Asymmetric electrical properties in Pt/Ba 0.5Sr 0.5Ti 0.99Co 0.01O 3/Nb-doped SrTiO 3 capacitors
Abstract
Ba 0.5Sr 0.5Ti 0.99Co 0.01O 3 (BSTC) thin films have been fabricated with pulsed laser deposition on Nb-doped SrTiO 3 (STN) substrate. In Pt/BSTC/STN capacitor, we systematically investigated the capacitance, leakage current and polarization versus bias voltage characteristics, and found that curves of capacitance versus voltage and leakage current versus voltage were not symmetric, and polarization hysteresis loop exhibited large relaxation of the remnant polarization at negatively poled state. A detailed analysis of capacitance data demonstrated a difference of the built-in voltage between top Pt/BSTC interface ( Vb,t=2.5 V) and bottom BSTC/STN interface ( Vb,b=1.1 V). Such different built-in voltages lead to the presence of an internal electric field, which results in asymmetric electric characteristics in Pt/BSTC/STN capacitor.
- Publication:
-
Physica B Condensed Matter
- Pub Date:
- September 2011
- DOI:
- 10.1016/j.physb.2011.06.009
- Bibcode:
- 2011PhyB..406.3406L