We have prepared polycrystalline samples of Sr3YCo4O10.56, Sr2.4Ca0.6YCo4O10.54, and Sr3YCo3.76Mn0.24O10.59, and found that these materials show unusual impurity effects on their transport and magnetic properties. A tiny amount of impurities such as Mn or Ca suppresses room-temperature ferromagnetism of Sr3YCo4O10.56. With the suppression, their resistivities and thermopowers are also dramatically changed. We propose that the unusual impurity effects are caused by the suppression of orbital ordering.
|ジャーナル||Progress in Solid State Chemistry|
|号||2-4 SPEC. ISS.|
|出版ステータス||Published - 2007|
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