Although some perovskite oxides have been shown to be stable solid oxide fuel cell (SOFC) anodes, the actual crystal structure of these materials under operating conditions is largely unknown. In this paper, the structural evolution of the SOFC anode La 0.30 Sr 0.70 Fe 0.70 Cr 0.30 O 3-δ was studied at 800 and 900 °C (similar to SOFC operating temperatures) in progressively reducing and oxidizing environments. The perovskite was shown to be stable down to a pO 2 of 10 -20 atm at 800 °C and a pO 2 of 10 -18 atm at 900 °C, at which point a spinel phase formed. Further reduction led to the formation of Fe metal. The phase separation of La 0.30 Sr 0.70 Fe 0.70 Cr 0.30 O 3-δ was also shown to be completely reversible with an increase in the partial oxygen pressure and reoxidation of the sample.

By initially depositing a sub-10 nm-thick SnO2 film, the microstructural evolution that is often considered problematic can be utilized to form Sn nanoparticles on the surface of a 3D current collector for enhanced cycling stability. The work described here highlights a novel approach for the uniform deposition of Sn nanoparticles, which can be used to design electrodes with high capacities and high-rate capabilities.

A new nonlinear optical crystal, Na 3 VO 2 B 6 O 11 , has been grown by the top-seeded solution growth method using a Na 2 CO 3 -V 2 O 5 flux. The structure of the compound was determined by single-crystal X-ray diffraction. It crystallizes in the noncentrosymmetric orthorhombic system, space group P2 1 2 1 2 1 , with cell parameters a = 7.7359(9) A ˚, b = 10.1884(12) A ˚, c = 12.5697(15) A ˚, V = 990.7(2) A ˚3, and Z = 4. Na 3 VO 2 B 6 O 11 has a three-dimensional structure consisting of hexaborate groups connected by VO 4 tetrahedra with the sodium atoms distributed in channels through out the three-dimensional network. The refractive indices have been measured by the minimum deviation technique and fit to the Sellmeier equations. Nonlinear optical measurements on the compound demonstrate that the material has second harmonic generation properties, with an efficiency approximately the same as that of KH 2 PO 4 .