Impact of defects on the electrical properties of BiFeO₃ thin films

Abstract

The impact of defects on the electrical properties of bismuth ferrite thin films has been studied. Secondary phases and oxygen vacancies were the main defects considered. Thin films with secondary phases show higher conductivities than single-phase films. Monophasic films annealed in oxygen atmosphere shows lower conductivity than the non-annealed film. For selected thin film with secondary phase, the relaxation in the grain boundary was predominant with activation energy $E_a=0.44$ eV, suggesting the first ionization oxygen vacancies as the relaxation mechanism in the studied films. The electric field effect on relaxation processes was similarly to Arrhenius thermally activated process.

Keywords:

• Defects
• bismuth ferrite
• thin films

Additional information

Funding

This work was supported by the Fundação de Amparo à Pesquisa do Estado de São Paulo, FAPESP (Project 2017/13769-1); the Conselho Nacional de Desenvolvimento Científico e Tecnológico, CNPq (Grant no. 304604/2015-1); and the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, CAPES (Project: CAPES-PRINT).