Magnetic and dielectric properties of Aurivillius phase Bi6Fe2Ti3−2xNbxCoxO18 (0 ≤ x ≤ 0.4)
Magnetic and dielectric properties of Aurivillius phase Bi6Fe2Ti3−2xNbxCoxO18 (0 ≤ x ≤ 0.4)
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DOI：
10.1063/1.4865422
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发表时间：
2014-02
影响因子：
4
通讯作者：
Baoling Yuan;J. Yang;Jizu Chen;X. Zuo;L. Yin;X. Tang;Xuming Zhu;J. Dai;Wen-li Song;Y. Sun
中科院分区：
文献类型：
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作者：
Baoling Yuan;J. Yang;Jizu Chen;X. Zuo;L. Yin;X. Tang;Xuming Zhu;J. Dai;Wen-li Song;Y. Sun
我们研究了Bi 6 Fe 2 Ti 3 − 2xNbxCoxO 18（0 ≤ x ≤ 0.4）的结构、磁性和介电性质。与Bi 6 Fe 2 Ti 3 O 18中的顺磁行为相比，在Nb和Co共掺杂的样品中观察到室温铁磁性。Bi 6 Fe 2 Ti 3 − 2xNbxCoxO 18的铁磁性可以理解为铁基和钴基亚晶格通过Dzyaloshinsky-Moriya相互作用的反铁磁耦合的自旋倾斜。此外，在Ti位掺杂Co可以显着提高铁磁居里温度相比，在Aurivillius化合物中的Co替代Fe。Bi 6 Fe 2 Ti 3 − 2xNbxCoxO 18（0.1 ≤ x ≤ 0.4）的介电损耗呈现弛豫过程。在0.1 ≤ x ≤ 0.3的样品中有相当大的激活能，说明弛豫过程不是由于陶瓷内部氧空位的热运动引起的。
We investigate the structural, magnetic, and dielectric properties of Bi6Fe2Ti3−2xNbxCoxO18 (0 ≤ x ≤ 0.4). The room-temperature ferromagnetism is observed in the Nb and Co co-doped samples compared with the paramagnetic behavior in Bi6Fe2Ti3O18. The ferromagnetism in Bi6Fe2Ti3−2xNbxCoxO18 can be understood in terms of spin canting of the antiferromagnetic coupling of the Fe-based and Co-based sublattices via Dzyaloshinsky-Moriya interaction. Moreover, doping Co at Ti sites can significantly enhance the ferromagnetic Curie temperature compared with the substitution of Co for Fe in the Aurivillius compounds. The dielectric loss of Bi6Fe2Ti3−2xNbxCoxO18 (0.1 ≤ x ≤ 0.4) exhibits a relaxation process. The rather large activation energy in the 0.1 ≤ x ≤ 0.3 samples implies that the relaxation process is not due to the thermal motion of oxygen vacancies inside ceramics.