives additional details about the growth structure. In Co 1− x Zr x /Cu multilayers we suggest to correlate the Hurst parameter to the grain structure determined by cross-sectional TEM.

We investigate Co/Nb multilayers to explore the spontaneous π-phase shift between the superconducting (SC) layers, which is attributed for causing the non-monotonic change of the SC transition temperature ( T c ) with the ferromagnetic (FM) layer thickness ( t FM ) in several FM/SC multilayered systems. The issue of interfacial roughness is also explored by growing Co/Nb multilayers at various sputtering pressures. Transport measurements show a non-monotonic dependence of T c on t FM , and this dependence is insensitive to the structural variation present in the samples, as measured by X-ray scattering.

A series of type-II GaAs/AlAs superlattices epitaxially grown with different interrupts have been investigated using the techniques of grazing incidence X-ray scattering and diffraction. The interrupts are specifically designed to alter the interfacial roughness in the superlattices for the present study. Various structural parameters including the layer thickness, interfacial roughness, and intra-layer correlation lengths of fluctuations in the quantum-well widths have been determined. These results are compared with measurements made on the same set of samples using photoluminescence and optical imaging techniques.

multilayers on Si(100) were prepared by ion-beam sputter deposition. By using a grazing incidence x-ray reflectivity technique, the layer thickness and interfacial roughness of the multilayers were quantitatively characterized. In particular, the differences in structural features between the on interface and the on interface, as well as the possible inhomogeneity of the layers, were successfully revealed. The x-ray reflectivity results are consistent with the high-resolution electron microscopy observations. The process of the growth of the multilayers is also discussed.

In the present work we report the effect of pressure on the giant magnetoresistance (GMR) of several magnetic multilayers (MML). First, we show the experimental results of the effect of pressure on the electrical resistance and magnetoresistance (MR) of Fe/Cr MML having different thickness of Cr layers t Cr . It is found that the GMR of the samples near the first peak ( t Cr = 9.5 and 11 A ) is affected strongly by applying pressure reflecting the unstable electronic structure but the effect of pressure on the MR of the sample between peaks ( t Cr = 15.2 A ) is very small. The saturation fields H s of Fe/Cr MML increases with pressure. These results are compared with those of other MMLs such as Fe/Cu and Co/Cu systems. Finally, the importance of the magnetic state in the paramagnetic layers or interfacial roughness is pointed out to understand the results in the present work.

We report on the technology and basic electrical properties of ten-fold stacked Nb/Si/Nb Josephson junction (JJ). The problem of making a large number of stacked JJs with identical properties was solved by metallic superlattice preparation technology. The uniformity of Si barriers thickness was examined by low angle X-ray diffraction and cross-sectional transmission electron microscopy. To prevent pinholes in the Si barriers the Nb/Si superlattice was sputtered at the regime at which smoothing of interfacial roughness occurs. The stacked junction exhibit both ac and dc Josephson effects. In the Ic(B) diffraction pattern there is an extra periodicity of about 2–3 G in addition to a larger period of about 21 G.

We report on X-ray magnetic circular dichroism experiments performed on Co/sub 5/Cu/sub 95/ as-quenched and annealed granular alloys with giant magnetoresistance (GMR). Results of the Co-L/sub 2,3/ edges give evidence of a direct correlation between the Co orbital and spin magnetic moment with the Co clusters interfacial roughness, a matter that is critical in the GMR response.

We have investigated the interfacial roughness of a W/Si multilayer sputtered at high Ar gas pressure. The roughness exponents as determined from diffuse X-ray scattering agree well with the Huygens-principle growth model proposed by Tang, Alexander and Bruinsma (TAB). Simple microscopic explanations are given to account for the finding of Edwards-Wilkinson (EW) type growth at low Ar pressure and the TAB growth mechanism at high pressures, as well as for the absence of any scaling according to the Kardar-Parisi-Zhang (KPZ) equation.

The magnetization of buried interfaces and its relationship to interfacial roughness is probed for Co films and Co/Cu multilayers using diffuse x-ray resonant magnetic scattering, a method in which the average diffusely scattered x-ray intensity is compared with the component that reflects magnetic scattering. The comparison demonstrates that the boundary between magnetic and nonmagnetic layers is smoother than the interfacial roughness, with short-wavelength roughness less effective in magnetic scattering than longer-wavelength roughness.

We have shown by simulating the rocking curve data of x-ray diffraction using diffuse scattering theory that crystalline (111)-oriented NiFeCo/Cu superlattices sputtered on similar NiFeCo buffer layers on glass substrates display substantial correlated interfacial roughness as large as 4\char21{}6 \AA{} with moderately large lateral correlation lengths ranging from 180\char21{}300 \AA{}. A detailed study of the structures, electronic transport in the field, and magnetization characteristics of the superlattices demonstrated explicitly that under similar conditions of antiferromagnetic coupling giant magnetoresistance increases with increasing interfacial roughness, consistent with the theoretical expectation that giant magnetoresistance is enhanced by the presence of diffuse interface scattering. The experimental results suggest that interfacial roughness chiefly arises from interface disorder at the interfaces. \textcopyright{} 1996 The American Physical Society.

The existence of a low-Curie-temperature phase for Co/Ge(1 1 1) films is proofed by performing surface magneto-optic Kerr effect measurements at 150 K. The coercive force of the films increases slowly between 7.5 and 15 monolayers, and then increases promptly at larger thicknesses. The different increasing rates of the coercive force can be explained by the different interfacial roughness that influences the pinning of the domain walls.

