A synchrotron radiation X-ray micro analyzer(SRXMA) was developed at Photon Factory in Japan. The present SRXMA combines a double crystal monochromator and mirror optics and either a white or a monochromatic microbeam can be used. Micro X-ray fluorescence analysis was carried out, and a minimum detection limit of 1 ppm for Mn was obtained for 100 sec measurement with the white beam. With monochromatic beam excitation, micro X-ray spectroscopies are now feasible.

The obtained beam size was 1.6 μ;m - 34 μm* The beam was blurred in one direction by the scattered X-rays caused by the surface irregularities of the focusing mirror. Improvements in the mirror quality will ensure a beam spot of just a few microns with sufficient intensity.

The availability of intense x-rays from synchrotron radiation sources permits the elemental analysis of samples in new ways. An x-ray microprobs using these sources allows the analysis of much smaller samples with greatly improved elemental sensitivity. In addition to the higher x-ray intensity obtained at synchrotron sources, the development of high efficiency x-ray reflectors using multilayer coated optical mirrors permits the achievement of spot sizes of less than 10 μm x 10 μm with enough x-ray intensity to simultaneously measure femtogram quantities of many elements in less than one minute. Since samples to be studied in an x-ray microprobe do not have to be placed in a vacuum, almost any sample can be conveniently analyzed. With an x-ray microprobe it is possible to obtain elemental distributions of elements in one, two or even three dimensions.

Since the discovery of the Y-Ba-Cu-O superconductors, their physical properties have been investigated by various methods. The chemical state of Cu in Y-Ba-Cu-O compounds la one of the greatest issues because the mechanism of superconductivity in Y-Ba-Cu-O is not understood theoretically. We are analyzing X-ray fluorescence spectra of Cu compounds including superconductors, intending to analyze the chemical state of Cu in Y-Ba-Cu-O. As for other 3d transition elements, structures due to unpaired electrons appear clearly on the lower energy side of the Kα1 line of the element. However there are little differences observed among Cu Kα spectra of Cu compounds even if they are measured by a high-resolution two-crystal spectrometer (see Fig. 1). Although Cu is a member of 3d transition elements, its Kα spectrum shows somewhat different behavior compared with other 3d transition elements. This point is one subject we are interested in.

Recently synchrotron radiation (SR) sources have been extensively used for the study of materials science. The high intensity of tunable monochromatic X-rays from SR facilitates many types of spectroscopic/ diffraction studies which have otherwise not been possible. Regarding the X-ray fluorescence technique, significant improvement of the minimum detection limit has been performed and has enabled trace element analysis in the order of tens of ppb or 10-12 g.3-8 SR microanalyzers and near surface analysis using grazing incidence geometry are also attractive applications of synchrotron X-ray fluorescence technique. From a point of materials characterization, chemical state analysis is not less important than ordinary element analysis.

High resolution x-ray emission spectroscopy (HRXES) has been used to record the Si Kβ spectra of a variety of minerals. Distinct changes in peak profile can be related to mineral typo. Representatives spectra were chosen and incorporated, into a computer programme to allow the determination of free silica in binary and quaternary mixtures. The potential of HRXES for the analysis of airborne dust samples is discussed.

Recently, layered structure analyzers (called LSA for short) or layered synthetic microstructures (called LSM) with d spacing of several tens of Å, have been developed for use as X-ray analyzing devices in wave-length dispersive spectrometers. The lower detection limit for light elements of atomic numbers lower than 13 , such as aluminum, sodium, fluorine, oxygen, carbon and so on, has been greatly improved.

There have been several reports published regarding LSA (or LSM) applications to light element analyses.

Following an international interlaboratory comparison study of SL-3 Lake Sediment sample, the results showed a large range of values for the iron concentration (0.538 to 1.270% Fe) with an overall standard deviation of 18 percent from 38 accepted laboratory averages, see Figure 1 (1).

