Sinterability, reducibility, and electrical conductivity of fast oxide-ion conductors La1.8R0.2MoWO9 (R=Pr, Nd, Gd and Y)

The first characterization of cubic Nd3+-doped mixed La2MoWO9 in micro-crystalline powders and translucent micro-ceramics

“…Consequently, this makes it possible to obtain more homogenous micropowders and translucent ceramics. It is important to mention that the previous assays performed by Ge et al for La 1.8 R 0.2 MoWO 9 (R = Pr, Nd, Gd and Y) 35 did not result in transparent ceramics of different colours, i.e., pale yellow, creamy white, green or blue gray. 3% Nd 3+ -doped La 2 MoWO 9 .…”

“…The comparison of the XRD patterns of the b cubic phase (ICSD#420672) with that of the a monoclinic phase (ICSD#174279) suggests that the positions of the diffraction lines for both phases are the same. The patterns are similar because the structure of a-La 2 Mo 2 O 9 is derived from the b-phase by oxide ion ordering of the lattice distortions 35.…”

“…In the literature, there are a few articles in which sintered ceramics with a high density (∼98%) have been obtained and their structural stability under an H 2 /Ar reductive atmosphere investigated. 33–36 All the available studies confirmed that the substitution of 50% of molybdenum with the W ion stabilizes the cubic phase and protects it from decomposition. However, these materials were used only for electrical conductivity studies and the fabrication of transparent ceramics was not the subject of the research; hence, they lack information on the transparency of the samples.…”

Electric Relaxation Studies on La2−xNdxMo2O9Oxide-Ion-Conductor Ceramics

“…The cell parameters were refined by a least-squares procedure using the Powder X program; the values obtained are displayed in Table I. Ge et al 13 systematically studied the effect of R (R = Pr, Nd, Gd, Y) substitution on the crystal structure of La 2−x R x Mo 2 O 9 and found that the cell parameter of La 2−x R x Mo 2 O 9 decreases in the order Pr 3+ (0.118 nm) > 3+ is smaller than that of La 3+ (0.122 nm at CN = 9). 13 The cell parameter of β-La 2 Mo 2 O 9 is 0.71571(3) nm, and this value decreases to 0.71300(9) nm when 50% Nd is substituted at the La sites.…”

“…10 Such reports inspired us to explore the intrinsic defects and related properties of Nd 3+ -doped La 2 Mo 2 O 9 , although the effect of Nd doping on the ionic conductivity of La 2 Mo 2 O 9 has been revealed in previous publications. [11][12][13] In this study, we synthesized La 2−x Nd x Mo 2 O 9 (x = 0.4, 0.6, 0.8, 1.0) ceramics via a sol-gel method and systematically investigated their electrical properties via dielectric, impedance, and electrical modulus spectroscopies. We believe that the Nd 3+ -doped lanthanum molybdate material, characterized by a relatively low operating temperature, comparatively high ionic conductivity, and environmentally z E-mail: zhiguo@fjirsm.ac.cn; xthuang@phy.ccnu.edu.cn friendly properties, holds great promise for use as components of fuel cells, oxygen pumps, oxygen sensors, and oxygen-permeable membrane catalysts.…”