On the basis of the “column-like” powder model of Warren and Averbach, a profile fitting procedure was devised to obtain microstructural disorder parameters. The interference function

where d is the interplanar distance, λ the wavelength, θ the diffraction angle and N the number of cells within a column, was used to model experimental profiles taking into account the column-like crystallite size and r.m.s. strain distributions. The procedure can be applied both to single peak and to two or more peaks of multiple order of reflection. The method was tested on several samples, also having a bimodal size distribution, and the results compared with those obtained by the well-established Warren-Averbach analysis.

Software has been developed for performing image reconstruction of analytical results from an X-ray microbeam spectrometer. The software system has been developed on a conventional IBM-AT compatible computer and runs under WINDOW 3,0 system. The interactive part is developed as a complete “window-style” program where the operator controls the sample movement, the MCA and the micrograph image from the microscope.

A description of the spectrometer and the software system is given. Applications of the technique in analysing documents are presented.

An X-ray Micro-Fluorescence (XRMF) spectrometer, with an analysis area of about 100 by 150 microns, has been used to collect 2-dimensional X-ray intensity maps over large-area (5 to 50 mm in X and Y) samples. These intensity maps were collected by scanning the sample on an XY stage, and converting X-ray Energy-Dispersive spectra to peak intensities for the elements of interest. The maps, when displayed using false-color or pseudogray scales, show the distribution of individual chemical elements over the analysis area. These maps can be collected at speeds from about 1 minute per frame (analysing 25 elements simultaneously). Greater precision of chemical intensities, or larger area maps, may require several hours, particularly if extensive data processing is performed at each point. XRMF has advantages over more conventional SEM-EDS X-ray mapping, including sample preparation and presentation, as well as improved signal-to-noise ratios.

A technique is described which assists in analyzing the large amount of data which is collected in each map. Principal Component Analysis (PCA) is performed on all of the elemental maps simultaneously. This technique compresses the many elemental intensity maps into a few principal components, resulting in many fewer maps to evaluate. The intensity maps of these principal components display the most pertinent information. They can also be plotted as scatter plots which can help with the partitioning of the data into individual phases. This procedure can potentially be automated as a method for phase analysis. The selected pixels from the scatter plots can be averaged and converted into phase compositions, and the phase information re-displayed on the original elemental or principal component maps.

This technique has been applied to a thin section of rock, and to a synthetic multiphase alloy sample.

Nanocrystalline powders of Fe and W were prepared by mechanical working in a highenergy Spex 8000 mixer/mill. The diffraction patterns were recorded with Co Kα radiation and the line profiles were subjected to a Fourier analysis. The size 〈D〉 of the coherently diffracting domains (x-ray particle size) and the root-mean square strains 〈ε2L〉1/2 were determined with the Warren-Averbach method. In addition, the integral breadths were evaluated and corrected for instrumental broadening assuming Cauchy line profiles. In order to separate particle size and strains, the corrected breadths β(s) = βcosθ/λ were plotted as a function of s = 2sinθ/λ, i.e., β(s) =(1/D) + 2ε s, where D = 〈D2/〈D〉 and ε is a strain averaged over the domain size D.

X-ray fluorescence analysis indicated that the W powders contained an iron and chromium contamination due to the abrasion of the stainless steel balls reaching a value of 24 at% Fe+Cr after 20h of milling. Since W is elastically isotropic, all available (hkl) reflections can be used in the Warren-Averbach and line breaddi analyses. After 20 h of milling, the W powder exhibited a particle size 〈D〉 = 35 Å and a strain 〈ε2〉1/2 = 0.52% at L = 30 Å. The integral breadths yielded the particle size D1 = 70 Å and the strain ε = 0.38%. in the case of Fe powder, also milled for 20 h, the (110) - (220) pair of reflections was used to calculate the particle size and strains. The Fourier analysis yielded the values 〈D〉 = 105 Å and 〈ε2〉1/2 = 0.59% at L = 30 Å. The corresponding integral breadth values are D1 = 280 Å and ε1 = 0.7%. The sum of the particle size Fourier coefficients is equal to the integral breadth particle size D1 = 125 Å, which is very close to value 〈D〉 = 105 Å indicating that the particle or domain sizes have a very narrow size distribution.

X-ray diffraction (XRD) line-broadening analysis has been used to determine dislocation densities in zirconium alloys with hexagonal closepacked (hep) crystal structures and a complex distribution of dislocations reflecting the plastic, anisotropy of the material. The validity of the technique has been assessed by comparison with direct measurements of dislocation densities in deformed polycrystalline and neutron-irradiated single crystal material using transmission electron microscopy (TEM). The results show that-there is good agreement between the XRD and TEM for measurements on the deformed material whereas there is a large discrepancy for measurements on the irradiated single crystal; the XRD measurements significantly underestimating the TEM observations.