Various kinds of compounds containing arsenic have been used in the world as rat poisons, agricultural chemicals and so on. In the field of semiconductor materials, AsH3 is used as a doping gas on silieon-wafer substrates and GaAs is now also investigated as a wafer substrate instead of Si wafer.

As for quantitative analysis of arsenic, atomic absorption spectrometry (AAS) and inductively coupled plasma atomic-emission spectrometry (ICP-AES) have often been used. In these methods, usually, oomplioated pretreatments such as preconcentration and separation have been needed in order to obtain reproducible values for arsenic.

High purity of silicon wafers is demanded by the high performance and highly integrated IC and LSI semiconductors. Impurities on, or in, the silicon wafer have a big influence on the characteristics of the semiconductor as a final product. Usually, these impurities are introduced by water during washing, by bad handling, or by reagents and processes.

Typical influences of these impurities are shown in Table 1. These elements are present at too small concentration to he detected by ordinary analytical methods (except for oxygen). Usually, XPS , AES, NAA, SIMS, ICPAES, ICP-MS and AAS are used for trace analysis.

Total-reflection X-ray fluorescence spectrometry, abbreviated as TXRF, is known for its high sensitivity down to the low pg-level or sub-ppb level, respectively, and its wide dynamic range of about three to four orders of magnitude (Yoneda and Horiuchi, 1971, Wobrauschek and Aiginger, 1980; Knoth and Schwenke, 1978 and 1980, Aiginger and Wobrausohek, 1985, Michaelis et al., 1985, Prange, 1987). Meanwhile several laboratories have purchased commercially available TXRF spectrometers and have started to report favourable about this technique. Applications have been reported from various disciplines: These are estuarine and marine water quality management and research, air pollution studies, mineralogical investigations, biology and medicine (Prange, 1987, Prange et al, 1985; Prange and Kremling, 1985, Prange et al., 1987, Stöβel and Prange, 1985, Michaelis, 1986, Ketelsen and Knöchel, 1985, Leland et al., 1987, von Bohlen et al., 1987, Junge et al., 1983, Hentschke et al., 1985, Hentschke et al., 1985, Gerwinski and Goetz, 1987, von Bohlen et al., 1987), In spite of its close kinship to conventional EDXRF , TXRF is quite different with respect to operation and performance and provides complementary capabilities.

Various sample preparation methods for Energy Dispersive X-ray Fluorescence (EDXRF) analysis of Portland cement were compared in order to evaluate improvement in analytical accuracy and precision. Sample preparation requirements for EDXRF are slightly different than for Wavelength Dispersive X-ray Fluorescence (WDXRF), and the methods commonly used in WDXRF are not optimized for EDXRF. Primarily, the work focuses on techniques for producing a fused sample with the lowest practical concentration of lithium borate flux. Determination of minimum detection limits were made from samples with varying proportions of flux in order to evaluate analytical optimization. Ease and reproducibility of preparation of the sample was also considered.

Commercial interest in gold is persistent and resurgent, and there is a consequent need for reappraisal of its methods of analysis. Because its modes of occurrence often manifest themselves in irregular dispersion and low concentration, special care must be taken in sampling and analysis. A sufficient amount of the initial sample must be taken to ensure adequate representation, and preconcentration is often necessary to elevate the metal content to a confidence level high enough above the detection limit for the analytical technique.

A new apparatus and technique are described for borate flux fusion of rocks for x-ray fluorescence analysis. The method yields homogeneous, strain-free glass discs with flat, smooth surfaces that do not require polishing. The technique is adapted from several previous methods but has advantages over each in terms of sample uniformity, quality of the discs, or capital cost. The ignited rock powder is fused with flux over a burner mounted on a stock laboratory mixer, and is cast into a solid flat, polished Pt-Au mold. The very effective mixing action ensures homogeneity An oxidizing atmosphere, which is necessary to prevent loss of iron to the crucibles, is maintained by injecting air during fusion.

