dc.contributor.author | Vullum, Fride | |
dc.contributor.author | Nitsche, Fabian | |
dc.contributor.author | Selbach, Sverre Magnus | |
dc.contributor.author | Grande, Tor | |
dc.date.accessioned | 2014-12-01T13:05:37Z | |
dc.date.accessioned | 2016-05-18T11:12:39Z | |
dc.date.available | 2014-12-01T13:05:37Z | |
dc.date.available | 2016-05-18T11:12:39Z | |
dc.date.issued | 2008 | |
dc.identifier.citation | Journal of Solid State Chemistry 2008, 181(10):2580-2585 | nb_NO |
dc.identifier.issn | 0022-4596 | |
dc.identifier.uri | http://hdl.handle.net/11250/2389570 | |
dc.description.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. | nb_NO |
dc.language.iso | eng | nb_NO |
dc.publisher | Elsevier | nb_NO |
dc.title | Solid solubility and phase transitions in the system LaNb1-xTaxO4 | nb_NO |
dc.type | Journal article | nb_NO |
dc.type | Peer reviewed | nb_NO |
dc.date.updated | 2014-12-01T13:05:37Z | |
dc.source.volume | 181 | nb_NO |
dc.source.journal | Journal of Solid State Chemistry | nb_NO |
dc.source.issue | 10 | nb_NO |
dc.identifier.doi | 10.1016/j.jssc.2008.06.032 | |
dc.identifier.cristin | 361699 | |
dc.description.localcode | (c) 2008 Elsevier Inc. All rights reserved. This is the authors' accepted and refereed maniscript to the article. | nb_NO |