X-ray refractive index: A tool to determine the average composition in multilayer structures
We present a novel and simple method to determine the average composition of multilayers and superlattices by measuring the x-ray refractive index. Since these modulated structures exhibit Bragg reflections at small angles, by using a triple axis x-ray spectrometer we have accurately determined the peak shifts due to refraction in GaAs/Al/sub x/Ga/sub 1-x/As and Nb/Ta superlattices. Knowledge of the refractive index provides the average fractional composition of the periodic structure since the refractive index is a superposition of the refractive indices of the atomic constituents. We also present a critical discussion of the method and compare the values of the average fractional composition obtained in this manner to the values obtained from the lattice parameter change in the GaAs/Al/sub x/Ga/sub 1-x/As superlattices due to the Al.
- Research Organization:
- Department of Physics and Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
- DOE Contract Number:
- AC02-76ER01198
- OSTI ID:
- 6406865
- Journal Information:
- Appl. Phys. Lett.; (United States), Vol. 48:1
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ALUMINIUM ARSENIDES
BRAGG REFLECTION
CHEMICAL COMPOSITION
REFRACTIVITY
GALLIUM ARSENIDES
LAYERS
NIOBIUM
MEASURING METHODS
X RADIATION
SUPERLATTICES
TANTALUM
X-RAY DIFFRACTION
X-RAY SPECTROMETERS
X-RAY SPECTROSCOPY
ALUMINIUM COMPOUNDS
ARSENIC COMPOUNDS
ARSENIDES
COHERENT SCATTERING
DIFFRACTION
ELECTROMAGNETIC RADIATION
ELEMENTS
GALLIUM COMPOUNDS
IONIZING RADIATIONS
MEASURING INSTRUMENTS
METALS
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
PNICTIDES
RADIATIONS
REFLECTION
SCATTERING
SPECTROMETERS
SPECTROSCOPY
TRANSITION ELEMENTS
360603* - Materials- Properties
360104 - Metals & Alloys- Physical Properties