Structural study and electrical properties of Zr-doped Nd2Sn2O7 pyrochlore compounds

Autor:	Keka R. Chakraborty, S. K. Paranjpe, Y.D. Kolekar, A.K. Das, S. B. Kulkarni, P. B. Joshi
Rok vydání:	2004
Předmět:	Diffraction Materials science Neutron diffraction Doping Pyrochlore Analytical chemistry General Physics and Astronomy Conductivity engineering.material visual_art engineering visual_art.visual_art_medium Grain boundary Ceramic Electron backscatter diffraction
Zdroj:	Pramana. 63:189-197
ISSN:	0973-7111 0304-4289
DOI:	10.1007/bf02704972
Popis:	Nd2Sn2O7 pyrochlores with the substitution of Zr4+ were prepared by conventional ceramic double sintering technique. The single-phase formation was confirmed by X-ray diffraction and neutron diffraction techniques. Relative intensity calculations for X-ray diffraction analysis were performed for oxygen positional parametersx = 0.331 and 0.375, while Rietveld refinements were employed for neutron diffraction data. The neutron diffraction study revealed that there are only two anion sites with 48f and 8b positions. This indicates that the 8a site, i.e. O(3) sublattice, is completely vacant and the structure is a perfect cubic pyrochlore with space group Fd3m (Oh7). From the conductivity measurements, it is observed that the electronic conductivity dominates from room temperature up to about 525 K and forT > 525 K, the oxygen ion conduction dominates the charge transport in these compositions. Complex impedance spectroscopy indicates the existence of grain and grain boundary as two separate elements.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::574ccf782f97e07ba852e7a873e4d78a https://doi.org/10.1007/bf02704972 Zobrazit plný text záznamu Full text from SpringerLink