Recent reports on the current-voltage (I-V) characteristics of SrTiO3 and (Ba,Sr)TiO3 thin film capacitors with Pt electrode suggest that their leakage properties are controlled by Schottky emission from cathode. However, their dynamic permittivities obtained from the Schottky plot are always much smaller than those expected from optical measurements. The most plausible approach to explain this disagreement is to incorporate the effect of electric field enhancement due to interfacial roughness into the Schottky emission model. Electric field at the interface, for the first order approximation, can be given by [(r+t)/r](V/t), where r, t and V respectively denote radius of curvature representing interfacial roughness, dielectric thickness and applied voltage. This model predicts that I-V characteristics are the functions of r and V for the ultimate case of r ≪ t. We have closely studied the I-V characteristics of sputter-deposited SrTiO3 films and have obtained the results which strongly support ou...

Electrostatic fields near the interfaces between conductors and dielectric materials are found to depend sensitively on interfacial roughness. An asymptotic method is outlined for analyzing the influence of arbitrary profiles, where the roughness scale is small compared to the distance between the electrodes generating the electric field. The impact of roughness-enhanced electrostatic fields on various problems is discussed.

A comprehensive review of giant magnetoresistance in spin-valve sandwiches and multilayers is presented, highlighting the experimental and theoretical results which are of particular interest for the development of applications of these systems, especially in magnetic recording technology. The main points discussed include the physical origin of the giant magnetoresistance, the influence of the thicknesses of the magnetic and nonmagnetic layers, the influence of the interfacial roughness, the angular dependence of the giant magnetoresistance, and the ability to obtain linear R ( H ) characteristics. A summary of the properties of some systems among the most promising for low-field applications is given. Some theoretical results, based on an extension to Camley and Barnas's semi-classical theory, are presented. This simple theoretical approach can serve as a tool in the optimization of the thicknesses or number of periods of spin-valve structures.

A theoretical analysis, based on the Fourier transformation approach, has been developed for the frictional pull-out of a single fibre with a rough interface from an elastic matrix. A Fourier series is used to express the amplitude function of the interfacial roughness, and solutions for the fibre pull-out stress are obtained for two different boundary conditions: one models a matrix containing an array of unidirectional fibres and the other a single fibre–matrix system. The interfacial roughness between the fibre and matrix is found to have a pronounced influence on the fibre sliding behaviour.

Exchange bias is a phenomenon that has attracted a great deal of interest in the 50 years following its discovery, but that is still lacking a deep theoretical understanding of its origin in core-shell nanoparticles. We present calculations of ferro-antiferromagnetic core-shell nanoparticles with roughened interfaces and demonstrate a wide dispersion in the calculated exchange-bias field caused by the roughening. Furthermore, we show that the magnitude of the exchange-bias field is strongly correlated with the net interfacial moment in the antiferromagnet, proportional to the degree of the interfacial roughness. This provides new insight into the origins of exchange bias in core-shell nanoparticles.

The roughness of a multiphase interface and the associated topography between silicone oil and an alcohol-based fluid were measured with an atomic force microscope (AFM) and compared with the results of calculations based upon a capillary-wave model. According to this theory, the interfacial roughness of a liquid-liquid interface depends on the density, interfacial tension, and temperature of the liquids. Test samples prepared with both silicone oil and an alcohol-based fluid at various volumetric ratios and controlled temperatures were carefully measured. The experimental results indicate that the interfacial roughness measured with an AFM was consistent with the capillary-wave model. The measured interfacial roughness is influenced mainly by the interfacial tension between the liquids and the temperature-driven Brownian motion of the molecules. Three-dimensional topographical pictures of the interfaces were constructed and archived digitally for subsequent investigation. By employing the outlined method, we examined the microscopic details of interfacial properties, with prospective applications in biochemical and biophysical research.

The interfacial roughness in multilayer films is described by a model in which the parameters are directly related to those of microscopic growth processes. The height‐height correlation function is extracted from this model. Stationary and nonstationary roughness are discussed. The diffuse intensity in diffraction from multilayer films that have various degrees of correlation in roughness between interfaces is calculated. The presence of perfect or partial interfacial roughness correlation can be distinguished unambiguously in the diffusely scattered intensity.

Special techniques are needed to reliably measure the ultra-thin film and interfacial properties. In this review several novel ultra-thin film techniques that were developed and/or adapted are discussed: Fowler–Nordheim electron tunneling current oscillations; spectroscopic ellipsometry (SE); a novel application of SE called spectroscopic immersion ellipsometry; atomic force microscopy along with fractal analysis. Recent results using these novel techniques are reviewed on ultra-thin SiO2 films for film thickness measurements, the kinetics of the initial regime of Si oxidation, and interfacial roughness and the effects of roughness on Si oxidation and interfacial electronic properties.

Within a self-consistent tight-binding approximation with Slater-Koster parametrization the itinerant magnetism of ultrathin Fe-films in a few-monolayer range is treated, for vacuum boundaries as well as with Ag-coating. Within our formalism, also the influence of disorder can be studied. For the boundary layers we obtain a strongly enhanced magnetic moment (e.g. 2.63μ B for a free (110) surface). With Ag-coating, the enhancement is somewhat reduced (e.g. 2.42μ B ), and the Ag-atoms are slightly polarized (≈ 0.1μ B ). Our results extend also to systems which have not been treated hitherto, and agree otherwise with other theoretical investigations and experimental work. Finally, for the first time we study ultrathin films with vacancies and substitutional Ag-impurities, as well as systems with interfacial roughness.