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As the oxidation and chromium volatilization of chromia-forming alloy interconnects can cause Solid oxide fuel cells ( SOFC) cathode poisoning and cell degradation, spinel coatings like Mn1.5 Co1.5 O4 have been applied as a barrier to oxygen and chromium diffusion. To evaluate their long-term stability, the properties of the reaction layer between the Mn1.5 Co1.5 O4 coating and Cr2 O3 scale formed on the alloy surface need to be characterized. Therefore, compositions of Mn1.5−0.5 x Co1.5−0.5 x Cr x O4 ( x = 0-2) were prepared to investigate their electrical properties, cation distributions, and thermal expansion behavior at high temperature. With increasing Cr content in manganese cobalt spinel oxides, the cubic crystal structure is stabilized and the electrical conductivity and coefficient of thermal expansion both decrease. The cation distributions determined from neutron diffraction show that Cr and Mn have stronger preference for octahedral sites in the spinel structure as compared with Co. [ABSTRACT FROM AUTHOR]

Epitaxial SrRu1−xSnxO3 (0 ≤ x ≤ 1) thin films were deposited on SrTiO3 (001) substrates by sequential two-target synthesis using pulsed laser deposition to achieve stable phases in this family of quaternary perovskites. The SrRu1−xSnxO3 films exhibit a good crystalline quality, a sharp interface between film and substrate, and an atomically smooth surface. A gradual expansion of the c-axis lattice parameter was observed with Sn doping serving as a means to tune chemical pressure and magnetism. With an increase in Sn doping, the resistivity of the film increased, and the ferromagnetism decreased. These results illustrate use of lattice engineering, e.g., tuning of c-axis lattice parameter with chemical doping, to control electronic and magnetic properties of epitaxial thin films for applications in oxide electronics. [ABSTRACT FROM AUTHOR]

Magnetoelectric multiferroicity is not expected to occur in a cubic perovskite system because of the high structural symmetry. By versatile measurements in magnetization, dielectric constant, electric polarization, neutron and x-ray diffraction, Raman scattering, as well as theoretical calculations, we reveal that the A-site ordered perovskite LaMn3Cr4O12 with cubic symmetry is a novel spin-driven multiferroic system with strong magnetoelectric coupling effects. When a magnetic field is applied in parallel (perpendicular) to an electric field, the ferroelectric polarization can be enhanced (suppressed) significantly. The unique multiferroic phenomenon observed in this cubic perovskite cannot be understood by conventional spin-driven microscopic mechanisms. Instead, a nontrivial effect involving the interactions between two magnetic sublattices is likely to play a crucial role. [ABSTRACT FROM AUTHOR]