Bismuth ferrite

Annenkova et al. (105) studied both the physicochemical and catalytic properties of the Bi-Fe-Mo oxide system. The X-ray diffraction, infrared spectroscopic, and thermographic measurements indicated that the catalysts were heterogeneous mixtures consisting principally of ferric molybdate, a-bismuth molybdate, and minor amounts of bismuth ferrite and molybdenum trioxide. The Bi-Fe-Mo oxide catalysts were more active in the oxidation of butene to butadiene and carbon dioxide than the bismuth molybdate catalysts. The addition of ferric oxide to bismuth molybdate was also found to increase the electrical conductivity of the catalyst. 

Other materials, such as bismuth ferrites (BiFeOs, Bi4pe209, Bi2pe409) [14] have been studied as semiconductor materials for resistive gas sensors they respond as n-type semiconductors as with typical metal oxides. The changes in conductivity of these materials are due to a volume effect. In the absence of air, sensitivities to reducing gases such as petrol, ethanol, and acetone were at least an order of magnitude lower than under similar conditions with air present. 

Poghossian A S, Abovian H V, Avakian P B, Mkrtchian S H and Haroutunian V M 1991 Bismuth ferrites new materials for semiconductor gas sensors Sensors Actuators B 4 545-9... 

A. Gajovid, S. Sturm, B. JanCar, A. Santid, K. Zagar, M. Ceh, The Synthesis of Pure-Phase Bismuth Ferrite in the Bi-Fe-O System Under Hydrothermal Conditions without a Mineralizer, J. Am. Ceram. Soc., 93, 3173-3179 (2010). 

Biasotto, G., Simoes, A.Z., Foschini, C.R., Zaghete, M.A., Varela, J.A., and Longo, E. (2011) Microwave-hydrothermal synthesis of perovskite bismuth ferrite nanoparticles. Mater. Res. Bull., 46, 2543-2547. 

The use of lead-bismuth as a primary coolant at relatively low core outlet temperature and coolant heatup allows the use of ferritic-martensitic steel EP-823 (12%Cr-Si) as a structural material for the core and steam generator. This steel was checked in practice for resistance against radiation swelling and radiation creep. 

In early patents, it was claimed that various phosphate catalysts, including calcium/nickel phosphate and bismuth/molybdate, were active. A variety of other catalysts was also introduced, including the zinc and magnesium ferrites developed by Petrotex." The best ferrite catalyst included chromium to prevent excessive catalyst reduction." PhilUps described tin oxide catalysts that were promoted with 4% phosphate and 1% lithium as well as the bismuth/phosphate catalysts that were promoted with boron or lithium compounds. 

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