Structural, magnetic and dielectric properties of the Aurivillius phase Bi6Fe2−xMnxTi3O18 (0 ≤ x ≤ 0.8)
Structural, magnetic and dielectric properties of the Aurivillius phase Bi6Fe2−xMnxTi3O18 (0 ≤ x ≤ 0.8)
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DOI：
10.1039/c4ra06843b
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发表时间：
2014-09
期刊：
影响因子：
3.9
通讯作者：
X. Zuo;Jie Yang;B. Yuan;D. Song;Xianwu Tang;Kejun Zhang;Xuebin Zhu;W. Song;J. Dai;Yuping Sun
中科院分区：
文献类型：
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作者：
X. Zuo;Jie Yang;B. Yuan;D. Song;Xianwu Tang;Kejun Zhang;Xuebin Zhu;W. Song;J. Dai;Yuping Sun
采用传统固相反应法合成了n = 5的Aurivillius相Bi 6 Fe 2 − xMnxTi 3 O 18（BFMTO）（0 ≤ x ≤ 0. 8）陶瓷。所有样品都可以用具有空间群B2cb的正交结构索引。磁性测量结果表明，这些陶瓷主要是顺磁性的，存在短程反铁磁相互作用和弱铁磁有序状态，这意味着在BFMTO陶瓷中通过Mn取代n = 5 Aurivillius相中的Fe，可能无法实现基于Goodenough-Kanamori规则预测的Fe 3 +-O-Mn 3 + 180°铁磁超交换相互作用. x = 0.3和0.4样品的介电损耗证明了弛豫过程，并且相当大的激活能（x = 0.3样品为2.63 eV，x = 0.4样品为2.10 eV）意味着该弛豫过程不是由于氧空位的热运动。0.5 ≤ x ≤ 0.8的样品表现出顺电-铁电相变，铁电居里温度随Mn掺杂量的增加而降低。
The n = 5 Aurivillius phase ceramics Bi6Fe2−xMnxTi3O18 (BFMTO) (0 ≤ x ≤ 0.8) were synthesized with a conventional solid-state reaction method. All samples can be indexed with an orthorhombic structure with the space group B2cb. The magnetic measurements indicate that these ceramics are predominantly paramagnetic with the presence of short-range antiferromagnetic interactions and a weak ferromagnetic ordering state, implying that the predicted Fe3+–O–Mn3+ 180° ferromagnetic superexchange interaction based on the Goodenough–Kanamori rule might not be achieved in BFMTO ceramics through Mn substitution for Fe in the n = 5 Aurivillius phase. The dielectric loss of the x = 0.3 and 0.4 samples demonstrates the relaxation process and the rather large activation energy (2.63 eV for the x = 0.3 sample and 2.10 eV for the x = 0.4 sample) implies that this relaxation process is not due to the thermal motion of oxygen vacancies. The 0.5 ≤ x ≤ 0.8 samples exhibit a paraelectric–ferroelectric phase transition and the ferroelectric Curie temperature decreases upon increasing the doping level of Mn.