There is no significant loss of alkali metals during fusion, and negligible loss of flux. Duplicate samples of several rock types show excellent reproducibility, approaching counting statistical errors, for 10 major elements.

The combination of an improved resolution, gas proportional detector with advanced microprocessor technology provides a new and unique solution to the problem of alloy analysis.

A field portable, microprocessor controlled, fully user-programmable x-ray analyser is described for fast, reliable, on-site, positive alloy identification and assay. The radio-isotope based analyser employs a modified Lueas-Tooth and Price model of intensity corrections for quantitative, multielement analysis. Applications are reviewed and include examples to show the superior performance of the instrument in such difficult eases as sulfur in carbon steels, and titanium and nickel in stainless steels.

Discussion of the unique alloy identification scheme and its underlying principles is followed by examples of applications illustrating the capabilities of the instrument in distinguishing, in 5 seconds, alloys of closely similar compositions such as stainless steels 303, 304 and 321, and 410 and 416.

A special measurement technique has been developed to measure very low level iodine concentrations. The gas and water samples to be analysed are taken from the POSEIDON facility at PSI where retention of iodine in water pools in conjunction with light water reactor safety analysis is under investigation. The amount of iodine was measured by means of a Total Reflectance X-Ray Spectrometer (TXRF).

Recently, a new radioisotope X-ray fluorescence technique was reported in which a small quantity (100μCi) of a selected radioisotope was directly mixed with a small amount of the sample, as a source-sample. Many different types of excitation radiation from various radioisotopes have been previously studied: Na-22, S-35, Fe-55, Co-57, Hi-63, Zn-65, Cd-109, 1-125, Cs-137, Pa-147 and Ara-241.

Recently variable sample exit-angle x-ray fluorescence spectrometry (VEA-XRF) has been shorn to be a useful analytical tool for monitoring the oxidation of the surfaces of bulk Cu, Ni as well as that of Fe. In these studies advantage was taken of the well known phenomenon that for each transition metal oxide (MO) Lβ/Lα intensity ratio value is higher than for the transition metal (M), itself. Within the limits of the photon-escape depth de, which for these photons are generally below 5000 Å, varying the sample exit-angle θ offers an opportunity for seeing whether or not the oxidation of the surfaces of bulk M belongs to one of the following two classes: (I) uniform oxidation throughout the entire observable sample-depth, (II) preferential oxidation of the top surface layer, i.e. depth dependent oxidation.

X-ray diffraction techniques have been used for the structure characterization of Y-Ba-Cu-O and Tl-Ca-Ba-Cu-O thin films. A powder diffraction analysis of Y-Ba-Cu-O films showed that the films deposited at 650°C on Si are polycrystalline and have an orthorhambic structure similar to that of the YBa2Cu3O7 bulk superconductors. In addition to the conventional powder diffraction technique, both the rocking curve and the grazing incidence diffraction methods were used to characterize a YBa2Cu3O7 film on (110) SrTiO3 substrate. Results showed that the film was epitaxially grown and aligned with its substrate in a true epitaxy. Phase identification and line broadening analyses of Tl-Ca-Ba-Cu-O films showed that the films are comprised of one or more superconducting phases and probably contain stacking faults.

A method was described for determining the thickness of epitaxical thin films common to electronic materials. The equations were developed based on the kinematical theory of X-ray diffraction and effects of both primary and secondary extinctions were considered. As an example of the applications of this method, thickness measurement of AlGaAs thin films on GaAs was demonstrated. These films were grown by molecular beam epitaxy. The integrated reflected intensities from the film and the substrate were obtained by the X-ray double crystal diffractometer. An excellent agreement was obtained between the results from X-ray measurements and RHEED oscillation data.

It is necessary to know the orientation of thin surface layers for the electronic industry as well as for different studies on interphases (epitaxy, topotaxy, phase transformation, reactivity of solids).

It is difficult to obtain information with a conventional Schulz goniometer (Bragg-Brentano geometry) because of the insufficient amount of diffracting material.