Sr 0.8 Bi 2.5 Ta 1.2 Nb 0.9 O 9+x ferroelectric thin films prepared by two-target off-axis radio frequency magnetron sputtering

Abstract

Ferroelectric Sr0.8Bi2.5Ta1.2Nb0.9O9+x thin films on a Pt/SiO2/Si substrate were prepared by using two-target off-axis radio frequency magnetron sputtering, and their structural and electrical properties were investigated. The films crystallized with high (115) diffraction intensity at a substrate temperature of 600 °C, and showed columnar microstructure. The 600 °C sputtered films with a thickness of 440 nm exhibited remanent polarization (2Pr) of 52 μC/cm2 and coercive field (2Ec) 28 kV/cm at an applied voltage of 1.5 V. The leakage current density was about 6×10−6 A/cm2 at an electric field of 50 kV/cm. The films demonstrated fatigue free characteristics up to 1.0×1010 switching cycles under a 3 V bipolar 1 MHz square wave.

Effects of a Bi4Ti3O12 buffer layer on SrBi2Ta2O9 thin films prepared by the metalorganic decomposition

“…5 Furthermore, the value of 2 P r for the film annealed at 750°C is much higher than those reported by other groups. 1,2,8 This should be due to the high ͑200͒/͑115͒ ratio and large grain size of the film. It has been reported that the remanent polarization of SBT thin films is strongly dependent on the grain size and the relative intensity of ͑200͒ peak.…”

Structure control and characterization of SrBi2Ta2O9 thin films by a modified annealing method

“…Various techniques, including the pulse laser ablation, 1,2 metalorganic vapor deposition, 3 sol-gel, 4 radio frequency ͑rf͒ sputtering, 5 and metalorganic decomposition ͑MOD͒, 6,7 have been used to successfully fabricate SBT thin films. Among these methods, MOD is one of the most promising techniques because of its precise control of composition, large area deposition, simple equipment, and simple process.…”

Influence of substitution on dielectric diffuseness in Ba(1-x)Bi(2+2x/3)Nb2O9 ceramics prepared by chemical precursor decomposition method

“…Recently the same group has substituted Ba 2+ by La 3+ in BaBi 2 Nb 2 O 9 ceramics and found an increased diffuseness in its dielectric behavior [19]. Partial substitution of strontium ions by small size bismuth ions would increase the Curie temperature and improve the dielectric properties in both strontium bismuth tantalate, SrBi 2 Ta 2 O 9 (SBT) [20][21][22][23] and SBN [7,24,25] within the perovskitelike units. Park et al have shown that the ferroelectric transition temperature (T C ) decreased with Ba 2+ and Pb 2+ ions but increased with Ca 2+ ion which substitutes the 12-coordinated Sr 2+ site, while with trivalent Bi 3+ and La 3+ ions, T C increased with Bi 3+ ion but much decreased with La 3+ ion [26].…”