Leakage behavior and conduction mechanisms of Ba(Ti0.85Sn0.15)O3/Bi1.5Zn1.0Nb1.5O7 heterostructures

Polycrystalline Ba(Ti0.85Sn0.15)O-3/Bi1.5Zn1.0Nb1.5O7 (BTS/BZN) heterostructure thin films were deposited on LaNiO3/SiO2/Si substrates by pulsed laser deposition. The leakage mechanisms of the BTS/BZN heterostructure thin films were studied in the temperature range from 303 to 403 K. At a high electric field (> 100 kV/cm) and a positive bias, the leakage is dominated by space-charge-limited-current, while Fowler-Nordheim tunneling is the main reason for conduction under a negative bias. At a low electric field, the leakage current is controlled by the Ohmic contact. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3406136]