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(Eu, Mn) co-doped bismuth ferrite [(Bi0.9Eu0.1)(Fe0.9Mn0.1)O3 (BEFMO)] thin films were deposited on Pt(111)/Ti/SiO2/Si substrates by using a chemical solution deposition method. The coated films were annealed in N2, air and O2 atmospheres at 550°C for 30 min. Effects of annealing atmosphere on the crystal structure, ferroelectric properties and leakage current density of the BEFMO thin films were investigated. The single-phase rhombohedral perovskite crystal structure of all the samples was confirmed by x-ray diffraction analysis. From the electrical studies, the BEFMO thin film annealed in air atmosphere showed better electrical properties than O2 and N2 atmosphere annealed samples. The largest remnant polarization 96.4 μC/cm2 at an electric field 1060 kV/cm was obtained from the BEFMO thin film annealed in air. [ABSTRACT FROM AUTHOR]

Thin films of BiFeO3 (BFO), Bi0.9Eu0.1Fe0.975Cu0.025O3-δ (BEuFC) and Bi0.9Dy0.1 Fe0.975Cu0.025O3-δ (BDyFC) were prepared on Pt(111)/Ti/SiO2/Si(100) substrates via a chemical solution deposition method. X-ray diffraction and Raman studies show distorted rhombohedral perovskite crystal structure for all the samples. Micro structural features and morphological changes of the BFO, BEuFC and BDyFC were examined by using a FE-SEM analysis. The leakage current density was found to be greatly reduced for the BEuFC and the BDyFC thin films. The largest remnant polarization (2Pr) 68 μC/cm2 (at 1336 kV/cm) and the lowest coercive field (2Ec) 845 kV/cm (at 931 kV/cm) were observed from the BEuFC and the BDyFC thin films, respectively. [ABSTRACT FROM AUTHOR]

The structural and electrical properties of BiFeO3 (BFO) and rare earth metal ions (Re) co-substituted (Bi0.9Re0.1)(Fe0.9Mn0.1)O3-δ (Re = Nd, Sm, Ce and Tb) thin films prepared on Pt(111)/Ti/SiO2/Si(100) substrates via a chemical solution deposition method were investigated. The significant decrease of leakage current density and improved ferroelectric properties were observed from the co-substituted thin films. The largest remnant polarization (2Pr) (61.7 μC/cm2) and the lowest coercive field (2Ec) 657 kV/cm at 931 kV/cm were measured from the (Bi0.9Ce0.1)(Fe0.9Mn0.1)O3-δ thin film. The leakage current density value of (Bi0.9Sm0.1)(Fe0.9Mn0.1)O3-δ thin film (3.29 × 10−5A/cm2) was found to be two order lower than that of the pure BFO. [ABSTRACT FROM AUTHOR]

A-site non-stoichiometric lead-free 0.93(K0.5Na0.5)(1 + x)NbO3-0.07LiNbO3 (KNNL) piezoelectric ceramics were prepared by a solid state reaction. The contents of both K and Na were simultaneously controlled to -4 mol% deficient. The K3Li2Nb5O15 second phase was observed in most of the composition except for 0 mol%. The polymorphic phase transition (PPT) between the tetragonal and orthorhombic phases was found from X-ray diffraction and temperature-dependent dielectric constant at around -2 mol%. With increasing (K+Na) ion deficiency, the PPT temperature of KNNL ceramics increased but Curie temperature (TC) decreased. The piezoelectric constant was 155 pC/N for nominally stoichiometric KNNL and decreased as decreasing (K+Na) content. [ABSTRACT FROM AUTHOR]

The effects of Bi(Zn0.5Ti0.5)O3 (BZT) substitution in BaTiO3 (BT) or (Bi0.5Na0.5)TiO3 (BNT) piezoelectric ceramics were studied. (1-x)BaTiO3-xBi(Zn0.5Ti0.5)O3 (x = 0.02, 0.04, 0.06, 0.08, 0.10, 0.20, 0.30, and 0.40) and (1-y)(Bi0.5Na0.5)TiO3-yBi(Zn0.5Ti0.5)O3 (y = 0, 0.01, 0.025, 0.05, 0.10, and 0.20) ceramics were prepared by a solid state reaction method. The structures and surface morphologies have been examined using an X-ray diffraction and scanning electron microscopy, respectively. The grain size and density increased with increasing the amount of BZT in both systems. Curie temperatures (TC) were decreased as BZT substituted. Piezoelectric properties also decreased with the substitution of BZT. [ABSTRACT FROM AUTHOR]

Ferroelectric Na0.5Bi4.5Ti4O15 (NaBTi) thin films, selectively controlled in c-axis and random orientation, were fabricated on a Pt(111)/Ti/SiO2/Si(100) substrate by using a chemical solution deposition method. The preferred orientation of the thin films annealed at 750°C under oxygen atmosphere was confirmed by X-ray diffraction and scanning electron microscope studies. We found that ferroelectric, dielectric, and leakage current properties were strongly related to the crystallographic orientation of NaBTi thin films; the randomly oriented NaBTi thin film exhibited better properties than the c-axis oriented thin film. The values of remnant polarization (2Pr), dielectric constant, and leakage current density were 21 μC/cm2 at 300 kV/cm, 630 at 100 kHz, and 7.4 × 10-6 A/cm2 at 100 kV/cm for the randomly oriented thin film, respectively, and 6 μC/cm2, 420, and 1.1 × 10-1 A/cm2 for the c-axis oriented thin film, respectively. Also, no polarization fatigue was observed in both NaBTi thin films up to 107 switching cycles. [ABSTRACT FROM AUTHOR]

The formation of phase-pure BiFeO 3 (BFO) thin films using a chemical solution deposition on platinium electrode has been investigated systematically by changing the annealing condition of the films. From the X-ray diffraction results, it was found that the formation of the phase-pure BFO was favorable under lower oxygen partial pressure, slower heating rate and Pt(200)/Ti/SiO 2 /Si(100) substrate. The remanent polarization ( P r ) and coercive field ( E c ) values of the phase-pure BFO thin film annealed at 600°C in nitrogen atmosphere by conventional furnace annealing method are approximately 0.9 μC/cm 2 and 20 kV/cm, respectively. [ABSTRACT FROM AUTHOR]

Lanthanides (La3+, Nd3+, Sm3+ and Eu3+) doped Bi4Ti3O12 (BIT) films fabricated on p-type Si(100) substrates by a sol-gel spin coating process. The films were characterized by X-ray diffractometer and scanning electron microscope. Memory windows calculated from the measured C-V hysteresis curves were approximately 3.5, 0.85, 0.8, and 0.54 V for La-, Nd-, Sm-, and Eu-doped BIT films with a sweep voltage of ± 10 V, respectively. The effects of lanthanides substitution for Bi3+ in the perovskite layer on the electrical properties, such as C-V and I-V characteristics, have been reported. [ABSTRACT FROM AUTHOR]

The dependencies of the stack number N on perpendicular exchange-biasing (Hex) and coercivity Hc) in [Pd/Co]N and [Pd/Co (or CoFe)]N/FeMn multilayers were investigated. With the help of the careful designs of layer structures, a series of samples whose surface anisotropies have the linear function N was prepared with constant bulk anisotropies. From the experimental data obtained, it was found that Hex does not depend on the surface anisotropy, while Hc shows a strong dependence. Therefore, it is possible to tailor wide ranges of Hc (300–600 Oe) without varying Hex (∼200 Oe) through the single control parameter stack number N. [ABSTRACT FROM AUTHOR]