Characterization of columnar BiFeO₃ thick films prepared by magnetic field-assisted pulsed laser deposition

Abstract

Polycrystalline BiFeO3 thick films were prepared on Pt/TiO2/SiO2/Si substates by using magnetic field-assisted pulsed laser deposition. Columnar BiFeO3 thick films were successfully obtained with a thickness of 1.8 μm, owing to an oblique incoming flux and high deposition rate by the confinement of the plume under a magnetic field. In the columnar BiFeO3 thick films, a saturated P-E hysteresis loop was obtained at RT, and the remanent polarization (P r ) and coercive field (E c ) were 42 μC cm−2 and 380 kV cm−1, respectively. Also, the piezoelectric response measured by atomic force microscopy showed a butterfly-shaped curve, and the piezoelectric d 33 coefficient was about 50 pm V−1.

Characterization of polycrystalline BiFeO3 films prepared by magnetic-field-assisted 90° off-axis pulsed laser deposition

“…The information on the distribution of the magnetic field strength in a magnet has been reported previously. 26) For the configuration of a magnetic fieldassisted 90°off-axis PLD compared with that of conventional on-axis PLD as shown in Fig. 1(b), the substrate was tilted to be perpendicular to the target to avoid direct impingement of evaporated species.…”