The mass absorption coefficient (μ) of a weakly absorbing solid material may be measured by either the transmission or the reflection method. The latter typically employs a crystalline substrate and the diffraction method, measuring the transmission of the diffraction peak(s) of the substrate through the analyte. Compressing or compacting a powdered sample is not required when the reflection method is used.

The electroplating of Cr has been an important industrial process for cutting tools, press machines and molds for casting. In spite of these, quite a few problems remain unsolved regarding the basic property. It is important to know the mechanical characteristics of Cr electroplated layers.

In the present paper, the first part deals with the measurement of mechanical Young's modulus of Cr electroplated layers. The X-ray method was successfully applied to measure the X-ray Young's modulus and the residual stress on the Cr electroplated surface layer.

The LIII x-ray emission bands from some 3d transition metal oxides and the K emission bands from some second and third period metal oxides and nitrides are shown and discussed in relation to the energy band structure of these compounds. It is demonstrated that the LIII emission bands can be grossly distorted by excitation conditions. Many of the compound spectra show strong evidence of a crossover transition which originates in the anion and terminates in the metal ion. For the 3d compounds this crossover transition appears to be related to the elsctrical and magnetic properties. In oxides of some second and third period elements it appears that the crossover transitions are responsible for the entire K band spectrum.

An updated d, I-MATCH procedure [Frevel and Adams, Anal. Chem., 40, 1335-1340 (1968)] is described which permits analysts to compare diverse powder-patterns in a quantitative,objective manner. Criteria are established for rating the quality of a diffraction standard. The d, I-MATCH program has been combined with an efficient SEARCH program to facilitate the quantitative matching of multiphase powder patterns.

During the past several years, a number of analyzing crystals have been prepared in the U.S. Air Force Aerospace Research Laboratories. Crystals such as alkaline acid malonates, sucrose, pentaerythritol (PET), and several others have been grown with the sole purpose of application in X-ray fluorescence analysis of silicon, aluminum, and other elements of low atomic number. Crystals from natural sources, such as quartz, mica, and gypsum, have also been procured from different parts of the world for this purpose.

Among the analyzing crystals so prepared, pentaerythritol gave the highest count rate for silicon and aluminum. However, since this crystal is organic in nature, great care must be exercised in handling this type of crystal in order to obtain constant count rates. For the analysis of silicon and aluminum, a-quartz crystal gave a somewhat low count rate, but this crystal has certain advantages over the organic crystals, and can be used for analysis of materials having high silicon and aluminum content.

For instance, when using a conventional X-ray emission vacuum spectrograph of standard make, with the latest alterations, one of the PET crystals attained a count rate of 101,870 cps for pure silicon when the instrument was operated at 60 kVP and SO m A with a negligible background count. With a constant potential attachment and operated at 60 kVP and 34 mA, 1.15,600 cps with negligible background count was obtained for silicon. The count rate for aluminum was of the same order of magnitude with somewhat higher background count.

Several sets of standards have been procured and small amounts of silicon and aluminum in these standards have been analyzed by the latest modified vacuum spectrograph. These results are under study and the limit of detection calculated. Procedures and results are described and discussed.

Self-scanning photodiode arrays were tested for their ability to measure the spatial distribution of low-energy x rays in a wavelength dispersive spectrometer. X-ray spectral sensitivity was measured with a calibrated de source of nearly-monochromatic characteristic-x rays with photon energies in the range of 1.5 to 8 keV. Photodiode response was found to be linear with x-ray flux. Exposure to large doses of copper radiation did not effect sensitivity. A mathematical model that describes the experimental data is presented. We found that spatial resolving power was lowered by the dispersal of photogenerated charges. This effect was investigated with collimated beams and is described with a formula that predicts the loss of diode signals.

Different procedures used in precision measurements of lattice parameters are, strictly, only valid if they can be shown to give results that are mutually reproducible. For this purpose reproducibility is defined in terms of the parameters a. and standard deviations a. obtained for X-ray specimens of one or more reference materials. The requirement is that all systematic errors should be minimized to a level below that of the random measurement errors. Where these have a Gaussian distribution the significance of the difference, Δa°, between two , measurements can then be Let;Led by evaluating . Thus, if K < 2 the difference, Δa°, cannot be distinguished from the effects of random measurement errors. This condition should be met for specimens of the same sample if reproducibility is good. For K ≥ 3 the value of Δa° is then taken to reflect real differences in the crystalline Jattice of two X-ray specimens of a given compound. A basis is thus created for the study of solid solubility and for the precise characterization of crystalline compounds.

