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We prepared pure BiFeO3(BFO) and co-doped (Bi0.9Nd0.1)(Fe0.975V0.025)O3+δ(BNFVO) thin films on Pt(111)/Ti/SiO2/Si(100) substrates by using a chemical solution deposition method. Improved electrical properties were observed in the co-doped BNFVO thin film. The leakage current density of the co-doped BNFVO thin film was four orders of magnitude lower than that of the pure BFO, 2.6 × 10−7A/cm2at 100 kV/cm. The remnant polarization (2Pr) and the coercive electric field (2Ec) of the co-doped BNFVO thin film were 56 μC/cm2and 1393 kV/cm at an applied electric field of 1110 kV/cm and at a frequency of 1 kHz, and the values decreased with increasing measurement frequency to 18 μC/cm2and 1282 kV/cm at 10 kHz, respectively. We also confirmed that the remnant polarization (2Pr) and the coercive electric field (2Ec) were fairly saturated above a measurement frequency of 20 kHz for the BNFVO thin film. [ABSTRACT FROM AUTHOR]

Ferroelectric K0.5Bi4.5Ti4O15 (KBTi) and Cr-doped K0.5Bi4.5Ti4O15 ((K0.5Bi4.5Ti3.97 Cr0.03O15-δ), (KBTC)) thin films were prepared on Pt(111)/Ti/SiO2/Si substrates by using a chemical solution deposition method. The thin films were annealed at 750°C for 3 min by a rapid thermal annealing process under oxygen atmosphere. Compared to pure KBTi thin film, there was no structural change while improved ferroelectric and leakage current properties were observed. The values of remnant polarization (2Pr ) and coercive field (2Ec ) were 50.9 μC/cm2 and 244 kV/cm at an applied electric field of 300 kV/cm, respectively. The 2Pr we observed is compatible with that of doped bismuth layer-structured ferroelectric thin films. Leakage current density was 6.00 × 10−7 A/cm2 at 200 kV/cm. The enhanced properties of KBTC could be explained by a defect dipole (Cr′Ti-V) and increased average grain size. [ABSTRACT FROM AUTHOR]

Ferroelectric CaBi4Ti4O15 (CBTi) thin films with random orientation and high c-axis orientation were prepared on a Pt(111)/Ti/SiO2/Si(100) substrate by a chemical solution deposition method. We observed a strong dependence of ferroelectric and dielectric properties on the film orientation. The CBTi thin film with random orientation exhibited remnant polarization (2Pr) of 54 μ C/cm2 at an applied electric field of 250 kV/cm and dielectric constant (ε) of 412 at a frequency of 1 kHz. The values of 2Pr and ε were larger than those observed in the CBTi thin film with high c-axis orientation. In addition, the randomly oriented thin film showed lower leakage current density than the highly c-axis-oriented thin film. [ABSTRACT FROM AUTHOR]

SrBi5FeTi4O18 (SBFT) thin films were prepared on a Pt(111)/Ti/SiO2/Si(100) substrate using a chemical solution deposition method and annealed at 650°C under oxygen atmosphere. It was found that the polycrystalline SBFT thin film exhibits good ferroelectric properties. The values of remnant polarization (2Pr) and coercive electric field (2Ec) were 33 μ C/cm2 and 150 kV/cm at an applied electric field of 250 kV/cm, respectively. Leakage current density of the thin film was 106 A/cm2 at 100 kV/cm. The values of dielectric constant and dielectric loss were 470 and 0.05 at 1 kHz, respectively. No significant polarization fatigue was observed up to 1.44 × 1010 switching cycles. Also weak ferromagnetic properties were observed. [ABSTRACT FROM AUTHOR]

A simplified two-dimensional Monte Carlo simulation is performed to estimate the charging potential fluctuations caused by strong binary Coulomb interactions between discrete charged particles in nanometer scale trenches. It is found that the discrete charge effect can be an important part of the nanoscale trench research, inducing scattering of ion trajectories in a nanoscale trench by a fluctuating electric field. The effect can enhance the ion deposition on the side walls and disperse the material contact energy of the incident ions, among others. [ABSTRACT FROM AUTHOR]

