Electrical properties of calcium doped BiFeO3 films on LaNiO3 coated Pt substrates

• Published in: Processing and Application of Ceramics Vol. 12; no. 2; pp. 153 - 163
• Main Authors: Goncalves, Lucas, Rocha, Leandro, Hangai, Bruno, Ortega, Pedro, Longo, Elson, Simões, Alexandre
• Format: Journal Article
• Language: English
• Published: University of Novi Sad 01.01.2018
• Subjects: bismuth ferrite; lanthanum nickelate; multiferroics; thin films
• ISSN: 1820-6131; 2406-1034
• DOI: 10.2298/PAC1802153G

Pure and calcium-modified (CaxBi1-xFeO3, x = 0.0, 0.1, 0.2, 0.30) thin films were fabricated on Pt(111)/Ti/SiO2/Si substrates by the soft chemical method using LaNiO3 as the bottom electrode. Highly (200)- oriented BFO film was coherently grown on LNO at 500?C. Ca-doped BiFeO3 films have a dense microstructure and rounded grains. The conventional problem of the leakage current for the highest doped film was reduced from 10-5 to 10-10 with remarkable improvement in the film/electrode interface, chemical homogeneity, crystallinity, and morphology of the BFO film. Enhanced ferroelectricity was observed at room temperature due to the bottom electrode. Fatigue-free films were grown on LaNiO3 bottom electrodes with no degradation after 1?1010 switching cycles at an applied voltage of 5 V with a frequency of 1MHz. After several tests the capacitors retained 77% of its polarization upon a retention time of 104 s. Room temperature magnetic coercive field measurements indicate that the magnetic behaviour is influenced by the nature of the bottom electrode. nema