• English
    • Norsk
  • English 
    • English
    • Norsk
  • Administration
View Item 
  •   Home
  • Øvrige samlinger
  • Høstingsarkiver
  • CRIStin høstingsarkiv
  • View Item
  •   Home
  • Øvrige samlinger
  • Høstingsarkiver
  • CRIStin høstingsarkiv
  • View Item
JavaScript is disabled for your browser. Some features of this site may not work without it.

Relating defect chemistry and electronic transport in the double perovskite Ba1-xGd0.8La0.2+xCo2O6-d (BGLC)

Vøllestad, Einar; Schrade, Matthias; Segalini, Julie; Strandbakke, Ragnar; Norby, Truls Eivind
Journal article; SubmittedVersion
View/Open
defect+chemistry+BGLC+JMCA+revised+20170706.pdf (1.601Mb)
Year
2017
Permanent link
http://urn.nb.no/URN:NBN:no-66320

CRIStin
1502783

Metadata
Show metadata
Appears in the following Collection
  • Kjemisk institutt [843]
  • CRIStin høstingsarkiv [15984]
Original version
Journal of Materials Chemistry A. 2017, 5 (30), 15743-15751, DOI: http://dx.doi.org/10.1039/c7ta02659e
Abstract
Rare earth double perovskites comprise a class of functional oxides with interesting physiochemical properties both for low- and high-temperature applications. However, little can be found relating electrical properties with equilibrium thermodynamics of non-stoichiometry and defects. In the present work, a comprehensive and generally applicable defect chemical model is developed to form the link between the defect chemistry and electronic structure of partially substituted BGLC (Ba1−xGd0.8La0.2+xCo2O6−δ, 0 ≤ x ≤ 0.5). The equilibrium oxygen content of 4 different compositions is determined as a function of pO2 and temperature by thermogravimetric analysis, and combined with defect chemical modelling to obtain defect concentrations and thermodynamic parameters. Oxidation enthalpies determined by TG-DSC become increasingly exothermic (−50 to −120 kJ mol−1) with increased temperature and oxygen non-stoichiometry for all compositions, in excellent agreement with the thermodynamic parameters obtained from the defect chemical model. All compositions display high electrical conductivities (500 to 1000 S cm−1) with shallow pO2-dependencies and small and positive Seebeck coefficients (3 to 15 μV K−1), indicating high degree of degeneracy of the electronic charge carriers. The complex electrical properties of BGLC at elevated temperatures is rationalized by a two-band conduction model where highly mobile p-type charge carriers are transported within the valence band, whereas less mobile “n-type” charge carriers are located in narrow Co 3d band.
 
Responsible for this website 
University of Oslo Library


Contact Us 
duo-hjelp@ub.uio.no


Privacy policy
 

 

For students / employeesSubmit master thesisAccess to restricted material

Browse

All of DUOCommunities & CollectionsBy Issue DateAuthorsTitlesThis CollectionBy Issue DateAuthorsTitles

For library staff

Login
RSS Feeds
 
Responsible for this website 
University of Oslo Library


Contact Us 
duo-hjelp@ub.uio.no


Privacy policy