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X-Ray Studies of Liquid Interfaces in Model Solvent Extraction Systems
Published in Bruce A. Moyer, Ion Exchange and Solvent Extraction: Volume 23, 2019
X-ray reflectivity measurements are analyzed by fitting them to a model of the electron-density profile ρ(z), which is typically a set of interfacial layers characterized by the electron density and thickness of each layer. This type of analysis yields an electron-density profile (perpendicular to the interface) with sub-nanometer spatial resolution and ±2% or better uncertainties in the electron density.26,54 The electron-density profile is then interpreted to yield the interfacial molecular arrangement.40,41, 43–47,55
X-Ray Methods
Published in Grinberg Nelu, Rodriguez Sonia, Ewing’s Analytical Instrumentation Handbook, Fourth Edition, 2019
The techniques that are encompassed by this phenomenon are total X-ray re flection fluorescence (TXRF), X-ray specular reflectivity, and X-ray diffuse scattering. X-ray reflectivity takes advantage of the fact that when X-rays are directed at a sample at an angle lower than the critical angle, virtually all photons will be reflected at an equally small angle. The few X-rays directed at the surface will excite atoms close to the surface, which in turn will emit their characteristic radiation in all directions with virtually no backscatter.
Materials Characterization Using Advanced Synchrotron Radiation Techniques for Antimicrobial Materials
Published in Peerawatt Nunthavarawong, Sanjay Mavinkere Rangappa, Suchart Siengchin, Mathew Thoppil-Mathew, Antimicrobial and Antiviral Materials, 2022
Chatree Saiyasombat, Prae Cbirawatkul, Suittipong Wannapaiboon, Catleya Rojviriya, Siriwat Soontaranon, Nuntaporn Kamonsutthipaijit, Sirinart Chio-Srichan, Chanan Euaruksakul, Nichada Jearanaikoon
X-ray reflectivity (XRR) is a non-destructive method for investigating properties of single or multilayered thin films. XRR is used to determine the thickness, density, and surface or interface roughness of exciting layers. This technique is based on measuring total reflection intensity as a function of incident angles concerning the thin him surface. Single-crystalline, polycrystalline, or amorphous materials can be non-destructively analyzed.
Structural and magnetic properties of CoTi thin films deposited by magnetron sputtering method
Published in Phase Transitions, 2021
Maheswari Mohanta, S. K. Parida, Ananya Sahoo, Mukul Gupta, V.R.R. Medicherla
Figure 1(a) represents the Grazing Incidence X-ray Diffraction patterns of CoTi thin films recorded using CuKα radiation (λ = 1.514 Å). The presence of a sharp peak at 40.3° scattering angle in Co0.7Ti0.3 thin film, suggesting the formation of hcp (MgNi2 type) structure with lattice constants a = b = 2.656 Å and c = 4.069 Å whereas Co0.5Ti0.5 and Co0.3Ti0.7 surface thin films have cubic (MgCu2 type) structure with lattice constant 3.162 and 3.21 Å respectively. The interplanar spacings of the cubic structure are indeed very close to some of the spacing of hexagonal. The influence of the impurities, the thickness of the films and particle size may be suggested as an explanation for the existence of a cubic structure [18–21]. The average crystallite size of the hcp Co0.7Ti0.3 thin film using Scherer’s formula is found to be 2.83 nm whereas the average crystallite size of the cubic Co0.5Ti0.5 and Co0.3Ti0.7 thin films is 2.24 and 1.82 nm respectively [22]. GI-XRD results indicate that the average crystallite size of x = 0.5 and 0.7 thin films are smaller than at x = 0.3 surface alloys. Figure 1(b), (c), and (d) represent the X-ray reflectivity patterns of Co0.7Ti0.3, Co0.5Ti0.5 and Co0.3Ti0.7 thin films respectively. This technique is very accurate to measure thickness of the film from 1 to 35 nm. X-ray reflectivity depends on electron density in the material. Intensity modulation in X-ray reflectivity depends on the thickness of the film. Substrate will not contribute to intensity modulation as the X-ray entered in the substrate will not get reflected. The experimental XRR data were fitted numerically using Parratt formalism [23] and the results reveal that the thickness of the Co0.7Ti0.3, Co0.5Ti0.5, and Co0.3Ti0.7 thin films is around 30 nm (Table 1).