dc.contributorUniversidade Estadual Paulista (UNESP)
dc.creatorAlmeida, Luciano Henrique de
dc.creatorPires, Kelly Cristina Cezaretto
dc.creatorGrandini, Carlos Roberto
dc.creatorFlorêncio, Odila
dc.date2014-05-20T13:26:13Z
dc.date2014-05-20T13:26:13Z
dc.date2005-09-01
dc.date.accessioned2017-04-05T20:04:54Z
dc.date.available2017-04-05T20:04:54Z
dc.identifierMaterials Research. ABM, ABC, ABPol, v. 8, n. 3, p. 239-243, 2005.
dc.identifier1516-1439
dc.identifierhttp://hdl.handle.net/11449/8418
dc.identifier10.1590/S1516-14392005000300003
dc.identifierS1516-14392005000300003
dc.identifierS1516-14392005000300003.pdf
dc.identifier0000-0002-3336-309X
dc.identifierhttp://dx.doi.org/10.1590/S1516-14392005000300003
dc.identifier.urihttp://repositorioslatinoamericanos.uchile.cl/handle/2250/856788
dc.descriptionImpurity interstitial atoms present in metals with BCC structure can diffuse in the metallic matrix by jumps to energetically equivalent crystallographic sites. Anelastic spectroscopy (internal friction) is based on the measurement of mechanical loss or internal friction as a function of temperature. Due to its selective and nondestructive nature, anelastic spectroscopy is well suited for the study of diffusion of interstitial elements in metals. Internal friction measurements were made using the torsion pendulum technique with oscillation frequency of a few Hz, temperature interval from 300 to 700 K, heating rate of about 1 K/min, and vacuum better than 10-5 mbar. The polycrystalline Nb and Ta samples used were supplied by Aldrich Inc. The results obtained showed thermally activated relaxation structures due to stress-induced ordering of oxygen atoms around the Nb (or Ta) atoms of the metallic matrix. The results were interpreted by three methods and led to activation enthalpy values for the diffusion of oxygen in Nb and Ta of 1.15 eV and 1.10 eV, respectively.
dc.languageeng
dc.publisherABM, ABC, ABPol
dc.relationMaterials Research
dc.rightsinfo:eu-repo/semantics/openAccess
dc.subjectoxygen diffusion
dc.subjectinternal friction
dc.subjectinterstitials
dc.subjectNb
dc.subjectTa
dc.titleMeasurement of oxygen atom diffusion in Nb and Ta by anelastic spectroscopy
dc.typeOtro


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