Die tertiäranregung in der quantitativen röntgenfluoreszenzanalyse

The theory of tertiary excitation of characteristic X-rays is treated. A computer evaluation of the equations shows for the ternary system Cr-Fe-Ni a contribution of 3 per cent at maximum to Cr-K-radiation, which can be excited tertiary. Of course it is also excited secondary by Fe- and Ni-radiation, but this influence has been discussed in an earlier paper [1].     

Analyse dünner schichten von tetramethylendithiocarbamidaten auf metalloberflächen mittels f.m.i.r.-spektroskopie im infraroten bereich

The possibilities and limitations of the application of frustrated multiple internal reflectance spectroscopy in the mid-infrared region for the analysis of organic corrosion products are described. As model substances, the tetramethylenedithiocarbamates of Fe, Ni, Cu, Zn, Cd and Pb, prepared as thin layers on the corresponding metal sheets in a simulated corrosion process, have been investigated. Chelate layers down to a thickness of 10 nm can be analyzed with 45° Ge internal reflection plates (25 reflections).     

Röntgenographische Hochtemperaturuntersuchung der Thermischen Zersetzung von Dodekawolframatoborsäure

Investigation on the Thermal Degradation of 12-Tungstoboric Acid by Means of X-ray Heating Photographs By means of X-ray Guinier investigation of 12-tungstoboric acid hexahydrate H₅[BO₄W₁₂O₁₂] · 6H₂O at room temperature a monoclinic lattice was determined, being in disagreement with the literature. The LSQ-refinement of parameters of the monoclinic C-lattice give a = 1.728 nm, b = 1.215 nm, c = 1.216 nm, b? = 135° 34′, Z = 2, d_exp. = 5.44 g cm^?3, d_calcd. = 5.52 g cm ^?3. From X-ray heating patterns (heating rate: 4°C/min, atmosphere: air) the formation of a new monoclinic phase at 185°C was found, being stable till 270°C. From 270–420°C exist a bad crystalline phase and from 420–840°C a monoclinic phase: a = 0.532 nm, b = 0.389 nm, c = 0.522 nm, b? = 91° 09′. Above 840°C a tetragonal phase is formed with a diagram typical for pure WO₃. The relationship between the modifications is discussed.     

Über den Einfluss der Sekundäranregung und der Streuung auf die Röntgenfluoreszenzintensitäten bei der Lösungs-RFA

For solution techniques, X-ray fluorescence intensities are-besides primary excitation-primarily influenced by scattering processes, and on a small rate by secondary excitation when compared with scattering. An increase of solved matter causes an increase of the secondary contribution and a decreasing scattering influence. This should be taken into account for selecting reference solution concentrations as well as for considering the accuracy of the method.