X-ray diffraction topography is the name given to several x-ray diffraction techniques where large area x-ray beams diffracted from a crystal provide detailed information about the surface structure and internal perfection of crystal microstructures. Since x-ray topographic techniques are based on Bragg (reflection) or Laue (transmission) diffraction from a crystal lattice, they are extremely sensitive to any atomic lattice imperfections and strains. Alterations of the interplanar spacing as small as one part in ten thousand extending over a reasonable number of atomic ce11 lengths can be recorded as a corresponding change in the diffracted beam intensity. Line Modified-Asymmetric Crystal Topography (LM-ACT) is one such reflection technique that shows particular promise in Che field of microelectronics. The LM-ACT system is designed with low angular divergence in the x-ray beam probe. Low probe beam divergence allows details of device geometries on the order of microns to be resolved in the recorded x-ray intensity variation of the diffracted beam.

The LM-ACT system was applied here to the study of integrated circuits (IC) after specific processing steps were accomplished during IC fabrication and in the final product condition. Topographs obtained from specular crystal surfaces that were implanted through a patterned mask showed contrast variations between the implanted and non-implanted regions; details of the mask patterns have been resolved on the order of a few microns. LMACT topographs from annealed, and unannealed, Implanted specimens showed marked differences and as a result it is suggested that LM-ACT would be beneficial in optimizing the processing schedule for a particular wafer/electronic system. A significant feature of the LM-ACT technique is the capability for producing high resolution stereo-pair topographs that provide quantitative information through the depth of individual process layers in an integrated circuit.

The introduction of various atoms into crystal surfaces by ion implantation has become common practice in the research laboratory and in many industrial processes. The deceleration of the introduced foreign ions during implantation results in extensive lattice damage. Atom displacement from equilibrium crystal sites and pile-up of the new atoms take place. The use of the pulsed laser for annealing these atomic defects in a single crystal is well documented . The absorption of the total energy in the laser pulse can be rapidly transferred to the lattice, approximately 10-9s, for an elevated temperature anneal of the damaged crystal. The photon energy of the monochromatic laser beam can be tailored so that the absorption of the radiation by a specific crystal can “be matched for its penetration into the crystal to that of the depth of the implanted atoms. A highly efficient mechanism is thus utilized to anneal just that portion of the crystal which is damaged by the impinging atoms of the implant.

Energy dispersive X-ray spectrometry has the potential for making very rapid analyses of multi-element samples. In order to fully exploit this capability several studies have been carried out with the goal of improving performance at high input count rates. A refined amplifier permits operation at input count rates up to 80000 per second with minimal peak shift and distortion. Optimum choice of tube parameters and filters permits utilization of a single Mo transmission target tube to analyze a broad range of elements in minimum time. Use of a pulsed tube further reduces the time required for analysis without sacrifice of precision or resolution. Dead time necessarily increases with increasing input count rate. It can be reduced by selecting a short amplifier time constant, but only with a loss of resolution. Digital processing permits recovery of the lost resolution. Some illustrations are given of spectra that have been processed on-line using a computer based multi-channel analyzer.

In modern technology, thin-layered materials with layer thickness in nanometer ranges have been utilized for various advanced components such as integrated circuits, magnetic heads and disks, X-ray mirrors and coated window glasses. For the analysis of such materials, powerful probes, fluorescence(TXRF)1), diffraction(TXRD) 2-4) and reflectivity(GIXR) 5-7), formed by X-rays in conjunction with total reflection phenomena can provide important information on element composition, crystalline structure, layer thickness, electron density and interfacial roughness.

Nowadays x-ray fluorescence analysis is one of the major techniques for determination of trace elements. Vacuum operated Si (Li) .energy-dispersive x-ray spectrometers can analyze simultaneously up to 50 elements from Na (Z=11) to U (Z = 92) . Proper interpretation of the accumulated spectra requires correct solution of x-ray line overlap problems. In many cases knowledge of x-ray intensity ratios can make the procedure for resolving the overlapped peaks more reliable and reproducible. Measurements of radiative transition rates can also provide fundamental tests of theoretical atomic structure calculations. There are many other useful applications of x-ray emission rates in theoretical and experimental physics. On the other hand, there are differences in the published data, which suggests that x-ray intensity ratios are still not known with the necessary accuracy, and new measurements are useful and necessary.

In order to study the effects of processing variables on the defect contents of silicon wafers, an X-ray extinction contrast camera was designed and constructed to fit on the standard GE XRD-5 table. The camera, in its normal operating position, can be routinely used without interfering with the emission or diffraction instrumentation of the unit, and also can be mounted on the diffractometer stage for diffraction line breadth analysis. Routine laboratory procedures including sample preparation and mounting, film types, and film exposure and development are outlined.

