Effect of Barium-to-Strontium on Leakage Current Mechanism of Sol-Gel Ba_xSr_1-xTiO₃ Thin Films

Abstract

Ferroelectric barium strontium titanate (BaxSr1-xTiO3) thin films with different Ba content have been fabricated as MFM configuration using sol-gel technique. The effect of barium-to-strontium ratio on the leakage current mechanism of BaxSr1-xTiO3 thin films has been investigated. The results show that the leakage current density increases as Ba content increases, which attributed to the grain size effect. The leakage current for the tested films has been studied using log (J) vs log (E) plane, which shows three distinguished linear regions. These regions have been characterized using power law () to find that: the region at low electric fields (E < 20 KV/cm) is controlled by Ohmic conduction and the other two regions (E > 20 KV/cm) are due to space charge limited conduction, which is also confirmed via modified Langmuir-Child law. In addition, it is observed that at high electric fields region (E > 1.29×105 V/m) the films show Schottky emission (SE) and PooleFrenkel (PF) emission mechanisms.