Repetitions of the round robin test on powder diffractometer sensitivity and round robin test of intensity measurements, using two almost identical groups of participants, enabled a comparison to be made of results obtained in different tests. Two forms of corundum test samples were used: (i) sintered plates in tests A8 and A9, and (ii) powder samples in test Bl . A rough comparison of the influence of different methods of specimen preparation from the powder material in different laboratories in test Bl is thus possible with respect to the (almost) uniform sintered plates used in tests A8 and A9. The parameters under investigation were the line positions (and/or inter-planar d-spacing) and intensities of eleven reflections occurring at the 20 angles ranging from 25° to 136° for Cu Kα-radiation

The peak angle 2θp is one of the most commonly measured parameters in powder diffractometry, but there is little understanding of the extent to which the instrument affects this measurement. The majority of theoretical and experimental studies of the effects of instrumental aberrations have been based on the peak centroid 29c. In this investigation we have examined the extent to which peak angles in a conventional powder diffractometer shift for different combinations of divergence slit, Soller slits and receiving slit. The line profile standard SRM 660 (LaB6) was used to generate instrument profiles and X-ray data were collected from a diffractometer fitted with a fine focus Cu X-ray tube and a graphite post-monochromator set for CuKa. The effect of the instrument is greatest at low angles, but shifts arising from axial divergence can also be detected above 2θ=120°. Below 2θ = 40° changing the divergence slits from 0.3° to 1.0°, or removing one of the Soller slits, can move 2θp by up to 0.025°.

Quantitative multicomponent analysis of phases by x-ray diffraction still remains one of the most difficult applications of any element or phase spectroscopic method. The level of quality of XRD quantitative analysis is largely in the hands of the operator, but several relatively new methods for processing basic diffraction data are becoming known and more frequently used, including fulltrace (observed and calculated) subtraction methods (Smith et al, 1988), Rietveld procedures (Bish and Howard, 1988; Taylor and Aldridge, 1993), and chemical “apportionment” target-transformation methods (Starks, et al, 1984). In spite of these new advances, the single or multiple peak reference intensity ratio (RIR, or kj) procedure remains a simple and attractive technique for routine quantitative XRD analysis (Schreiner, 1995; Snyder, 1992; Davis, 1992).

In quantitative x-ray diffraction (XRD) analysis, the reference intensity ratio (ki or RIR) is one of the most important parameters of the reference intensity method (RIM). The ki is a function of the intensity of x-ray reflection and the mass attenuation coefficient of the sample for the “Lki” method (Davis, 1992). The intensities for 00l reflections have been calculated, and also the reference intensity ratios corresponding to the 001 reflection have been estimated in this part of the work, which is very important for investigating the iron influence on the XRD analysis of smectites. The Reynolds’ proposed glycol-expanded montmorillonite structure was used as a basis for the calculations.

We have refined the structures for YBa2Cu2.94Nio.O6Oy (2% Ni) and YBa2Cu2.8ONio.20Oy (6.67% Ni) at y ∼ 6.95 and y ∼ 6.5 contents. Oxygen was reduced by two independent methods: quenching from 690 °C and oxygen gettering at 450 OC, Cu-O bond lengths were calculated based on Rietveld structure refinements for the various samples; they indicate the likely occupancy of Ni in the plane (Cu2) site of the 123 superconductor.

X-ray polycrystalline diffraction was used to track progress toward improving the structural properties of SrS:(Eu,Sm) thin films. These thin films are used as the active layer of the ETOM (Electron Trapping Optical Memory) media. In this study conventional x-ray diffraction and x-ray reflectivity were used to evaluate the effect of two deposition parameters on film structures. Line broadening analysis performed using the Warren-Averbach technique showed the beneficial effects of a hydrogen sulfide reactive atmosphere and the RF magnetron sputtering technique on crystallite size and microstrain. A factor of five improvement in crystallite size and a factor of two reduction in microstrain was observed. Film thickness, density, and interfacial and surface roughnesses were determined for two SrS thin films. The sin2Ψ technique was used to determine the in-plane biaxial stress for two films prepared by different deposition techniques. These films exhibit inhomogeneous stress states with an average stress of less than IMPa.

Residual stresses are a major factor in the reliable operation of multi-layer thin film structures. These stresses may form due to defect incorporation during deposition, recrystallization, second-phase precipitation, thermal coefficient of expansion (TCE) mismatch, etc., as well as local plastic flow, delamination or cracking. In the literature, residual stresses are usually assumed to be constant in the plane of the film. This assumption is sometimes implicitly made, as in the cases where only two psi-tilts are used in the stress determination with the sin2Ψ analysis.

