X-ray Reflectometry and Related Surface Near X-ray Scattering Methods

AbstractSurface sensitive X-ray scattering methods are mostly non-destructive tools which are frequently used to investigate the nature of thin films, interfaces and artificial near surface structures. Discussed here are diffraction based methods, namely reflectometry and the related techniques grazing incidence diffraction and crystal truncation rod measurements. For the experiment, an X-ray beam is diffracted from surface near structures of the sample and detected by adequate detectors. To analyze the data the according X-ray scattering theory has to be applied. The full theory of surface sensitive X-ray scattering is complex and based on general considerations from wave optics. However, instructive insights into the scattering processes are provided by the Born-approximation which in many cases yields sufficient results. The methods are applied to solve the structure of a mercury-electrolyte interface during a chemical reaction and to determine the strain distribution in surface near SiGe quantum dots.

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Strain Analysis in Thin La1−xCaxMnO3 Films by Grazing Incidence X-ray Scattering

MRS Proceedings ◽

10.1557/proc-602-195 ◽

1999 ◽

Vol 602 ◽

Author(s):

M. Petit ◽

L. J. Martinez-Miranda ◽

M. Rajeswari ◽

A. Biswas ◽

D. J. Kang ◽

...

Keyword(s):

Film Thickness ◽

Lattice Mismatch ◽

Compressive Strain ◽

Strain Analysis ◽

Grazing Incidence ◽

Relaxation Processes ◽

Near Surface ◽

X Ray ◽

X Ray Scattering ◽

Ray Scattering

AbstractWe have performed depth profile analyses of the lattice parameters in epitaxial thin films of La1−xCaxMno3 (LCMO), where x = 0.33 or 0.3, to understand the evolution of strain relaxation processes in these materials. The analyses were done using Grazing Incidence X-ray Scattering (GIXS) on films of different thicnesses on two different substrates, (100) oriented LaAlO3 (LAO), with a lattice mismatch of ∼2% and (110) oriented NGO, with a lattice mismatch of less than 0.1%. Films grown on LAO can exhibit up to three in-plane strained lattice constants, corresponding to a slight orthorhombic distortion of the crystal, as well as near-surface and columnar lattice relaxation. As a function of film thickness, a crossover from a strained film to a mixture of strained and relaxed regions in the film occurs in the range of 700 Å. The structural evolution at this thickness coincides with a change in the resistivity curve near the metalinsulator transition. The in-plane compressive strain has a range of 0.2 – 1.5%, depending on the film thickness for filsm in the range of 400 - 1500 A.

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X-ray Scattering Studies of Maquette Peptide Monolayers. 1. Reflectivity and Grazing Incidence Diffraction at the Air/Water Interface

Langmuir ◽

10.1021/la000264z ◽

2000 ◽

Vol 16 (26) ◽

pp. 10404-10418 ◽

Cited By ~ 12

Author(s):

Joseph Strzalka ◽

Xiaoxi Chen ◽

Christopher C. Moser ◽

P. Leslie Dutton ◽

Benjamin M. Ocko ◽

...

Keyword(s):

Grazing Incidence ◽

Water Interface ◽

X Ray ◽

X Ray Scattering ◽

Grazing Incidence Diffraction ◽

Air Water Interface ◽

Ray Scattering

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Morphology of nanostructured materials

Pure and Applied Chemistry ◽

10.1351/pac200274091553 ◽

2002 ◽

Vol 74 (9) ◽

pp. 1553-1570 ◽

Cited By ~ 24

Author(s):

M. K. Sanyal ◽

A. Datta ◽

S. Hazra

Keyword(s):

Thin Films ◽

Nanostructured Materials ◽

Small Angle ◽

Grazing Incidence ◽

Bulk Properties ◽

X Ray ◽

X Ray Scattering ◽

Grazing Incidence Diffraction ◽

Ray Scattering

Here we shall discuss the importance of grazing incidence X-ray scattering techniques in studying morphology of nanostructured materials confined in thin films and multilayers. In these studies, the shapes, sizes, and structures of nanostructured materials and their distribution in composites are investigated. These studies are important for understanding properties that may deviate considerably from the known bulk properties. We shall first outline basics of three X-ray scattering techniques, namely X-ray reflectivity, grazing incidence small-angle X-ray scattering, and grazing incidence diffraction, used for these studies. We shall then demonstrate the utility of these techniques using some known results.

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