English   español  
Please use this identifier to cite or link to this item: http://hdl.handle.net/10261/55684
Title: Structural properties of Pb2MnW1−xRexO6 double perovskites
Authors: Lafuerza, Sara; Blasco, Javier; García, Joaquín; Subías, G.; Cuartero, Vera; Merino, R. I.
Issue Date: 2012
Publisher: Institute of Physics Publishing
Citation: Journal of Physics: Condensed Matter 24(7): 075403 (2012)
Abstract: Pb2MnW1−xRexO6 samples have been synthesized and their structure determined by powder x-ray diffraction. These samples undergo a first order structural phase transition between 413 and 445 K depending on the composition. Above this temperature, the samples are cubic. Below the transition temperature, solid solutions are found for x ≤ 0.2 and x ≥ 0.5. The W-rich samples adopt an orthorhombic cell whereas the Re-rich compounds are monoclinic. In the intermediate region, 0.2 < x < 0.5, both phases coexist. X-ray absorption spectra did not reveal significant changes in the local structure for Pb, Mn or Re atoms across the structural phase transition. All the atoms exhibit distorted environments in the whole series. In the case of Pb and W(Re) atoms, the local distortion remains in the high temperature phase. Samples with x ≤ 0.2 also show a sharp discontinuity in the dielectric permittivity at the phase transition temperature indicating the presence of a concomitant electrical ordering in the bulk grains. Such an anomaly in the dielectric constant is not observed for the x ≥ 0.5 samples, compatible with the lack of dipole ordering for this composition range. The different electrical behaviours also explain the differences in the entropy content for the two types of transition.
Description: 10 páginas, 12 figuras.-- El pdf del artículo es la versión post-print.
Publisher version (URL): http://dx.doi.org/10.1088/0953-8984/24/7/075403
URI: http://hdl.handle.net/10261/55684
DOI: 10.1088/0953-8984/24/7/075403
ISSN: 0953-8984
E-ISSN: 1361-648X
Appears in Collections:(ICMA) Artículos
Files in This Item:
File Description SizeFormat 
Structural properties.pdf492,45 kBAdobe PDFThumbnail
Show full item record

WARNING: Items in Digital.CSIC are protected by copyright, with all rights reserved, unless otherwise indicated.