In this paper, we will review the possible causes of heterogeneous stress distributions in thin films and discuss their impact on x-ray stress determination techniques using some new data from W films.

In this study, the equations based on x-ray diffraction theory were developed to determine the thickness of multiple layer thin films. The kinematical expression of the integrated reflected intensity from the substrate and films was corrected for the primary and secondary extinction effects assuming a mosaic crystal model. As an example of the application of the method, thicknesses of a double heterostructure system, namely AlAs/AIGaAs/GaAs, were determined. Good agreement was obtained between the results from the x-ray measurement and scanning electron microscopy data demonstrating high precision of this technique.

Epitaxial AIN thin films grown on sapphire, silicon and silicon carbide substrates were studied using x-ray double crystal diffractometry and transmission electron microscopy to compare the structure, residual stress and defect concentration in these thin films. The AIN thin films was found to have a wurtzite type of structure with a small distortion in lattice parameters which results in a small residual stress of the order of 109 dynes/cm2 in the film. The strain due to lattice parameter mismatch between the substrate and film is too small to account for the residual stress present. The calculated stress from the difference in thermal expansion coefficients between the film and substrate agrees well with the experimental values. Both the x-ray and transmission electron microscopy measurements indicate a low defect density in the AIN thin film grown on 6H-SiC substrate which could be attributed to the small difference in lattice parameters between AIN and 6H-SiC. The defect density in the AIN thin film grown on other substrates were considerably higher. This is the first report of the successful growth of single crystal AIN thin films with such a low concentration of defect density.

Today, many researchers investigate extensively the molecular arrangement techniques for various organic materials at a nano meter scale in order to fabricate the organic thin films with novel electronic and photonic functions. For achieving this purpose, it is most important to understand the mechanism of molecular orientation during a film growth process. Thus, it have been strongly desired to develop the measuring system, which enables us to evaluate the crystal structures and molecular orientations of organic ultra thin films during the growth process. For inorganic materials, structural observations of the films grown by a molecular beam epitaxy (MBE) technique are generally conducted by using a reflection high energy electron diffraction (RHEED) method. But, this method can not be applying for many organic thin films because an electron beam destroy them. Since the organic molecules are stable to the x-rays, x-ray fluorescent and diffraction methods are suitable for such investigations of organic thin films.

Thin film technology is rapidly evolving today, and the characterization of the thin film and its surface have become very important issue not only from scientific but also technological viewpoints. Although x-ray diffraction measurements have been used as suitable evaluation methods in crystallography studies, its application to the structural evaluation of the thin films, especially organic one having the low electron densities, is not easy due to the small amounts of scattering volume and the high obstructive scattering noise from the substrate. However, the x-ray diffraction measurements under grazing incidence will aid not only in overcoming the such problems but also in analyzing in-plane structure of the thin films. Therefore, so-called grazing incidence x-ray diffraction (GIXD) has been recognized as one of the most powerful tools for the surface and thin film studies.

Photoabsorption of x-rays in solids causes primary and secondary photo and Auger electrons. The latter are from self absorption of characteristic radiations which have been produced in the solid by radiative de-excitation of photoionized atoms. Whereas the energy of the electrons at the origin is described by discrete values of a few eV up to nearly the energy of the photoabsorbed photons, we observe after the escape of the electrons from the solid a continuous energy distribution with a superposition of the original line spectrum. This is explained by inelastic collisions of the electrons in the course of their migration through the solid and the subsequent loss of kinetic energy. Since the electron range decreases with decreasing kinetic energy, only a relatively small amount of electrons is able to reach the surface and to escape from there.

Standard applications of quantitative XRF are determinations of composition of bulk specimens, composition and thickness of thin multielement layers and thickness of thin element layers. The theoretical background was given by Sherman, and Shiraiwa and Fujino Numerous approaches like empirical coefficients and fundamental parameters were developed and deliver valuable results. Extending the methods to a quantification of very thin layers consisting of more than one chemical element, it becomes more and more complicated to split the solutions into thickness and composition. The explanation is given by the improving validity of the linear approach for the measured signals in dependence on thickness and composition due to the thin layer approximation exp(x)≈l+x. This leads finally to the finding that measured characteristic signals are proportional to the product c-t, where c represents the concentration of the chemical element under investigation and t the thickness of the layer.

