铁电-铁磁多铁性脉冲形成线特性

Output performance of ferroelectric-ferromagnetic multiferroic pulse forming line

对"多铁性"脉冲形成线输出特性进行了研究。利用镍锌铁氧体-钛酸钡陶瓷复合多铁性材料制作了脉冲形成线。在不同的磁回路条件下得到了不同脉冲宽度的电脉冲方波,其中以高磁导率材料组合成的闭合磁回路得到了脉冲宽度约201 ns的方波输出。推算出脉冲形成线的相对介电常数接近2 000,相对磁导率大于1.4。基于有效磁导率的概念,分析了多铁性脉冲形成线几何构型对脉冲输出特性的影响。分析表明:平板状"多铁性脉冲形成线"的有效磁导率不仅取决于平板介质的磁导率,还取决于周围介质的磁导率,因而有效磁导率通常较小,其输出表现出明显的铁电性而只有"弱"的铁磁性;相比之下,同轴结构的"多铁性脉冲形成线"具有更高的有效磁导率,其输出可同时表现出强的铁电性和铁磁性,即更明显的"多铁性"。"多铁性脉冲形成线"有可能在紧凑型脉冲功率系统中获得应用。

Output performance of multiferroic pulse forming lines（PFLs） were investigated. The multiferroic PFLs were fabricated by utilizing （Ni, Zn） ferrite-BaTiO3 ceramics composites. Square output waveforms with different widths were acquired under the conditions of different magnetic circuit schemes. With ＂closed＂ magnetic circuit scheme formed by high permeability materials, the FWHM of the output waveform is 201 ns. Relative permittivity coefficient approaching 2 000 and relative permeability coefficient more than 1.4 are calculated respectively. The impact of multiferroic PFL＇s topology on output characteristics is analysed based on the concept of effective permeability. As the parallel plate multiferroic PFL is concerned, effective permeability is determined not only by the permeability of slab medium but also by the permeability of environmental medium. Thus, the effective permeability coefficient of the parallel plate PFL is usually low, and the output shows prominent ferroelectricity but poor ferromagneticity. On the other hand, the coaxial multiferroic PFL possesses higher effective permeability so that its output shows both prominent ferroelectricity and ferromagneticity, namely multiferroicity. The multiferroic PFL is expected to be used in compact pulse power equipment.