Open Access Nano Express

Study on Resistance Switching Properties of Na0.5Bi0.5TiO3Thin Films Using Impedance Spectroscopy

Ting Zhang, Xinan Zhang, Linghong Ding and Weifeng Zhang*

Author Affiliations

Key Laboratory of Photovoltaic Materials of Henan Province, School of Physics and Electronics, He’nan University, 475004, Kaifeng, People’s Republic of China

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Nanoscale Research Letters 2009, 4:1309-1314  doi:10.1007/s11671-009-9397-4

Published: 25 July 2009

Abstract

The Na0.5Bi0.5TiO3(NBT) thin films sandwiched between Au electrodes and fluorine-doped tin oxide (FTO) conducting glass were deposited using a sol–gel method. Based on electrochemical workstation measurements, reproducible resistance switching characteristics and negative differential resistances were obtained at room temperature. A local impedance spectroscopy measurement of Au/NBT was performed to reveal the interface-related electrical characteristics. The DC-bias-dependent impedance spectra suggested the occurrence of charge and mass transfer at the interface of the Au/NBT/FTO device. It was proposed that the first and the second ionization of oxygen vacancies are responsible for the conduction in the low- and high-resistance states, respectively. The experimental results showed high potential for nonvolatile memory applications in NBT thin films.

Keywords:
Na0.5Bi0.5TiO3(NBT) thin films; Resistance switching; Impedance spectroscopy; Interfacial characteristics; Oxygen vacancies