Stability and transport properties of La2Mo2O9

authors	Marrero-Lopez, D; Ruiz-Morales, JC; Perez-Coll, D; Nunez, P; Abrantes, JCC; Frade, JR
nationality	International
journal	JOURNAL OF SOLID STATE ELECTROCHEMISTRY
author keywords	coulometric titration; freeze-dried precursor; ion blocking; lanthanum molybdenum oxide; phase transition
keywords	OXIDE-ION CONDUCTORS
abstract	La2Mo2O9 samples were prepared from freeze-dried powder precursors and characterized by XRD, TG/DTA, SEM, electrical and electrochemical measurements. Pellets with different density were obtained by sintering at temperatures between 900 and 1100degreesC to obtain nearly dense samples with grain sizes in the range 1-8 mum. The electrical conductivity was measured using impedance spectroscopy. The capacitance and relaxation frequencies of the main contributions to the spectra were used to ascribe the contributions of grain interiors and internal interfaces, and their temperature dependence. A coulometric titration technique was used to evaluate the change of oxygen stoichiometry under moderately reducing conditions, and to estimate the stability limits under strongly reducing conditions. An ion-blocking method was used to evaluate the onset of n-type conductivity, and a combination of these results with total conductivity measurements was used to obtain the ionic transport number. A combination of oxygen stoichiometry changes and ion-blocking results was used to obtain estimates of mobility.
publisher	SPRINGER
issn	1432-8488
year published	2004
volume	8
issue	9
beginning page	638
ending page	643
digital object identifier (doi)	10.1007/s10008-004-0504-2
web of science category	Electrochemistry
subject category	Electrochemistry
unique article identifier	WOS:000223022400011