Lanthanum ferrites

Single-phase perovskite MIECs such as Sr-doped lanthanum cobaltite (LSC), lanthanum ferrite (LSF), lanthanum cobalt ferrite (LSCF) and samarium cobaltite (SSC), and Ca-doped lanthanum ferrite (LCF) [13] are sometimes used alone in SOFC cathodes, as depicted in the lower right-hand comer of Figure 6.1, but combining an... 

Wang WG and Mogensen M. High-performance lanthanum-ferrite-based cathode for SOFC. Solid State Ionics 2005 176 457 -62. 

Simner, S.P., Bonnett, J.F., Canfield, N.L., Meinhardt, K.D., Sprenkle, V.L., and Stevenson, J.W., Optimized lanthanum ferrite-based cathodes for anode-supported SOFCs, Electrochemical Solid-State Letters, 2002, 5, A173. 

M.A. Alario-Franco, M.J.R. Henche, M. Vallet, J.M.G. Calbet, J.C. Grenier, A. Wattiaux and P. Hagenmuller, Microdomain texture and oxygen excess in the calcium-lanthanum ferrite CaaLaFesOs. /. Solid State Chem., 46 (1983) 23-40. 

J.M. Gonzales-Calbet, M. Parras, M. Vallet-Regi and J.C. Grenier, Anionic vacancy distribution in reduced barium-lanthanum ferrites BaxLai-xFe03-x/2 (1/2 < x < 2/3). /. Solid State Chem., 92 (1991) 100-115. 

C., Mertens, J., and Tietz, F. (2010) Various lanthanum ferrite-based cathode materials with Ni and Cu substitution for anode-supported solid oxide fuel cells. J. Fuel Cell Sci. Technd., 7, 061017-1-061017-4. 

Ammonia oxidation for the manufacture of NO (an intermediate in nitric acid production) is carried out in an oxidation reactor incorporating a Ca- and Sr-substituted lanthanum ferrite perovskite membrane. NO selectivity of the order of 98% is achieved by the membrane, while N2 is rejected completely. The membrane reactor obviates the need for expensive noble metal catalysts and does not produce environmentally harmful N2O. 

Perez-Ramirez, J. and Vigeland, B. (2005). Lanthanum ferrite membranes in ammonia oxidation. Opportunities for pocket-sized nitric acid plants. Catalysis Today, Vol. 105, pp. 436-442. 

Adequate electronic and ionic conductivity. Though the conductivities are adequate, the ionic conductivity of LSM is significantly lower than YSZ, and its electronic conductivity is a fraction of any of the metals or even of lanthanum chromite. Consequently, ionic and electronic resistance can become a significant factor, especially in cell designs that incorporate long current paths through the cathode. For lower-temperature cells, conductivity of LSM is inadequate, and other materials, such as strontium-doped lanthanum ferrite (LSF) are considered. 

Abazari, R., Sanati, S., and Saghatforoush, L.A. (2014) A unique and fecile preparation of lanthanum ferrite nanoparticles in emulsion nanoreactors morphology, structure, and efficient photocatalysis. Mater. Sci Semicon. Proc., 25, 301-306. 

Alario-Franco, M.A., Gonzalez-Calbet, J.M., and Vallet-Regi, M.J. Brownmillerite-type microdomains in the calcium lanthanum ferrites Ca cLai y Fe03, 1.2/3 < X <. Solid State Chem. 1983, 49, 219-231. 

Simner SP, Bonnett JR, Canfield NL et al (2003) Development of lanthanum ferrite SOFC cathodes. J Power Sources 113 1-10... 

For lanthanum ferrite and cobaltites, the energies of the oxygen adsorption were found to be comparable with those in lanthanum manganite (Table 5). 

Nowadays lanthanum ferrites and chromiiun doped lantlianide aluminates with perovskite structure are used as ceramic pigments because they have colorimetric properties, high thermal stability, line particle size and chemical resistance. Also, the ferrites have interesting magnetic properties and the aluminates are materials having photoluminescence properties. 

The raw materials used in the synthesis of LnFeOs (Ln = La, Ho) were Ln203 oxides Aldrich and Fe203 Baker R.A. This ferrites were prepared mixing the starting materials in stoichiometric relations 1 1 in an agate mortar, after were fired in an electric furnace at 900°C, 950°C by 20h each one and 1000°C, in the case of lanthanum ferrite by 24h and in the case of holmium ferrite by 30h. LnFeOs (Ln = Nd, Sm, Er) were synthesized by the precursor method. (See forward Precursor method)... 

Fig. 11 Cross-sectional SEM micrograph of MS-SOFC fabricated by Ceres FSS/Ni-CGO/CGO/CGO-Lanthanum ferrite [25]. Dense CGO is obtained after firing at 1000 °C. Reproduced here with kind permission from ASM International 2004...

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