压电层体积分数对BTO基复合薄膜磁电性能的影响

Effect of Volume Fraction of Piezoelectric Layer on Magnetoelectric Properties of BTO-based Composite Films

基于力学参数模型研究了NFO/BTO层状复合薄膜的磁电效应,发现当压电相的体积分数约为0. 47时,磁电耦合性能最好。通过脉冲激光沉积法在掺0. 7%Nb的(001)-STO衬底上生长了不同体积分数比的2-2型NFO/BCZT异质结构的磁电复合薄膜。XRD结果表明:NFO/BCZT磁电复合薄膜均为(00l)择优取向生长结构。通过锁相技术测试了NFO/BCZT复合薄膜的磁电耦合系数,测试结果表明压电相体积稍大于铁磁层体积时,磁电性能最佳。实验结果与理论结果存在一定差异,主要是由于材料实际参数与计算所用参数有差异、界面的非理想耦合无法得到准确的k值以及复合薄膜微观结构、应力等影响。

The magnetoelectric effect of layered NFO/BTO composite films was studied based on the mechanical parameter model. It was found that the magnetoelectric coupling performance was best when the volume fraction of piezoelectric phase was about 0. 47. The 2-2 NFO/BCZT films with different volume fraction ratios were grown by pulsed laser deposition with 0. 7% Nb( 001)-STO substrates. The results of XRD show that NFO/BCZT composite films are( 00 l) preferentially grown.The magnetoelectric coupling coefficient of the NFO/BCZT composite film was measured by a lock-in amplifier,the results show that the magnetoelectric performance is best when the volume of piezoelectric phase is slightly larger than that of piezoelectric phase. There are some differences between experimental results and theoretical results,which be mainly due to the difference between the actual parameters of the material and the parameters used in the calculation,the failure to obtain accurate k values due to the non-ideal coupling of the interface,and magnetoelectric effect is affected by microstructure and stress of thin films.