• norsk
    • English
  • English 
    • norsk
    • English
  • Login
View Item 
  •   Home
  • Øvrige samlinger
  • Publikasjoner fra CRIStin - NTNU
  • View Item
  •   Home
  • Øvrige samlinger
  • Publikasjoner fra CRIStin - NTNU
  • View Item
JavaScript is disabled for your browser. Some features of this site may not work without it.

Solid solubility and phase transitions in the system LaNb1-xTaxO4

Vullum, Fride; Nitsche, Fabian; Selbach, Sverre Magnus; Grande, Tor
Journal article, Peer reviewed
Thumbnail
View/Open
LaNb1-xTaxO4-210108(revised).doc (615Kb)
URI
http://hdl.handle.net/11250/2389570
Date
2008
Metadata
Show full item record
Collections
  • Institutt for materialteknologi [2407]
  • Publikasjoner fra CRIStin - NTNU [34969]
Original version
Journal of Solid State Chemistry 2008, 181(10):2580-2585   10.1016/j.jssc.2008.06.032
Abstract
The solid solubility between LaNbO4 and LaTaO4 was investigated by X-ray diffraction, and a two-phase region was observed in the composition region LaNb1−xTaxO4 where 0.4⩽x⩽0.8. Single-phase LaNb1−xTaxO4 (0⩽x⩽0.4) with the monoclinic Fergusonite structure at ambient temperature, was observed to transform to a tetragonal Scheelite structure by in-situ high-temperature X-ray diffraction, and the phase transition temperature was shown to increase with increasing Ta-content. This ferroelastic to paraelastic second-order phase transition was described by Landau theory using spontaneous strain as an order parameter. The thermal expansion of LaNb1−xTaxO4 (0⩽x0.4) was shown to be significantly higher below the phase transition than above. Single-phase LaNb1−xTaxO4 (0.8⩽x⩽1) with another monoclinic crystal structure at ambient temperature was shown to transform to an orthorhombic crystal structure by X-ray diffraction and differential scanning calorimetry. The phase transition temperature was observed to decrease with decreasing Ta-content. Finally, orthorhombic LaTaO4 could also be transformed to monoclinic LaTaO4 at ambient temperature by applying a uniaxial pressure of 150–170 MPa, reflecting the lower molar volume of monoclinic LaTaO4.
Publisher
Elsevier
Journal
Journal of Solid State Chemistry

Contact Us | Send Feedback

Privacy policy
DSpace software copyright © 2002-2019  DuraSpace

Service from  Unit
 

 

Browse

ArchiveCommunities & CollectionsBy Issue DateAuthorsTitlesSubjectsDocument TypesJournalsThis CollectionBy Issue DateAuthorsTitlesSubjectsDocument TypesJournals

My Account

Login

Statistics

View Usage Statistics

Contact Us | Send Feedback

Privacy policy
DSpace software copyright © 2002-2019  DuraSpace

Service from  Unit