Effects of BaTiO₃Content and Mn Doping on Ferroelectric Properties of NaNbO₃–BaTiO₃Thin Films Prepared by Chemical Solution Deposition

Abstract

Lead-free ferroelectric NaNbO 3 -BaTiO 3 thin films were prepared by chemical solution deposition. Perovskite single-phase NaNbO 3 -BaTiO 3 thin films were successfully fabricated at 550 C on Pt/TiO x /SiO 2 /Si substrates. The ferroelectric properties of the NaNbO 3 -BaTiO 3 thin films depended on the BaTiO 3 content of NaNbO 3 -BaTiO 3 . Among NaNbO 3 -BaTiO 3 films with various BaTiO 3 concentrations, the 0.95NaNbO 3 -0.05BaTiO 3 thin films showed relatively large polarization at À190 C, although the insulating resistance of the films was not sufficiently high at room temperature. To improve the electrical resistivity at ambient temperatures, Mn doping of 0.95NaNbO 3 -0.05BaTiO 3 was examined. The leakage current density of the films was found to be greatly reduced by a small amount of Mn doping. 1.0 mol % Mn-doped 0.95NaNbO 3 -0.05BaTiO 3 thin films showed well-shaped slim ferroelectric polarization-electric field (P-E ) hysteresis loops at room temperature. The remanent polarization (P r ) and coercive field (E c ) values of the 1.0 mol % Mn-doped 0.95NaNbO 3 -0.05BaTiO 3 thin films at 1 kHz were approximately 5 mC/cm 2 and 50 kV/cm, respectively. Furthermore, the ferroelectric P-E loops of the 1.0 mol % Mn-doped 0.95NaNbO 3 -0.05BaTiO 3 thin films showed good frequency dependence and could be characterized at a frequency as low as 1 Hz. #

Improvement in Ferroelectric Properties of Chemically Synthesized Lead-Free Piezoelectric (K,Na)(Nb,Ta)O3 Thin Films by Mn Doping

“…13,15,16,23,24,[29][30][31][32] Therefore, Mn-modified KNNT20 thin films were examined to improve the ferroelectric properties at room temperature. From the XRD data in Fig.…”

“…In this process, several processing factors, such as the selection of starting materials and the adjustment of chemical composition as well as processing conditions, should be controlled to achieve the desired crystallographic phase, crystallinity, microstructure, and electrical properties of the resultant thin films. [10][11][12][13][14][15][16] In general, the major problem with alkali-niobate-based thin films is their high leakage current, which makes the evaluation of ferroelectric properties at ambient temperatures difficult. This might be attributed to the formation of oxygen vacancies accompanied by the volatilization of alkali ions during the heating process.…”

Growth and properties of highly oriented lead-free Mn-doped NaNbO3–BaTiO3 piezoelectric thin films prepared by chemical solution deposition

“…3 shows the leakage-current density of the Mn100y%NN-BT95 (y ¼0.01, 0.03) thin films as a function of the electric field. Mn doping of the NN-BT films is very effective in decreasing leakage current, especially in the high electric field range as reported for Mn-doped NN-BT95 films on Pt/TiO x /SiO 2 /Si [12,13]. Moreover, the leakage current properties depend on the doped Mn ion concentration.…”

“…Thus, improvement in ferroelectric properties is strongly required for realizing piezoelectric alkali niobate-based, such as NN-BT, thin films. The synthesis of perovskite polycrystalline NN-BT thin films on Pt/TiO x / SiO 2 /Si substrates using a metal-organic precursor solution has been reported [12,13]. From the experimental data for NN-BT polycrystalline thin films on Pt/TiO x /SiO 2 /Si substrates, among several NN-BT thin films with various BT concentrations, the 0.95NaNbO 3 -0.05BaTiO 3 thin films showed the largest ferroelectric properties, although the electrical resistivity of the films were not sufficient at room temperature.…”

Preparation and Size Control of Sodium Niobate Nanocube at Various Solvothermal Conditions

“…Sodium niobate (NaNbO3) is a perovskite oxide represented by ABO3 chemical formula. Perovskite oxides have an important role in the fabrication of many electric devices [18][19][20]. NaNbO3 -solid solutions has been widely studied as a dielectric and piezoelectric material.…”