The correlation between extinction contrast topographs and optical photographs of sawed wafers is presented. Wafers were examined in the sawed, lapped, and chemically polished conditions. Subsequent to each processing step in the surface treatment of wafers, a series of topographs was made using four different crystal orientations. In this manner the three-dimensional picture of the defects is obtained, as are the Burger's vectors of all dislocations. It appears that internal defects such as dislocations are more uniformly distributed in lapped and chemically polished wafers than in sawed and chemically polished wafers. Furthermore, different doping impurities and levels cause different amounts of contrast in the dislocation images.

The Rietveld method entails the calculation of a powder diffraction pattern from crystallographic, microstructural and equipment characteristics. These characteristics are related to the form of the pattern through a series of model functions. The difference between an observed and calculated pattern is then minimized by sequentially refining the physical parameters contained within the mode) functions to obtain an accurate and precise description of the specimen. A powder diffraction pattern from a specimen exhibiting cry stallo graphic texture, or preferred orientation, will display intensity values which differ systematically from those calculated for a specimen of random orientation. This systematic discrepancy can be addressed by incorporating into the Rietveld refinement a model function for sample texture. A successful model for texture will accurately assess the phase abundance and degree of texture from both oriented and randomized specimens. In this study we use the March-Dollase model function to characterize texture development in sintered alumina with respect to processing variables and sintering time.

This paper describes the detailed assembly of an X-ray automatic analyzer for the continuous estimation of elemental contents in flowing pulp streams as applied in a concentrator of the Northern Rhodesian Copperbelt. Arguments are given for the selection of electronic components, the programming of operations, mechanical movements, and other aspects concerned with the consecutive analysis of a number of pulp streams of widely different composition and elemental concentration. Details are given of a method of automatic compensation for pulp density and matrix variations using X-ray absorption.

In nuclear power plants the fast neutron fluence on the pressure vessel (PV) inner wall is measured by the scraping sampling method (1). As the inner plating of the pressure vessel contains 0.5 - 0.6 % of niobium, 93mNb (tt/2 = 16a) isomer is produced by the reaction 93Nb (n, n’). The activity of 93mNb is related to the fast neutron fluence.

Scraping samples (few hundred of mg) were taken from the PV inner wall. The niobium was chemically extracted from steel by using a HAP column. This extraction was needed to reduce matrix effects and to avoid interferences of other activities with 93mNb

Techniques of mineral analysis by fluorescent X-ray spectrography can generally be classified on the basis of (1) extensive sample preparation and simple instrumental examination, (2) simple sample preparation and extensive instrumental examination, (3) extensive processes for both, or (4) simple processes for both major phases of the technique. The latter type of technique is usually the most commensurate with the concept “maximum information with minimum effort.”

Suitable analytical results with multielement calibration systems for random mineral samples can be obtained if there are valid considerations of the relevant absorption and enhancement effects or if the systems are based on general procedures to minimize absorption and enhancement effects. Preliminary investigation indicated that control of sample mass and use of thin films of the mineral sample is a convenient and simple method of minimizing absorption and enhancement effects.

Successful application of thin-film samples with known masses in a multielement calibration system is highly dependent upon details of sample preparation and comprehensive studies of these details will be discussed.

The calibration system is suitable for the determination of minor and major concentrations in the sample, but it is not recommended for determination of trace concentrations.

A detailed analysis of the high angle diffuse scattering from small platelets is given. A large number of statistically centrosymmetric platelets is considered, and it is shown that, in this cage, the positive square root of the diffuse intensity from the platelets is proportional to the amplitude of the scattered radiation over particular regions in reciprocal space. The measured amplitude distribution is truncated from the true amplitude distribution by the limits of measurement and the influence of Bragg scattering. A truncation function is introduced to describe this truncated amplitude distribution in terms of the true amplitude distribution. This truncation introduces modulations on the measured electron density distribution. The measured electron density distribution is described in terms of the convolution of the true electron density distribution and the transform of the truncation function. The transform of the truncation function is knowi analytically, so the true electron density distribution can be found by a relaxation method. The true electron density distribution is given in terms of composition and strain parameters which are independently adjusted during the relaxation procedure to fit the measured values. Examples of the influence of the truncation function arc given and the technique is applied to G–P 1 zones in an aluminum - 1.67 at % copper alloy.

Over the past 25 years, numerous studies of polymers utilizing both X-ray diffraction (XRD) and differential scanning calorimetry (DSC) have been reported in the literature. These studies have suffered because the two techniques must be performed on separate samples and under conditions that are often dissimilar. By combining the two techniques into one instrument, typical problems encountered with variations in sample preparation and thermal and atmospheric environment are eliminated. This is quite important in the study of polymers since one must match not only temperatures between the two techniques, but also heating rates as well. Matched thermal conditions are necessary because polymer properties such as crystallinity and crystallite size depend on both the temperature and thermal history of the sample under study.