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Extended X-ray absorption fine structure
About: Extended X-ray absorption fine structure is a research topic. Over the lifetime, 10452 publications have been published within this topic receiving 276744 citations.
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TL;DR: In this article, a dense powder of nanocrystalline ZnO has been recovered at ambient conditions in the metastable cubic structure after a heat treatment at high pressure (15 GPa and 550 K).
Abstract: Dense powder of nanocrystalline ZnO has been recovered at ambient conditions in the metastable cubic structure after a heat treatment at high pressure (15 GPa and 550 K). Combined x-ray diffraction (XRD) and x-ray absorption spectroscopy (XAS) experiments have been performed to probe both long-range order and local crystallographic structure of the recovered sample. Within uncertainty of these techniques (about 5%), all the crystallites are found to adopt the NaCl structure. From the analysis of XRD and XAS spectra, the cell volume per chemical formula unit is found to be 19.57(1) and 19.60(3) A3, respectively, in very good agreement with the zero-pressure extrapolation of previously published high-pressure data.
82 citations
TL;DR: In this paper, a theoretical model of photothermal processes in the transverse (TPDS) experimental configuration is presented to determine the dependence of both signal channels on the optical absorption coefficient of the solid material and to define absorption coefficient ranges within which TPDS can be used as a spectroscopic technique.
Abstract: Information about the optical absorption coefficient of solid materials in contact with a fluid phase can be obtained from photothermal deflection (PDS) measurements using both the signal amplitude and phase channels of the PDS response of a system to an optical excitation. This paper presents a theoretical model of photothermal processes in the transverse (TPDS) experimental configuration. The theory is used to determine the dependence of both signal channels on the optical absorption coefficient of the solid material and to define absorption coefficient ranges within which TPDS can be used as a spectroscopic technique. A method concerning the use of the combined amplitude and phase data for the absolute measurement of the absorption coefficient is presented for the experimentally important thermally thick limit.
82 citations
TL;DR: In this article, it was shown that the optical absorption coefficient varies inversely with light intensity, and that if a monochromatic light beam absorbed by a semiconductor generates enough carriers to fill band states up to and including those of the optical transition, then the absorption will be saturated and a condition of transparency should result.
Abstract: If a monochromatic light beam absorbed by a semiconductor generates enough carriers to fill band states up to and including those of the optical transition, the optical absorption will be saturated and a condition of transparency should result. Analysis shows that in this regime the absorption coefficient varies inversely with light intensity.
82 citations
TL;DR: The role of Ag+ ions in the ultraviolet-driven photochemical synthesis of Au nanorods (NRs) in aqueous surfactant mixtures has been investigated in order to elucidate the mechanism that drives anisotropic nanoparticle growth as mentioned in this paper.
Abstract: The role of Ag+ ions in the ultraviolet-driven photochemical synthesis of Au nanorods (NRs) in aqueous surfactant mixtures has been investigated in order to elucidate the mechanism that drives anisotropic nanoparticle growth. The samples, grown in the presence of varying amounts of Ag+ ions for scheduled irradiation times, have been characterized by ultraviolet−visible−near infrared (UV−vis−NIR) absorption spectroscopy, analytical transmission electron microscopy (ATEM), inductively coupled plasma atomic emission spectroscopy (ICP-AES), and extended X-ray absorption fine structure (EXAFS) measurements. Moreover, the time evolution of size and shape distribution has been investigated by statistical analysis of the relevant TEM data. EXAFS measurements at the Ag K-edge have unambiguously disclosed the presence of Ag species in the final product, identifying their chemical state as well as the most probable lattice environment around them with a reasonably high level of confidence. The extensive sample knowl...
82 citations
TL;DR: In this paper, the authors used synchrotron extended X-ray absorption fine structure (EXAFS) to quantify local thermal and static disorder and to characterize strontium coordination in a variety of oxygen-ligated bonding environments.
82 citations