Bi_4−x Nd _x FeTi₂O₁₂ (BNFTO, x = 0, 0.5, 1.0, and 1.5) Aurivillius three-layered ceramics are prepared via a solid-state reaction method. The crystal structure of the compounds reveals that the compounds exhibit a major orthorhombic structure with the B2cb space group. Slight distortions in the orthorhombic unit cell and an increase in cell volume with the doping of Nd are observed. Highly dense randomly oriented plate-like nonuniform grains are observed in the micrographs of the ceramics. A decrease in energy bandgap values is noticed in Nd-doped ceramics from 2.88 to 2.18 eV. An increase in polarization values is observed with Nd doping due to the improved grain boundaries. The appearance of a weak ferromagnetic nature at low temperature followed by a decline in magnetic interaction at room temperature (RT) is observed for all compounds. The frequency and temperature variations of the dielectric constant are investigated. The frequency and temperature variations of the impedance measurements indicate that compounds exhibit non-Debye-type electrical relaxations and a negative temperature coefficient of resistance. Furthermore, single-peak relaxations are predominant for all measured samples, mainly the contribution of intragranular grain regions. This makes Nd-dopant BNFTO Aurivillius ceramics have a great research value for RT multiferroic applications.

中文翻译：

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Nd 掺杂在 Bi4Ti2FeO12 多铁性 Aurivillius 陶瓷上的结构、微观结构、介电和阻抗特性的相关性

Bi _{4− x} Nd _x FeTi ₂ O ₁₂ (BNFTO, x  = 0, 0.5, 1.0, and 1.5) 通过固相反应法制备了Aurivillius 三层陶瓷。化合物的晶体结构表明化合物具有B2cb的主要正交结构 空间群。观察到斜方晶胞的轻微变形和 Nd 掺杂导致的晶胞体积增加。在陶瓷的显微照片中观察到高度致密的随机取向的板状不均匀晶粒。Nd 掺杂陶瓷的能带隙值从 2.88 降低到 2.18 eV。由于改进的晶界，Nd 掺杂观察到极化值的增加。观察到所有化合物在低温下出现弱铁磁性质，随后在室温 (RT) 下磁相互作用下降。研究了介电常数的频率和温度变化。阻抗测量的频率和温度变化表明化合物表现出非德拜型电弛豫和电阻的负温度系数。此外，单峰弛豫在所有测量样品中占主导地位，主要是晶内晶粒区域的贡献。这使得 Nd 掺杂 BNFTO Aurivillius 陶瓷对于 RT 多铁性应用具有很大的研究价值。