Thickness dependence of piezoelectric properties of BiFeO sub(3) films fabricated using rf magnetron sputtering system

• Published in: Japanese Journal of Applied Physics Vol. 55; no. 10; p. 10TA16
• Main Authors: Aramaki, Masaaki, Kariya, Kento, Yoshimura, Takeshi, Murakami, Shuichi, Fujimura, Norifumi
• Format: Journal Article
• Language: English
• Published: 01.10.2016
• Subjects: Crystal defects; Density; Energy harvesting; Magnetron sputtering; Piezoelectricity; Texts; Thickness; Vibration
• ISSN: 0021-4922; 1347-4065
• DOI: 10.7567/JJAP.55.10TA16

The piezoelectric property of BiFeO sub(3) films prepared on a (100) LaNiO sub(3)/Si(100) substrate using an rf magnetron sputtering system was investigated for their applications in MEMS vibration energy harvesters. The X-ray diffraction profiles indicate that (100)-oriented BiFeO sub(3) films with thicknesses from 450 to 1750 nm were obtained at a deposition temperature of 510 [degrees]C. All the films showed well-defined ferroelectric hysteresis loops at room temperature. The thickness dependence of crystallinity and electrical properties indicated that the films have a bottom layer with a high defect density. The e sub(31,f) piezoelectric coefficient and electromechanical coupling factor (ProQuest: Formulae and/or non-USASCII text omitted) increase with increasing film thickness and reach ?3.2 C/m super(2) and 3.3%, respectively, at a thickness of 1750 nm, which is considered to be caused by the decrease in defect density.