Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Phase equilibrian and thermodynamics of rare earth-iron systems
KTH, Superseded Departments, Materials Science and Engineering.
2000 (English)Doctoral thesis, comprehensive summary (Other scientific)
Abstract [en]

The present thesis was initiated by a quest for knowledgeabout the Fe-Tb-Dy system and is focused on the basicthermodynamics of the rare-earth systems with primarily iron.The final aim is to create a thermodynamic database for rareearth-iron systems, a database from which all phase diagramsand thermodynamic properties of interest may be calculated. Theemphasis is on the iron-rare earth systems but occasionallyother systems are considered, e.g. when a more systematic studyis performed in order to extrapolate necessary properties.

In the thesis calculations, empirical predictions, e.g.based on the atomic number, and assessments are combined withexperimental investigations. During this work many questions ofmore fundamental nature appeared and some of them are tackledin the thesis. One may mention particularly:

- In the Fe-Dy and Fe-Tb systems, the lack of thermodynamicdata led to several questions. For example, is it possible toobtain reliable values for the enthalpies of formation for theintermetallic phases by considering trends in the periodictable? Thus a systematic study, to predict the enthalpies offormation of the Laves phases, including the rare earth- iron,cobalt and nickel systems was performed, and the enthalpies forthe intermetallic phases in the Fe-Dy and Fe-Er systems weremeasured.

- The solubility of Fe in Dy and Dy in Fe are determined bythe so-called lattice stabilities. These quantities arepredicted in the thesis by assessing intra rare earthsystems.

- The transformation between the different close-packedstructures, e.g. dhcp and hcp, is controversial. Is there atwo-phase field between dhcp and hcp in the phase diagram orcan the two phases gradually transform into each? According tothe latest review article in the field such a gradualtransformation is indeed possible. However, when criticallyexamining the crystallographic relations and studying the earlyarticles on the Nd-Sc system the present author concluded thatthe transformation must always be first order, i.e. there mustbe a two-phase field.

- The Fe2Dy phases is a ferrimagnetic compound. The effectof the magnetism on the thermodynamic properties isconsidered.

Key Words:Rare earth metals, Terfenol-D, Laves phase,Enthalpy, experiment, Magnetostrictive material, intra rareearth systems, Fe-Tb, Dy-Fe, Dy-Fe-Tb, Er-Ho, Dy-Ho, Ho-Tb,Er-Tb, Dy-Er, Gd-Sc, Nd-Sc, Sc-Y, Heat capacity, Thermodynamic,Phase Equilibria

Place, publisher, year, edition, pages
Stockholm: Materialvetenskap , 2000. , 28 p.
Identifiers
URN: urn:nbn:se:kth:diva-2912ISBN: 91-7170-514-7 (print)OAI: oai:DiVA.org:kth-2912DiVA: diva2:8648
Public defence
2000-02-11
Note
NR 20140805Available from: 2000-03-24 Created: 2000-03-24Bibliographically approved

Open Access in DiVA

fulltext(172 kB)1919 downloads
File information
File name FULLTEXT01.pdfFile size 172 kBChecksum MD5
ac30d312a51f7c09b93528bf05a8b62720077996f9fc1294e315c2f4b6f021d9c9498e63
Type fulltextMimetype application/pdf

By organisation
Materials Science and Engineering

Search outside of DiVA

GoogleGoogle Scholar
Total: 1919 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

isbn
urn-nbn

Altmetric score

isbn
urn-nbn
Total: 836 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf