中文摘要：

采用传统的固相烧结工艺制备出Bi5Fe0.7Ni0.3Ti3O15（BFNT）多铁陶瓷样品,研究镍离子基团的植入对材料的微观结构、磁性能和电性能的影响.X射线衍射谱显示BFNT样品的4层Aurivillius相已形成.室温下,BFNT样品具有铁磁性,其剩余磁化（2Mr）和矫顽场（2Hc）分别为0.086 A.m2.kg-1和18.5 kA.m-1.样品磁性的增强可能来源于局域的Fe—O—Ni的耦合.介电温度谱的测试结果表明：与Bi5FeTi3O15（BFTO）比较,BFNT的铁电相变温度降低,低温段的介电峰具有明显的弛豫特征,该弛豫可能与磁有关.室温下,当外加电场为24.5 MV.m-1时,样品的剩余极化（2Pr）和矫顽场（2Ec）分别为0.069 C.m-2和14.3 MV.m-1.

英文摘要：

Bi5Fe0.7Ni0.3Ti3O15（BFNT） multiferroic ceramics are prepared using solid-state reaction.Effects of embedded Ni3＋ ions in the Bi5FeTi3O15（BFTO） on the microstructure,magnetic and electrical properties are investigated.X-ray diffraction patterns show that the four-layer Aurivillius phase is formed successfully.BFNT shows remarkable ferromagnetism at room temperature with remanent magnetization（2Mr） of 0.086 A·m2·kg-1 and coercive field（2Hc） of 18.5 kA·m-1.The improvement of magnetic properties may come from local coupling of Fe—O—Ni.The temperature dependence of dielectric permittivity of BFNT shows that the ferroelectric curie temperature shifts to lower temperature comparing to that of BFTO and the dielectric anomalies at low temperature exhibit obvious relaxation characteristics,which might be related to magnetism.The remanent polarization（2Pr） and the coercive field（2Ec） of the BFNT sample under an applied field of 24.5 MV·m-1 are measured to be 0.069 C·m-2 and 14.3 MV·m-1,respectively.