Development of Lead-Free Piezoelectric Thick Films with a/b-Axis-Oriented Bi4-xPrxTi3O12
Pr-substituted Bi4Ti3O12 (BPT, Bi4-xPrxTi3O12, x=0.1-0.4) polycrystalline thick films with a-/b-axes orientations and thickness of 2-3 μm were grown on sputter-grown IrO2 layers by chemical solution deposition method for developing lead-free piezoelectric film microdevices. Electric-field-induced strains measurements were performed by double-beam laser displacement meter and longitudinal strain of e=0.25 % under 400 kV/cm and piezoelectric coefficient d33=63 pm/V at 10 Hz were observed in BPT thick film of x=0.1 with a-/b-axes mixed orientations. The value of strain closely related to spontaneous polarization and monotonously decreased with increasing x. Microstructures of 3 μm-thick BPT films were fabricated by photolithography and dry etching processes with several tens micrometers in size.
Masaru Miyayama, Tadashi Takenaka, Masasuke Takata and Kazuo Shinozaki
H. Matsuda and T. Iijima, "Development of Lead-Free Piezoelectric Thick Films with a/b-Axis-Oriented Bi4-xPrxTi3O12", Key Engineering Materials, Vol. 301, pp. 61-64, 2006