Ändra sökning
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Structural stability of intermetallic phases in the Zr-Sn system
KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.ORCID-id: 0000-0002-9920-5393
KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Termodynamisk modellering.
Visa övriga samt affilieringar
2006 (Engelska)Ingår i: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 55, nr 5, s. 485-488Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

A thermodynamic description of the intermetallic compounds in the Zr-Sn binary system has been obtained using total energy calculations by means of the Vienna ab initio simulation package. Our calculations show that hexagonal compounds Zr5Sn4 and Zr5Sn3 are the most stable phases in the Zr-Sn binary system. Their high stability is found to be due to hybridization of the Sn 5p with Zr 4d electronic states. Based on the calculated energies, the conclusion is made that Zr substitution on the Sri sites takes place in the Zr4Sn phase, which accounts for the unusual stoichiometry of this Cr3Si structure type compound.

Ort, förlag, år, upplaga, sidor
2006. Vol. 55, nr 5, s. 485-488
Nyckelord [en]
zirconium-tin alloys; intermetallic compounds; first-principle electron theory
Nationell ämneskategori
Metallurgi och metalliska material Den kondenserade materiens fysik
Identifikatorer
URN: urn:nbn:se:kth:diva-5594DOI: 10.1016/j.scriptamat.2006.04.047ISI: 000239132200017Scopus ID: 2-s2.0-33745209870OAI: oai:DiVA.org:kth-5594DiVA, id: diva2:10011
Anmärkning

QC 20150728

Tillgänglig från: 2006-04-11 Skapad: 2006-04-11 Senast uppdaterad: 2017-12-14Bibliografiskt granskad
Ingår i avhandling
1. Thermodynamic Database for Zirconium Alloys
Öppna denna publikation i ny flik eller fönster >>Thermodynamic Database for Zirconium Alloys
2006 (Engelska)Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
Abstract [en]

For many decades zirconium alloys have been commonly used in the nuclear power industry as fuel cladding material. Besides their good corrosion resistance and acceptable mechanical properties the main reason for using these alloys is the low neutron absorption.

Zirconium alloys are exposed to a very severe environment during the nuclear fission process and there is a demand for better design of this material. To meet this requirement a thermodynamic database is useful to support material designers. In this thesis some aspects of the development of a thermodynamic database for zirconium alloys are presented. A thermodynamic database represents an important facility in applying thermodynamic equilibrium calculations for a given material providing: 1) relevant information about the thermodynamic properties of the alloys e.g. amount and composition of phases, oxygen activity, heat capacity etc, and 2) significant information for the manufacturing process e.g. heat treatment temperature.

The basic information in the database is first the unary data, i.e. pure elements; those are taken from the compilation of the Scientific Group Thermodata Europe (SGTE) and then the binary and ternary systems. All phases present in those binary and ternary systems are described by means of the Gibbs energy as a function of composition and temperature. Many of those binary systems have been taken from published or unpublished works and others have been assessed in the present work. The elements included in the databse are: C, Fe, Cr, Nb, Ni, Mo, O, Si, Sn, and Zr + H, and the assessment performed under this thesis are: Cr-Sn, Mo-Zr, Sn-Zr, Fe-Nb-Zr and Nb-O-Zr. All the calculations have been made using Thermo-Calc software and the representation of the Gibbs energy obtained by applying Calphad technique with some use of ab initio calculations.

