Cart (Loading....) | Create Account
Close category search window
 

Evaluation of Sr2MMoO6 (M = Mg, Mn) as anode materials in solid-oxide fuel cells: A neutron diffraction study

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

Formats Non-Member Member
$31 $31
Learn how you can qualify for the best price for this item!
Become an IEEE Member or Subscribe to
IEEE Xplore for exclusive pricing!
close button

puzzle piece

IEEE membership options for an individual and IEEE Xplore subscriptions for an organization offer the most affordable access to essential journal articles, conference papers, standards, eBooks, and eLearning courses.

Learn more about:

IEEE membership

IEEE Xplore subscriptions

4 Author(s)
Troncoso, L. ; Departamento de Física, Facultad de Ciencias, Universidad de Santiago de Chile, Av. Lib. Bernardo O'Higgins 3363, Santiago, Chile ; Martinez-Lope, M. J. ; Alonso, J. A. ; Fernandez-Diaz, M. T.

Your organization might have access to this article on the publisher's site. To check, click on this link:http://dx.doi.org/+10.1063/1.4774764 

Sr2MMoO6 (M = Mg, Mn) double perovskites have recently been proposed as anode materials in solid-oxide fuel cells (SOFC). The evolution of their crystal structures has been followed by “in situ” temperature-dependent neutron powder diffraction from 25 °C room temperature (RT) to 930 °C by heating in ultrahigh vacuum (PO2 ≈ 10-6 Torr) in order to simulate the reducing atmosphere corresponding to the working conditions of an anode in a SOFC. At RT, the samples are described as tetragonal (I4/m space group) and monoclinic (P21/n) for M = Mg, Mn, respectively. Sr2MgMoO6 undergoes a structural phase transition from tetragonal to cubic (Fm-3m) below 300 °C; Sr2MnMoO6 experiences two consecutive phase transitions to tetragonal (I4/m) and finally cubic (Fm-3m) at 600 °C and above. In the cubic phases, the absence of octahedral tilting accounts for a good overlap between the oxygen and transition-metal orbitals, resulting in a good electronic conductivity; a high mobility of the oxygen atoms is derived from the elevated displacement parameters, for instance 3.0 Å2 and 4.6 Å2 at 930 °C for M = Mg, Mn, respectively. Both factors contribute to the excellent performance described for these mixed ionic and electronic conductor oxides as anodes in single fuel cells. From dilatometric measurements, the thermal expansion coefficients (TEC) in the cubic region are 12.7 × 10-6 K-1 and 13.0 × 10-6 K-1 for M = Mg and Mn, respectively. These figures are comparable to those obtained from the mentioned structural analysis; moreover, the TECs for the cubic phases perfectly match those of the us- al electrolytes in a SOFC.

Published in:

Journal of Applied Physics  (Volume:113 ,  Issue: 2 )

Date of Publication:

Jan 2013

Need Help?


IEEE Advancing Technology for Humanity About IEEE Xplore | Contact | Help | Terms of Use | Nondiscrimination Policy | Site Map | Privacy & Opting Out of Cookies

A not-for-profit organization, IEEE is the world's largest professional association for the advancement of technology.
© Copyright 2014 IEEE - All rights reserved. Use of this web site signifies your agreement to the terms and conditions.