BiFeO3 (BFO) has attracted much attention because of its room-temperature multiferroic properties with a ferroelectric Curie temperature of Tc~-830 °C and an antiferromagnetic Néel temperature of TN~370 °C. Concerning the electrical properties, although its spontaneous polarization is as large as ~100μC/cm2, the piezoelectric constant (d33~60pm/V) is far smaller than those of lead containing piezoceramics, such as Pb(Zr,Ti)O3 (PZT). An improved piezoelectric response is expected in the solid solution of rhombohedral BFO and tetragonal BiCoO3, (1-x)BiFeO3-xcBiCoO3 (BFCO), owing to the presence of morphotropic phase boundary (MPB)1) similar to PZT. In this study, epitaxial thin films of BFCO with x = 0 - 0.1 were prepared on SrRuO3(SRO) (001)/SrTiO3(STO) (001) substrates by pulsed laser deposition, and their crystal structure and electrical properties were investigated. We successfully obtained single phase of epitaxial BFCO thin films with well-saturated polarization-electric field hysteresis loops at room temperature. Sharp BFCO/SRO and SRO/STO interfaces without intermixing and a good quality of BFCO were found by transmission electron microscopy. The effective d33 estimated from the slope of the displacement-electric curve of the BFO film was ~ 60 pm/V, which is comparable to that reported by other investigators. The d33 value of the BFCO thin film increased with increasing Co content and reached ~100 pm/V at x = 0.1.
|ジャーナル||Funtai Oyobi Fummatsu Yakin/Journal of the Japan Society of Powder and Powder Metallurgy|
|出版ステータス||Published - 2014 1 1|
ASJC Scopus subject areas
- Mechanical Engineering
- Industrial and Manufacturing Engineering
- Metals and Alloys
- Materials Chemistry