Structural and Photoacoustic Study of Cr11Ge19 Prepared by Mechanical Alloying
Autor(a) principal: | |
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Data de Publicação: | 2017 |
Outros Autores: | , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Materials research (São Carlos. Online) |
Texto Completo: | http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392017000401072 |
Resumo: | A nanostructured Cr11Ge19 phase was produced by mechanical alloying for 15 h. Decomposition occurred for larger milling times, yielding Cr, Ge, Cr2O3 and GeO2. According to the Cr-Ge phase diagram, the Cr11Ge19 phase is stable up to ≈ 928 oC, but, when submitted to milling, a structural instability causes its decomposition. We studied this structural instability using the coordination numbers and interatomic distances of bulk Cr11Ge19 to simulate the structure factors SCrCr(K), SCrGe(K), and SGeGe(K). The radial distribution functions RDFCrCr(R), RDFCrGe(R) and RDFGeGe(R) were obtained by Fourier transforming the Sij(K) factors, and an important chemical disorder up to ≈7 Å was observed in the RDFCrGe(R) and RDFGeGe(R) functions. This chemical disorder was quantified using Cowley-Warren α ij CW parameter. The thermoelectric properties of the Cr11Ge19 phase were also studied. |
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Materials research (São Carlos. Online) |
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Structural and Photoacoustic Study of Cr11Ge19 Prepared by Mechanical AlloyingMechanical alloyingX-ray diffractionRietveld methodPhotoacoustic absorption spectroscopyThermal diffusivityA nanostructured Cr11Ge19 phase was produced by mechanical alloying for 15 h. Decomposition occurred for larger milling times, yielding Cr, Ge, Cr2O3 and GeO2. According to the Cr-Ge phase diagram, the Cr11Ge19 phase is stable up to ≈ 928 oC, but, when submitted to milling, a structural instability causes its decomposition. We studied this structural instability using the coordination numbers and interatomic distances of bulk Cr11Ge19 to simulate the structure factors SCrCr(K), SCrGe(K), and SGeGe(K). The radial distribution functions RDFCrCr(R), RDFCrGe(R) and RDFGeGe(R) were obtained by Fourier transforming the Sij(K) factors, and an important chemical disorder up to ≈7 Å was observed in the RDFCrGe(R) and RDFGeGe(R) functions. This chemical disorder was quantified using Cowley-Warren α ij CW parameter. The thermoelectric properties of the Cr11Ge19 phase were also studied.ABM, ABC, ABPol2017-08-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersiontext/htmlhttp://old.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392017000401072Materials Research v.20 n.4 2017reponame:Materials research (São Carlos. Online)instname:Universidade Federal de São Carlos (UFSCAR)instacron:ABM ABC ABPOL10.1590/1980-5373-mr-2016-0788info:eu-repo/semantics/openAccessFerreira,Ailton da SilvaPrates,Patricia BodanesePoffo,Claudio MichelLima,João Cardoso deBiasi,Ronaldo Sergio deeng2017-09-05T00:00:00Zoai:scielo:S1516-14392017000401072Revistahttp://www.scielo.br/mrPUBhttps://old.scielo.br/oai/scielo-oai.phpdedz@power.ufscar.br1980-53731516-1439opendoar:2017-09-05T00:00Materials research (São Carlos. Online) - Universidade Federal de São Carlos (UFSCAR)false |
dc.title.none.fl_str_mv |
Structural and Photoacoustic Study of Cr11Ge19 Prepared by Mechanical Alloying |
title |
Structural and Photoacoustic Study of Cr11Ge19 Prepared by Mechanical Alloying |
spellingShingle |
Structural and Photoacoustic Study of Cr11Ge19 Prepared by Mechanical Alloying Ferreira,Ailton da Silva Mechanical alloying X-ray diffraction Rietveld method Photoacoustic absorption spectroscopy Thermal diffusivity |
title_short |
Structural and Photoacoustic Study of Cr11Ge19 Prepared by Mechanical Alloying |
title_full |
Structural and Photoacoustic Study of Cr11Ge19 Prepared by Mechanical Alloying |
title_fullStr |
Structural and Photoacoustic Study of Cr11Ge19 Prepared by Mechanical Alloying |
title_full_unstemmed |
Structural and Photoacoustic Study of Cr11Ge19 Prepared by Mechanical Alloying |
title_sort |
Structural and Photoacoustic Study of Cr11Ge19 Prepared by Mechanical Alloying |
author |
Ferreira,Ailton da Silva |
author_facet |
Ferreira,Ailton da Silva Prates,Patricia Bodanese Poffo,Claudio Michel Lima,João Cardoso de Biasi,Ronaldo Sergio de |
author_role |
author |
author2 |
Prates,Patricia Bodanese Poffo,Claudio Michel Lima,João Cardoso de Biasi,Ronaldo Sergio de |
author2_role |
author author author author |
dc.contributor.author.fl_str_mv |
Ferreira,Ailton da Silva Prates,Patricia Bodanese Poffo,Claudio Michel Lima,João Cardoso de Biasi,Ronaldo Sergio de |
dc.subject.por.fl_str_mv |
Mechanical alloying X-ray diffraction Rietveld method Photoacoustic absorption spectroscopy Thermal diffusivity |
topic |
Mechanical alloying X-ray diffraction Rietveld method Photoacoustic absorption spectroscopy Thermal diffusivity |
description |
A nanostructured Cr11Ge19 phase was produced by mechanical alloying for 15 h. Decomposition occurred for larger milling times, yielding Cr, Ge, Cr2O3 and GeO2. According to the Cr-Ge phase diagram, the Cr11Ge19 phase is stable up to ≈ 928 oC, but, when submitted to milling, a structural instability causes its decomposition. We studied this structural instability using the coordination numbers and interatomic distances of bulk Cr11Ge19 to simulate the structure factors SCrCr(K), SCrGe(K), and SGeGe(K). The radial distribution functions RDFCrCr(R), RDFCrGe(R) and RDFGeGe(R) were obtained by Fourier transforming the Sij(K) factors, and an important chemical disorder up to ≈7 Å was observed in the RDFCrGe(R) and RDFGeGe(R) functions. This chemical disorder was quantified using Cowley-Warren α ij CW parameter. The thermoelectric properties of the Cr11Ge19 phase were also studied. |
publishDate |
2017 |
dc.date.none.fl_str_mv |
2017-08-01 |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392017000401072 |
url |
http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392017000401072 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
10.1590/1980-5373-mr-2016-0788 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
text/html |
dc.publisher.none.fl_str_mv |
ABM, ABC, ABPol |
publisher.none.fl_str_mv |
ABM, ABC, ABPol |
dc.source.none.fl_str_mv |
Materials Research v.20 n.4 2017 reponame:Materials research (São Carlos. Online) instname:Universidade Federal de São Carlos (UFSCAR) instacron:ABM ABC ABPOL |
instname_str |
Universidade Federal de São Carlos (UFSCAR) |
instacron_str |
ABM ABC ABPOL |
institution |
ABM ABC ABPOL |
reponame_str |
Materials research (São Carlos. Online) |
collection |
Materials research (São Carlos. Online) |
repository.name.fl_str_mv |
Materials research (São Carlos. Online) - Universidade Federal de São Carlos (UFSCAR) |
repository.mail.fl_str_mv |
dedz@power.ufscar.br |
_version_ |
1754212671060705280 |