Fig. 1. XRD patterns of BNFNT-x (x = 0.00, 0.10, 0.20, 0.25 and 0.30) at room temperature. 室温下BNFNT-x (x = 0.00, 0.10, 0.20, 0.25和0.30)的XRD图谱

Fig. 2. SEM micrographs of fresh fracture surfaces of BNFNT-x (x = 0.00, 0.10, 0.20, 0.25 and 0.30) samples. BNFNT-x (x = 0.00, 0.10, 0.20, 0.25和0.30)样品断面的SEM图像

Fig. 3. (a) Raman spectra of BNFNT-x at room temperature; (b) effect of Nd content on Raman peaks associated with BiO layers in BNFNT-x samples. (a) 室温下BNFNT-x样品的拉曼谱; (b) Nd含量对BNFNT-x样品中与BiO层相关的拉曼峰的影响

Fig. 4. Ferroelectric hysteresis loop of BNFNT-x ceramic samples at room temperature. 室温下BNFNT-x陶瓷样品的电滞回线

Fig. 5. (a) The 2P_r-E curves of BNFNT-x samples; (b) dependence of 2P_rof BNFNT-x ceramics on Nd content x under the electric filed about 140 kV/cm; (c) dependence of 2P_r of BNFNT-x ceramics on Nd content x under the electric filed about 190 kV/cm. (a) BNFNT-x 样品2P_r-E曲线; (b)电场约为140 kV/cm下Nd含量对2P_r的影响; (c)电场约为190 kV/cm下Nd含量对2P_r的影响

Fig. 6. Dielectric loss peak with the measurement temperature from 120 to 1000 K at the frequency of 27.17 kHz. Inset is the corresponding enlarge part of BNFNT-x sample under the temperature from 200 to 400 K. 27.17 kHz频率下120—1000 K温度范围内所测量的介电损耗峰(插图为BNFNT-x样品200—400 K的放大部分)

Fig. 7. (a)−(e) Dielectric loss peak with the measurement frequencies from 1 kHz to 492.2 kHz (inset is the corresponding activation energy of BNFNT-x sample): (a) Bi₆Fe_1.4Ni_0.6Ti₃O₁₈; (b) Bi_5.9Nd_0.1Fe_1.4Ni_0.6Ti₃O₁₈; (c) Bi_5.8Nd_0.2Fe_1.4Ni_0.6Ti₃O₁₈;(d) Bi_5.75Nd_0.25Fe_1.4Ni_0.6Ti₃O₁₈; (e) Bi_5.7Nd_0.3Fe_1.4Ni_0.6Ti₃O₁₈; (f) dependence of activation energy of BNFNT-x ceramics on Nd content x. (a)—(e)测量频率为1—492.2 kHz时BNFNT-x样品的介电损耗峰 (插图为BNFNT-x样品相应的激活能)(a) Bi₆Fe_1.4Ni_0.6Ti₃O₁₈; (b) Bi_5.9Nd_0.1Fe_1.4Ni_0.6Ti₃O₁₈; (c) Bi_5.8Nd_0.2Fe_1.4Ni_0.6Ti₃O₁₈; (d) Bi_5.75Nd_0.25Fe_1.4Ni_0.6Ti₃O₁₈; (e) Bi_5.7Nd_0.3Fe_1.4Ni_0.6Ti₃O₁₈; (f) BNFNT-x样品Nd含量对激活能的影响

Fig. 8. (a) At room temperature, magnetic hysteresis of BNFNT-x samples (inset is the enlarged central part of the M-H curve); (b) dependence of 2M_sof BNFNT-x on the Nd content. (a)室温下BNFNT-x样品的磁滞回线 (插图为中部放大图像); (b) BNFNT-x样品2M_s随Nd含量的变化

Fig. 9. FC and ZFC magnetization curves of the BNFNT-x sample: (a) x = 0.00; (b) x = 0.10; (c) x = 0.20; (d) x = 0.25; (e) x = 0.30. BNFNT-x样品的FC和ZFC磁化曲线　(a) x = 0.00; (b) x = 0.10; (c) x = 0.20; (d) x = 0.25; (e) x = 0.30

Fig. 10. (a) Electron spectra of Bi in BNFNT-x samples; (b) electron spectra of Fe in BNFNT-x samples. (a) BNFNT-x样品中Bi的电子能谱图; (b) BNFNT-x样品中Fe的电子能谱图