MULTIFERROIC BiFeO₃ FILMS: CANDIDATE FOR ROOM TEMPERATURE MICRO BIOSENSOR

ABSTRACT

We formed BoFeO₃ (BFO) thin films by chemical solutions deposition on Pt/Ti/SiO₂/Si(100) structures and achieved low leakage current density at room temperature. The XPS spectrum confirmed that the valance state of Fe in our BFO thin films was mainly Fe³⁺, which is associated with low leakage current density in BFO thin films. Due to improved breakdown characteristic of the films saturated polarization hysteresis loops with remanent polarization of 75 μC/cm² were measured at a frequencies of 20 kHz. The achieved piezoelectric coefficient d₃₃ was approximately 60 pm/V, showing that the BFO films have potential for sensing devices and they can covert mechanical vibration energy into electrical energy, which may be utilized for micro biosensors.