A considerable number of the elements and a profusion of organic compounds are emitted into the atmosphere in association with solid and liquid particles. More than 50 percent of all air pollutants are preferentially present in particulate matter rather than in the gas phase. The assessment of the potential environmental and toxic effects of particulate matter in the atmosphere requires a detailed physical and chemical characterization. Methods for analyzing aerosols have recently been extensively reviewed by Maenhaut.

Ferroelectric polycrystalline thin films are being pursued as materials for use in the next generation of radiation hardened nonvolatile semiconductor memories, optical switches and optical computers. Of particular interest are PZT films with a composition near the morphotropic phase boundary. In order to fully understand the the difference in electrical properties as a function of processing parameters it is necessary to fully characterize phase composition and crystallographic properties of these films. Since some films are produced by either spinning or dipping successive layers to obtain the desired thickness it was necessary to compare the properties of each layer.

X-ray diffraction techniques employing parallel beam optics with grazing incidence angle geometry were used to characterize the films. Experimental procedures using sealed tube xray diffraction systems to determine differences in crystallite size and microstrain as a function of depth into the films are a rather unique application of this technique. Discerning the contribution to line broadening due to phase changes, grazing incident angle geometry, crystallite size and microstrain are key to the success of this technique.

This paper discusses the experimental techniques employed and will demonstrate how we were able to successfully determine microstrain as a function of depth into the film. We use transmission electron microscopy (TEM) to aid in the characterization of the films. A brief description of the processing procedures used to produce the films is also provided.

A new type of scanning X-ray diffracto-microscope (SXDM) / X-ray powder diffractometer (XPD) which uses a converged incident beam, was designed, manufactured, and some of its basic characteristics were examined. The optical system consists of asymmetric reflection type curved crystal monochromators for both incident and reflection beams, a detector (FSPC, X-ray film, IP, nuclear plate), a translation mechanism for the specimen and also for the detector.

In this study electrolytic copper powder and atomised high purity iron powders of various size, fractions were consolidated to comparable densities by two very different processes (quasistatic pressing and dynamic, or shook wave, compaction). The resulting pairs of compacts had densities of approximately 0.96 of the theoretical density. These specimens were analysed by X-ray diffraction in order to determine the effect of particle size on the response to compaction.

We developed an X-ray fluorescence element mapping spectrometer (XEMS) based on commercially available energy dispersive XRF equipment several years ago. Using XEMS, we found that this technique is applicable to realtime observation of the elemental distributions in living biological samples. This kind of observation is almost impossible by conventional techniques such as EPMA, PIXE etc. But the spatial resolution of the previous system was about 200pm, Inferior by almost two orders to that of EPMA for example. So we developed a new spectrometer with an improved resolution of better than 20um and almost the same sensitivity.

A scanning X-ray analytical microscope was constructed using X-ray guide tube(XGT). XGT is a glass capillary which guides and focuses x-rays by total external reflection at the inner wall. The nature of X-ray beam passed through XGT is varied depending on the form of XGT. The cylindrical and conical types were used for the present setup. A small area (10μm × 10μm) of the sample was irradiated by the X-ray microbeam formed by XGT. Fluorescent and diffracted X-rays from the small area were detected by SSD. By scanning the sample in the plane normal to the X-ray microbeam, the intensity distributions of such secondary x-rays were measured and used as picture elements for constructing x-ray mapping images. The sample was a thin-section of an old chinaware. The images suggest a wide application of this instrument.

The diffractometer instrumental profiles convoluted by Alexander from aberration profiles calculated using the methods developed Easterbrook, Pike and Wilson include two profiles which are not amenable to exact analytical solution. These two profiles are generated by the axial divergence and flat specimen aberrations. Using ray tracing techniques the exact profiles of these two aberrations have been computed for the Philips PW1050 and Scintag DA5 diffractometers. sample profiles at 2θ = 28°, 90° and 152° have been convoluted with the third asymmetric profile, that due to specimen transparency, and plots of the resultant profiles are shown. Shifts of the centroids and the peaks of the profiles from the true Bragg angle have also been computed and plotted over the range 2θ = 0°-180°.

The success of new electronic materials has been due in part to the development of procedures that produce semiconductors of sufficient purity and perfection. These materials have been grown from the gas phase, solution, and melts. The Bridgman technique is one way semiconductor crystals are grown from the melt. In such furnaces the semiconductor material is usually sealed in an ampoule made of quartz or other suitable material, placed inside the tubular furnace, and heated to completely melt the sample. The ampoule with the molten material is slowly removed from the furnace by one of three ways.

Metallic filaments with sub-micrometer diameters have recently been fabricated using novel materials fabrication techniques at NRL. The specimens are enshrouded in a glass sheath and all efforts to obtain structural information from these samples with conventional x-ray sources have been negative. By using synchrotron radiation on a wiggler beam line, x-ray diffraction data have been obtained from samples with diameters of 0.22, 0.09, 0.07, and 0.04 μm. The two thicker samples were found to be single crystals with a structure consistent with that of normal Bi. Single crystal diffraction peaks obtained from the 0.07 μm sample are incompatible with the Bi-1 or any other known structure of Bi. We have provisionally identified this as Bi-X.

