X-ray structure refinement of solid solution Ba2.15-xNa0.7+xNb5-xWxO15 and the investigation of the orthorhombic-tetragonal phase transition by Raman spectroscopy
2011 (English)In: Journal of Molecular Structure, ISSN 0022-2860, E-ISSN 1872-8014, Vol. 988, no 1-3, 136-143 p.Article in journal (Refereed) Published
Crystal structures of Ba2.15-xNa0.7+xNb5-xWxO15 (BaNaNbW) materials were investigated by X-ray diffraction and refined using the Rietveld method. It is shown that all the samples crystallize in the tungsten tetragonal bronze (TTB) like structure and form a solid solution in the range (0 ≤ x ≤ 1). To study the temperature induced phase transition in these compounds, Raman spectra were collected in situ at room pressure and elevated temperatures, up to 330°. The Raman results show strong evidence that the materials under study go through a phase transition around Te = 270 °C. The value of the transition temperature depends on the chemical composition and increases with increasing tungsten content in the materials at a linear rate. The observation of this phase transition by Raman technique is in agreement with dielectric spectroscopy anomaly.
Place, publisher, year, edition, pages
2011. Vol. 988, no 1-3, 136-143 p.
Phase transition, Raman spectroscopy, TTB structure, XRD
Earth and Related Environmental Sciences
IdentifiersURN: urn:nbn:se:uu:diva-141095DOI: 10.1016/j.molstruc.2010.12.043ISI: 000288525400018OAI: oai:DiVA.org:uu-141095DiVA: diva2:384970