Effect of kinetic growth parameters on leakage current and ferroelectric behavior of BiFeO3 thin films
Effect of kinetic growth parameters on leakage current and ferroelectric behavior of BiFeO3 thin films
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DOI：
10.1063/1.3254190
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发表时间：
2009-11
影响因子：
3.2
通讯作者：
V. Shelke;V. Harshan;S. Kotru;Arunava Gupta
中科院分区：
文献类型：
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作者：
V. Shelke;V. Harshan;S. Kotru;Arunava Gupta
采用脉冲激光沉积技术，在相同的热力学和可变的动力学条件下，在(100)取向的SrTiO_3和掺Nb的SrTiO_3衬底上生长了BiFeO_3外延薄膜。生长动力学随激光通量和脉冲重复频率的变化对薄膜的结构和磁性能影响很小。然而，薄膜的微观结构发生了很大的变化，对于50 nm厚的薄膜，初始的岛状生长模式接近于阶梯流型生长，粗糙度从12.5 nm降低到1.8 nm。相应地，室温下的漏电流密度持续下降了近四个数量级。低漏电流薄膜的主要机制是空间电荷限制导电。这些结果表明，通过控制动力学生长参数可以很好地解决漏电流问题。在这种情况下，可以施加强电场，最大偏振值可达10~3μC/cm~2。
Epitaxial BiFeO3 thin films have been grown on (100)-oriented SrTiO3 and Nb-doped SrTiO3 substrates using the pulsed laser deposition technique under identical thermodynamic and variable kinetic conditions. The variation of growth kinetics through laser fluence and pulse repetition rate had minimal effect on the structure and magnetic properties of films. However, large changes were observed in the microstructure, with initial island growth mode approaching toward step-flow type growth and roughness reducing from 12.5 to 1.8 nm for 50 nm thick film. Correspondingly, the leakage current density at room temperature dropped consistently by almost four orders of magnitude. The dominant mechanism in low leakage current films was space-charge-limited conduction. These findings suggest that the issue of leakage current can be dealt favorably by controlling kinetic growth parameters. The application of high electric field and observation of maximum polarization value up to 103 μC/cm2 could be possible in these sa...