Search for long-range ferromagnetism: Charge-spin co-doped Ba1−x−yLax+yTi1−xMxO3 (M = Cr, Fe, and Co)
Search for long-range ferromagnetism: Charge-spin co-doped Ba1−x−yLax+yTi1−xMxO3 (M = Cr, Fe, and Co)
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DOI：
10.1063/1.4790869
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发表时间：
2013-02
影响因子：
3.2
通讯作者：
D. Shao;J. Yang;H. Jian;Xuming Zhu;Y. Sun
中科院分区：
文献类型：
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作者：
D. Shao;J. Yang;H. Jian;Xuming Zhu;Y. Sun
我们研究了电荷自旋共掺杂Ba1−x−yLax+yTi1−xMxO3（M = Cr，Fe，and Co）的结构、磁性和电学性质。对于Ba1−x−yLax+yTi1−xCrxO3，载流子掺杂诱导短程铁磁性，我们发现这些化合物中存在较大的负磁阻。然而，对于Ba1−x−yLax+yTi1−xMxO3（M = Fe和Co），磁性似乎不与电荷载流子耦合。Ba1−x−yLax+yTi1−xCrxO3的输运性质可以用三维变程跳跃模型来描述，该模型暗示了巡游电荷载流子，而几乎所有的Ba1−x−yLax+yTi1−xMxO3（M = Fe和Co）样品都表现出高电阻率。只有巡游载流子才能增强两个孤立磁性离子的耦合。因此，在所研究的系统中几乎没有长程铁磁性。
We investigate the structural, magnetic, and electrical properties of charge-spin co-doped Ba1−x−yLax+yTi1−xMxO3 (M = Cr, Fe, and Co). For Ba1−x−yLax+yTi1−xCrxO3, carrier doping induces short-range ferromagnetism, and we find a large negative magnetoresistance in these compounds. However, for Ba1−x−yLax+yTi1−xMxO3 (M = Fe and Co), the magnetism does not seem to couple with the charge carriers. The transport properties of Ba1−x−yLax+yTi1−xCrxO3 can be described by a three-dimensional variable-range-hopping model that implies itinerant charge carriers, whereas almost all the samples of Ba1−x−yLax+yTi1−xMxO3 (M = Fe and Co) exhibit high resistivity. It is known that only the itinerant charge carriers can enhance the coupling of two isolated magnetic ions. Therefore, there is almost no long-range ferromagnetism in the studied system.