Ceramic method, perovskite preparation

The M-NM transition has been studied in powder samples (prepared by the ceramic method) of the series of perovskite oxides Lai- TiOs with 0 temperature dependencies to the magnetic susceptibility (Fig. 7.6a) and electrical resistivity (Fig. 7.6b) for different compositions, as well as the cell parameters for the phases ... 

Solid-solid reactions are the basis of the most frequently used procedures for preparing mixed oxides, especially when the surface areas of the resulting solids are not an important parameter. Indeed, these high-temperature methods are essential for preparing perovskites with special morphologies, such as monocrystals or thin layers. Because this kind of method is most frequently used for the preparation of ceramic materials, it is usually referred to as the ceramic method. ... 

Wachowski et al. (42,43) have compared the surface areas of a series of eight perovskites prepared by different methods ceramic (<2.4 m2/g), coprecipitation as oxalates (4.5-11 m2/g), explosion (21-37 m2/g), and freeze-drying (22-39 m2/g). Again, surface areas clearly depended on the minimum temperature necessary for complete reaction. The greatest losses in surface area by sintering were observed in the temperature range 700-930°C. 

Moure C., Gutierrez D., Tartaj J., Duran P. Synthesis, sintering and electrical properties of YNio.33Mno.67O3 perovskite prepared by a polymerized method. J. Eur. Ceram. Soc. 2003 23 729-736... 

A continuous process based on hydrodynamic cavitation can be employed to prepare a wide variety of metal oxides in grain sizes of 1 -10 nm, such as iron oxide, bismuth molybdate, perovskites, platinum-loaded zeolite, and other ceramics and superconductors [170]. The method uses a microfluidiser for mechanically generating hydrodynamic cavitation and the internal pressure of the liquid media is elevated from ambient pressure to between 1000 to 25 000 psi. 

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