Lanthanoid Manganites

At higher temperatures, the ordering forces involved in the double exchange mechanism are disrupted by thermal agitation. Eventually this overcomes the 

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Lanthanoid manganites, such as LaMnOj, NdMnOj and GdMnOj, are of potential value in solid oxide fuel cell cathodes. However, many of these phase show thermal contraction because of the diminishing Jahn-Teller distortion of the Mtf " cations as the temperature is increased. Such effects tend to rule out these materials for real cell applications, although A- and B-site substitution, as demonstrated for PbTiOj earlier, can ameliorate the problem. 

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