Manganite films

Because of surface contributions as well as due to interface strains, the magnetostriction of thin films is expected to be different from that observed in bulk materials. Motivated by this observation and by possible technical applications of thin films of manganites and cobaltites, we decided to present in this paper mostly results of investigations of magnetostrictive effects in thin films. It has to be mentioned that no data exist in the literature on magnetostriction of cobaltite thin films. 

Figure 2 shows both longitudinal and transversal magnetoelastic stresses in manganite Lao.67Cao.33Mn03 films, with respect to the direction of the magnetic field. 

Materials with colossal magnetoresistance for application in different types of sensors in manganites in particular were addressed in talks by I. Troyanchuk and V. Shah (Magnetism of multilayered magnetic films). 

Zhang, L., Israel, C., Biswas, A., Greene, R. L. k de Lozanne, A. 2002 Direct observation of percolation in a manganite thin film. Science 298, 805-807. (doi 10.1126/science.l077346)... 

Haghiri-Gosnet A-M., Renard J.-P. CMR manganites physics, thin films and devices, J. Phys. D Appl. Phys., 2003, v.36, p.R127-R150. 

The electrochemical cell, as shown schematically in Fig. 1, consists of gas-tight ceramic electrolyse in the form of tubes, discs, planar substrates, or thick films which is sandwiched by precious metal like platinum or silver as electrodes. Both electrodes are in close contact with two separate gas compartments. Such cells often modified by other electrode materials like electric conducting oxides (chromites, manganites) are commonly used as gas sensors, fuel cells, and electrolysis cells. Yttria-stabilized zirconia (YSZ Zro.84To.i6< i.92) as oxide ionic conductor is widely used as an electrolyte. 

Tebano, A., Balestrino, G., Boggio, N.G., Aruta, C., Davidson, B., and Medaglia, P.G. (2006) High-quality in situ manganite thin films by pulsed laser deposition at low background pressures. Eur. Phys. J B, 51, 337-340. 

Shimizu, Y. and Murata, T. (1997) Sol-gel synthesis of perovskite-type lanthanum manganite thin films and fine powders using metal acetylacetonate and poly(vinyl alcohol). J. Am. Ceram. Soa, 80 (10), 2702-2704. 

Tip-based oxidation experiments were first performed on Si(lll) and polycrystaline tantalum faces. - Since then a large number of materials have been locally oxidized, such as compound 111-V semiconductors silicon carbide several metals such as titanium, tantalum, aluminum, molybdenum, nickel, and niobium perovskite manganite thin films dielectrics such as silicon nitride... 

Baythoun M.S.G., Sale F.R. Production of strontium-substituted lanthanum manganite perovskite powder by the amorphous citrate process. J. Mater. Sci. 1982 17 2757-2769 Bernard M.I.B., Soledade L.E., Santos I.A., Leite E.R., Longo E., Varela J.A. Influence of the concentration of 86203 and the viscosity of the precursor solution on the electrical and optical properties of Sn02 thin films produced by the Pechini method. Thin Solid Films 2002 405 228-233... 

We took advantage of the dispersibility of Pd Ce02 core-shell structures to deposit them into the porous scaffold of SOFC materials as anode catalysts in order to enhance the thermal stability of these materials. The porous scaffolds were composed of yttrium-stabilized zirconia (YSZ) covered with a film of the conductive oxide lanthanum strontium chromium manganite (LSCM). For comparison of the activity and thermal stability, we prepared other electrodes that were identical except that the catalyst was simply Pd (from Pd(II) nitrate) in one case and a mixture of Pd and CeOg (from Pd(II) and Ce(III) nitrate salts) in the other. All the samples were first calcined at 700 °G to remove any by-products and to stabilize the materials. Then, accelerated aging tests were performed by calcining the samples at 900 °C for 2 hours. Initially we tested all the formulations in symmetric cells, e.g. cells where the anode and cathode materials are the same. The corresponding Nyquist plots are shown in Fig. 7.12(a). 

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