Glancing angle

Brunei M 1995 Glancing angle x-ray diffraction Encyciopedia of Anaiyticai Science vol 8, ed A Townshend (London Academic) 8 4922-30... 

Reflection and refraction of X-rays follow the laws of optics (Fig. 4.2) The glancing angles of incidence (i) and reflection ( ) are equal. The respective refraction angles follow Snell s law for different phase velocities v in mediums 1 and 2 ... 

Fig. 4.3. Signal intensity of a thick, flat, and smooth Si-sub-strate (-), calculated for an impinging Mo-Ka beam. The reflectivity R ( ) is shown it depends on the glancing angle f. Below d>c = 0.102°, total reflection occurs with a stepwise increase in reflectivity and a stepwise decrease in signal intensity. The oblique dashed line represents the intensity from a rough Si substrate [4.21],...

Fig. 4.4. Penetration depth z ofX-rays striking silicon at a variable glancing angle d>i. The curves were calculated for three different photon energies. The dashed vertical line signifies the respective critical angle [4.21],...

The bulk type response curve depends also on surface roughness [4.34]. Reference materials must, therefore, be carefully investigated by angle-scan before use. Angle-scan characteristics of the sample, i.e. the fluorescence intensity recorded at more than one glancing angle near (j>, should not deviate from those of the reference. The measurement must be performed under similar optical conditions. 

Fig. 4.10. Fluorescence signal from small particles or thin films deposited on a silicon substrate used as sample carrier. The intensity was calculated for particles, thin films, or sections ofdiffe-rent thickness but equal mass of analyte, and plotted against the glancing angle f. A Mo-Ka beam was assumed for excitation. Particles or films more than 100 nm thick show double intensity below the critical angle of0.1° [4.21].

Fig. 4.14. Fluorescence intensity from layers buried in a thick substrate. The dependence of intensity on the glancing angle was calculated for layers of different thickness but with a constant analyte area density. Silicon was assumed as substrate and Mo-Ka X-rays as primary beam. Total reflection occurs in the region below 0.1°. Without total reflection, the dashed horizontal line would be valid throughout [4.21].

GIAB studies of sputtered thin films of different composition for tribological applications have been reported [4.157-4.159]. The technique has been used to study the structure of very thin GdS layers (deposited by chemical bath deposition) for photovoltaic applications in combination with 6-26 diffraction it enabled identification of their polytype structure [4.160]. Glancing angle diffraction in the GIAB geometry... 

Glam-weiss, n, brilliant white talo. -wichse, /. polishing wax. -winkel, m. glancing angle. 

Reflex type Relative intensity Diffraction indices (hkl) Interplanar spacing d/, / (A) Glancing angle for CuK -2Q/, ( )... 

Fig. 8. X-ray reflection diagram of a thin polystyrene film on float glass [160]. The reflectivity R is plotted against the glancing angle . The film is spin coated from solution. A model fit (dashed line) to the reflectivity data is also shown where the following parameters are obtained film thickness = 59.1 0.1 nm, interface roughness glass-polymer = 0.4 0.1 nm, surface roughness polymer-air = 0.6+1 nm, mean polymer density = 1.05 + 0.01 g/cm-3. The X-ray wavelength is 0.154nm...

EDXRF vs. WDXRF, sequential vs. simultaneous XRF), geometry (TXRF, SEXAFS, glancing angle), theoretical interpretations (EXAFS, XANES), microanalysis ( xXRF, EPMA), hyphenation or on-line analysis. There is sufficient scope for polymer/additive analysis by means of XRS tools. 

A naturally occurring chiral metal structure is a screw dislocation (Fig. 3.4),11 which is a chiral arrangement observed in metal crystals but never resolved and tested for enantioselective heterogeneous catalysis. A possible method of making chiral arrangements like screw dislocations is by the glancing angle deposition technique, which can produce chiral sculptured thin films.12... 

A common hazard in the handling of explosives is for them to be subjected to the effects of a blow which is to some extent at a glancing angle. This corresponds neither to pure impact, nor to pure friction. A corresponding simple and useful test for the safety of an explosive during handling is the torpedo friction test illustrated in Fig. 6.8. In this, a torpedo... 

Fig. 24. Glancing angle XRD pattern of a 270 cycle deposit of InAs. Adapted from ref. [280],...

---