Ort, förlag, år, upplaga, sidor
Stockholm: KTH, 2006. s. xii, 50
Nyckelord
Zirconium alloys, thermodynamic equilibrium, thermodynamic properties, binary system, ternary system, Gibbs energy, Thermo-Calc, Calphad, binary system, ternary system
Nationell ämneskategori
Annan materialteknik
Identifikatorer
urn:nbn:se:kth:diva-3918 (URN)91-7178-308-3 (ISBN)
Disputation
2006-04-24, Sal F3, Lindstedtsvägen 26, Stockholm, 10:00
Opponent
Handledare
Anmärkning
QC 20100902Tillgänglig från: 2006-04-11 Skapad: 2006-04-11 Senast uppdaterad: 2010-09-02Bibliografiskt granskad
2. Point defect interactions and structural stability of compounds
Öppna denna publikation i ny flik eller fönster >>Point defect interactions and structural stability of compounds
2007 (Engelska)Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
Abstract [en]

Theoretical studies of point defect interactions and structural stability of compounds have been performed using density functional theory. The defect-related properties, such as activation energy of diffusion, electronic and magnetic structure of selected materials have been studied.

The major part of the present work is devoted to a very important material for semiconductor industry, GaAs. The formation energies of intrinsic point defects and the solution energies of 3d transitions in GaAs have been calculated from first principles. Based on the calculated energies, we analysed the site preference of defects in the crystal. The tendency of defects to form clusters has been investigated for the intrinsic defects as well as for impurities in GaAs. The magnetic moment of 3d impurities has been calculated as a function of the chemical environment. The possibility of increasing the Curie temperature in (Ga,Mn)As by co-doping it with Cr impurities has been examined on the basis of calculated total energy difference between the disordered local moment and the ferromagnetically ordered spin configurations. We found that, in order to reach the highest critical temperature, GaAs should be separately doped with either Cr or Mn impurities. Also, we have shown that diffusion barrier of interstitial Mn depends on the charge state of this impurity in (Ga, Mn)As. The formation of defect complexes between interstitial and substitutional Mn atoms, and their influence on the value of diffusion barrier for interstitial Mn, has been studied.

The pair interactions energies between interstitial oxygen atoms in hcp Zr, Hf and Ti have been calculated using first principles. Based on the calculated energies, the oxygen ordering structures in IVB transition metal solid solutions have been explained. A prediction of nitrogen ordering in Hf-N solid solution has been made.

The thermodynamic description of intermetallic compounds in the Zr-Sn binary system has been obtained. The conclusion has been made that Zr substitution on the Sn sites takes place in the Zr4Sn phase, which accounts for the unusual stoichiometry of this Cr3Si structure type compound.

The influence of pressure on the phase stability in the Fe-Si system has been investigated. We have found instability of the hcp Fe0.9Si0.1 random alloy with respect to the decomposition onto the Si-poor hcp Fe alloy and the B2 FeSi under high pressure. The tendency of this decomposition becomes stronger with increasing the applied pressure.

Ort, förlag, år, upplaga, sidor
Stockholm: KTH, 2007
Nyckelord
first principles, ab initio, density functional theory, point defects interactions, diluted magnetic semiconductors, structural stability, zirconium alloys
Nationell ämneskategori
Annan materialteknik
Identifikatorer
urn:nbn:se:kth:diva-4605 (URN)978-91-7178-842-9 (ISBN)
Disputation
2008-01-28, Sal F3, KTH, Lindstedtsvägen 26, Stockholm, 10:00
Opponent
Handledare
Anmärkning
QC 20100624Tillgänglig från: 2008-01-15 Skapad: 2008-01-15 Senast uppdaterad: 2012-03-19Bibliografiskt granskad

Open Access i DiVA

Fulltext saknas i DiVA

Övriga länkar

Förlagets fulltextScopus

Personposter BETA

Korzhavyi, Pavel A.

Sök vidare i DiVA

Av författaren/redaktören
Baykov, VitalyJerlerud Perez, RosaKorzhavyi, Pavel A.Sundman, BoJohansson, Börje
Av organisationen
MaterialvetenskapTermodynamisk modelleringTillämpad materialfysik
I samma tidskrift
Scripta Materialia
Metallurgi och metalliska materialDen kondenserade materiens fysik

Sök vidare utanför DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetricpoäng

doi
urn-nbn
Totalt: 350 träffar
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf