Diffusion phenomena of the oxygen and nitrogen in niobium by mechanical spectroscopy
Defect and Diffusion Forum, v. 297-301, p. 1346-1353.
Silva, P. S.
Grandini, Carlos Roberto
The short-range diffusion phenomenon (Snoek Effect) was investigated by mechanical spectroscopy measurements between 300 K and 650 K, in a polycrystalline niobium sample, containing oxygen and nitrogen, using a torsion pendulum. Experimental spectra of anelastic relaxation were obtained under three conditions: as-received sample; annealed sample and subsequently annealed in an oxygen atmosphere for three hours at 1170 K in partial pressure of 5°10 -5mbar. The experimental spectra obtained were decomposed in elementary Debye peaks and the anelastic relaxation processes were identified. With anelastic relaxation parameters and the lattice parameters, the interstitial diffusion coefficients of the oxygen and nitrogen in niobium were calculated for each kind of preferential occupation (octahedral and tetrahedral). The results were compared with the literature data, and confirmed that the best adjustment is for the preferential occupation octahedral model for low concentrations of interstitial solutes, but at higher concentration of oxygen were observed deviations of experimental data for the interstitial diffusion coefficients of oxygen in niobium when compared with the literature data, this could be related to the possible occurrence of a double occupation of interstitial sites in the niobium lattice by oxygen interstitials. © (2010) Trans Tech Publications.
Showing items related by title, author, creator and subject.
Larez, Hanzel; Leiva A., Hugo Antonio
Modeling transition diffusive - non diffusive transport in a turbid media and application to time-resolved reflectance Di Rocco, Hector Omar; Carbone, Nicolás Abel; Iriarte, Daniela Ines; Pomarico, Juan Antonio; Ranea Sandoval, Hector Francisco (Elsevier, 2013-02)In this work a generalized solution for the photon density is proposed and applied to two types of experiments in turbid media carried out in the last years. Both involve small typical distances, where it is known that the ...
Fluorescence correlation spectroscopy experiments to quantify free diffusion coefficients in reaction-diffusion systems: The case of Ca 2 + and its dyes Sigaut, Lorena; Villarruel, Cecilia Liliana; Ponce, Maria Laura Ponce; Ponce Dawson, Silvina Martha (American Physical Society, 2017-06)Many cell signaling pathways involve the diffusion of messengers that bind and unbind to and from intracellular components. Quantifying their net transport rate under different conditions then requires having separate ...