In our paper “Determination of thickness and composition of thin AlxGa1-xAs layers on GaAs by total electron yield (TEY)” we described the principles of the determination of thickness t and Al concentration x employing TEY. The essential experimental quantities are the absorption edge jumps of the-eleraents measured in TEY-mode:

Since the problem asks for the quantification of two unknowns (x,t), at least two TEYjumps are needed. The K jumps of Al and Ga deliver reliable information. From the theoretical approach1,2 of quantitative TEY a nearly linear relationship between the measured TEY jumps and the composition (in wt%) has to be expected. The As concentration varies over the interesting composition range 0<x<0.6 from approximately 50 to 60wt% and causes a similar variation of the TEY jump versus x. In combination with the statistical significance of the experimental data we neglect the TEY K jump information from As.

It has been proposed that the interference effect in grazing incidence/exit X-ray fluorescence can be used as an analytical tool. Though these total reflection related measurements have been widely used because of their inherent high sensitivity to the surface of materials, the interference in case of thin films is most likely to be considered difficult to analyze. The present paper describes the use of the interference effect to provide additional capability to enhance information on a specific interface of a thin film. Detailed interpretation of the angular resolved fluorescence tells us at which interface an element of interest is localized. It can be applied to the thin film of only a few layers or non-periodic multilayers where a regular standing wave is not generated.

Analysis of multi-layer thin films by XRF, using the fundamental parameter method, is a common and accurate method to determine thicknesses and chemical structure, as long as the films contain no hght elements. As an attempt to further extend the method, we present experimental results from single layer films made of carbon and silicon nitride with thicknesses ranging from 100 Å to 1000 Å, from single layer films of cobalt and oxygen matrices with varying oxygen concentration, and from complex multi-layer structures made of a combination of palladium, copper and carbon. The experimental data show a significant deviation from the results computed by the standard fundamental parameter method.

Cobalt, titanium and titanium nitride film thickness standards were deposited. All metal film thicknesses were obtained from x-ray reflectivity (XRR) measurement using a conventional powder diffractometer. The cobalt film thicknesses were also thicknesses were also determined from cross-sectional transmission electron microscopy (TEM) images and scanning electron microscope energy dispersive x-ray spectroscopy (SEM/EDXS) data using the recently developed MUFILM measurement technique. The cobalt film thicknesses obtained using MUFILM agreed well with the XRR results. The metal film standards were used to obtain calibration curves for an in-fab XRF system. The cobalt and titanium nitride film thickness standards were also used to adjust the optical constants used for an in-fab ellipsometer.

Smectites are clay minerals that expand and contract dramatically in response to changes in water vapor pressure. The expansion/contraction behavior of smectite has considerable importance in engineering applications (such as the stability of building foundations and the integrity of clay barriers) and affects hydrologic properties. To understand this behavior we have analyzed several purified, homoionic smectite standards over a wide range of relative humidities using X-ray powder diffraction (XRD) and a new computer-automated humidity-control system.

Humidity was controlled by mixing dry N2 with H2O-saturated (“wet”) N2 produced with a gas-washing bubbler held in a constant-temperature bath set at 35°C. Mixing of wet and dry N2 was controlled with automated MKS mass-flow controllers.

High temperature X-ray diffraction (HTXRD) was used to determine the peritectic melting sequence of BI2Sr2CaCu2O8 (Bi-2212) and Bi-2212+20 wt.% Ag thick films on MgO substrates. The optimized sample preparation technique includes tape casting the powders to form 10μm thick films, and reducing the residual carbon concentration to 1600 ppm by careful thermal treatment before the HTXRD measurements. Lattice parameter analyses were used to determine the compositions of solid solutions present in the partially-melted state. Pour phases form during melting Bi-2212 or Bi-2212 + Ag, including an unidentified phase, (C0,4Sr0,6CuO2, (Ca1,4Sr0,6)CuO3, and (Sr,Ca)0.

Phase equilibria of two superconductor phases, namely the 20K Raveau phase (Bi2.2-xSr1.8+xCuOz, currently referred to as the 11905 phase) and the 80K 2212 phase of the Bi-Sr-Ca-Cu-0 system were investigated. The amount of Ca-substitution of the Raveau solid solution was determined and the solid solution region can be approximately described as Bi2.2+xSr1.8-X-Y CayCu1±x/2Ow (referred to as the Ca-Raveau phase or the 119x5, ‘ with 0<x<0.15, 0<y<0.5. To determine the melting equilibria of the 2212 phase, a procedure involving the use of a wicking technique to capture the melt was applied. X-ray powder diffraction (XPD) and quantitative energy dispersive x-ray spectroscopy (EDS) were used to analyse the phases present in the residual and melt, respectively. The approximate primary crystallization field of the incongruently melting 2212 phase was illustrated.