The analytic solution for the time stationary non-monotonic double layers in multi-species plasma is presented. This solution is the analytic extension of the monotonic double layer and the solitary hole. We have derived the modified Korteweg–de Vries equation in plasmas, taking account of negative ion effects. The effects of negative ion and density on the properties of the non-monotonic double layer are discussed. [ABSTRACT FROM PUBLISHER]

5 mol % La3 +, Nd3 + or Y3 +-cosubstituted BiFe0.97Cr0.03O3 thin films (denoted by BLaFCr, BNdFCr, and BYFCr, respectively) have been successfully deposited on Pt (200)/TiO2/SiO2/Si substrates by a chemical solution deposition method. Well-saturated ferroelectric hysteresis loops and low leakage current densities have been observed in BLaFCr, BNdFCr, and BYFCr thin films with single-phase structure. The values of remanent polarization (Pr) and coercive field (Ec) were 64 μ C/cm2 and 275 kV/cm, 61 μC/cm2 and 290 kV/cm, and 31 μ C/cm2 and 315 kV/cm for BLaFCr, BNdFCr and BYFCr thin films at the maximum electric field of 712 kV/cm, respectively. In the present study, the differences in values of Pr seem to be related to the doped ionic radii. [ABSTRACT FROM AUTHOR]

Cu-doped Ba0.7Sr0.3TiO3 (BST) thin films were prepared on Pt(111)/Ti/SiO2/Si(100) substrates by a sol-gel spin coating process. The coated thin films were annealed at 750°C for 3 min in oxygen, air and nitrogen atmospheres by a rapid thermal annealing process. All of the Cu-doped BST thin films were consisted of a single phase perovskite structure and exhibited smooth crack-free surfaces. We investigated the effects of the annealing atmosphere on the microstructure and the electrical properties of the Cu-doped BST films. The Cu-doped BST film by annealing in oxygen exhibits a dielectric constant of 923 with electric field dependent tunability of 48.6% at electric field 250 kV/cm and a leakage current density of 1.82 × 10- 5A/cm2 at electric field of 150 kV/cm. [ABSTRACT FROM AUTHOR]

Neodymium-substituted Bi4Ti3O12 (BNdT) thin films were prepared by a chemical solution deposition technique on platinum- coated silicon substrates. All of the samples were annealed at the relatively low temperature of 600 °C by a rapid thermal annealing process in different atmospheres, such as O2, air, and nitrogen, and vacuum. Irrespective of different annealing atmospheres, all of the BNdT thin films exhibit good ferroelectric properties, such as a saturated hysteresis loop, good fatigue endurance, and low leakage current density. A large remanent polarization (Pr) of ∼48 μC/cm2 with an electric field of 240 kV/cm was observed from the BNdT thin film annealed in O2 atmosphere. The BNdT thin films annealed in nitrogen and vacuum, at reduced oxygen partial pressures, exhibit smaller Pr than that annealed in oxygen. The difference of Pr of the BNdT thin films annealed in different atmospheres may originate from differences in the grain sizes and the number of oxygen vacancies. [ABSTRACT FROM AUTHOR]

A study on the dependence of electron energy distribution function (EEDF) on discharge gap size in capacitive rf discharges was conducted. The evolution of the EEDF over a gap size range from 2.5 to 7 cm in 65 mTorr Ar discharges was investigated both experimentally and theoretically. The measured EEDFs exhibited typical bi-Maxwellian forms with low energy electron groups. A significant depletion in the low energy portion of the bi-Maxwellian was found with decreasing gap size. The results show that electron heating by bulk electric fields, which is the main heating process of the low-energy electrons, is greatly enhanced as the gap size decreases, resulting in the abrupt change of the EEDF. The calculated EEDFs based on nonlocal kinetic theory are in good agreement with the experiments. [ABSTRACT FROM AUTHOR]