Real time observations of the YBa2Cu3O7-δ (123) melting process by high temperature XRD and optical microscopy reveal a reaction sequence which does not correspond well with the literature. CO2 gas, present in the air, reacts with 123 to produce the Y2CU2O5 phase. This reaction begins well below 800°C and persists up to 970°C when BaCuO2 begins to form. The previously unreported BaCuO2 reaction occurs in either air or oxygen and this phase grows at the expense of the 123 until both rapidly disappear at 1050°C with the appearance of Y2B2CuO5 (211), Formation of Y2O3 from the 211 melt occurs more slowly, beginning at 1150°C. Dynamic 00ℓ orientation has been observed at 950°C upon cooling from the melt. The orientationa) growth is believed to be a surface tension dependent, liquid assisted sintering reaction.

An apparatus based on X-ray microfluorescence has been developed at IRSID in order to routinely and quantitatively determine the state of segregation in steels. The equipment consists principally of an iron anticathode X-Ray tube, a Si(Li) energy - dispersive detector and a “on the fly” operation in a multi-scale analysis mode. The acquisition of a chromium or manganese mapping in a (150 × 150 mm2) steel sample is possible over a total time of about one hour. The calibration curves for chromium or manganese are linear for the usual compositions of steels between 0.3% to 3%.

Synchrotron Radiation Induced X-ray Fluorescence analysis was successfully applied to the analyses of meteorites, archaeological objects and animal tissues. Electronic states of Fe and Ti in chondrules of chondrites were clarified by micro-XANES to be Fe2+ and Ti4+. Ancient iron implement (B.C. 3c A.D. 3c) with zoning of rusts was characterized by micro-XANES. Two dimensional chemical state analyses of the sample were made by selective excitation of iron. Trace element analyses of Cu, Zn, Se, and Hg in the brain and kidney of rat, mouse, and guinea pig dosed with alkyl mercury and/or Se were made from a view point of mercury intoxication. Strong correlation between Hg and Cu, Zn, Se was observed by the correlation analysis of the elemental distributions. The XRF imaging also disclosed decrease of Cu and Zn level in cancerous tissues of human kidney compared with normal ones.

Advantages of Synchrotron Radiation (SR) as an X-ray source of X-ray Fluorescence (XRF) Analysis have been demonstrated by many pioneering researchers. The advantages include wavelength tunability, high intensity and high resolution, which allow us to carry out nondestructive multielemental analysis of trace elements. However, practical application of the SR-XRF is still limited in numbers. The authors expected that the application of SR-XRF is most promising in the fields of archaeological objects, geological samples, and biological samples and started the present research projects in 1987. Now we have established the analytical procedures of these samples by SR-XRF that we report a part of our results, which so far we obtained from the analyses of geological samples, archaeological objects and biological samples.

The techniques of chemical state analysis used in this study are based on the following two approaches: one is XANES (X-ray absorption Near Edge Structure) and the other is SIXES (Selectively Induced X-ray Emission Spectroscopy). It is well known that the former technique together with EXAFS has been developed rapidly with the development of intense SR beams. SIXES was recently established by Sakurai et al. It enables us to carry out chemical state mapping by X-ray fluorescence using absorption edge shifts. This method was first applied to practical problems in this study.

X-ray powder diffraction together with several other analytical techniques have been used to characterize the phase formation and the melt compositions associated with the invariant reactions in the system BaO-½Y2O3-CuOx. In this report, the characterization results of the ternary eutectic reaction of the system, the melting of the high Tc compound Ba2YCU3O6+x, and the melting of the 'green phase' BaY2CuO5 are described. The minimum malting eutectic temperature of the system has been determined to be ≈ 925°C, which corresponds to the reaction of Ba2YCu3O6+x + CuO + BaCuO2 → Liquid. The melting of Ba2YCu3O6+x takes place at around 1015°C to yield BaY2CuO5 + Liquid. The green phase melts around 1270°C to yield BaY2O4, Y2O3 and liquid. All these melts were found to contain only a small amount of Y. Reduction of the copper was found to accompany melting.

Aryloxyphenoxy propionates are a widely manufactured class of highly active grass-selective herbicides for use in various crops. Examples include VERDICT (1a), FUSILADE (1b), WHIP (1c), and ASSURE (1d). Figure 1 shows the general structure of aryloxyphenoxy propionates. All of these compounds contain a chiral center and each enantiomer of the optical pair exhibits significantly different herbicidal activity. The optically active isomers can be prepared by reacting the corresponding substituted phenoxyphenol with the S-(-)methyl lactate sulfonate ester (2). However, the optical yield from this type of reaction is usually less than 85%. Optical purification can be achieved by control of the crystallization.