The effect of excess bismuth on the ferroelectric properties of SrBi2Ta2O9 thin films

1997 ◽  
Vol 12 (6) ◽  
pp. 1569-1575 ◽  
Author(s):  
Tze-Chiun Chen ◽  
Tingkai Li ◽  
Xubai Zhang ◽  
Seshu B. Desu
Keyword(s):  
Thin Films ◽  
Solid Solution ◽  
Grain Size ◽  
Leakage Current ◽  
Ferroelectric Properties ◽  
Substantial Improvement ◽  
Second Phase ◽  
Limited Solid Solution ◽  
Low Leakage ◽  
Ferroelectric Hysteresis

The effect of excess bismuth on the ferroelectric properties of SrBi2Ta2O9 (SBT) thin films having a perovskite-like layered structure was investigated for excess bismuth contents ranging from 0% to 100%. For the first time, a limited solid solution of SBT and Bi2O3 was shown to exist when the amount of excess Bi was less than 50%. The formation of a solid solution enhanced the grain size and a-b plane orientation of the films, resulting in substantial improvement in the ferroelectric hysteresis properties of the films. On the other hand, when the amount of excess Bi exceeded 50%, Bi2O3 appeared as a second phase which led to high leakage current and poor ferroelectric hysteresis curves. 30–50% excess Bi content was found to be the optimum composition with respect to grain size, crystallographic orientation, and single phase formation. Within this range, SBT films exhibit low leakage current density (˜10−9 A/cm2) and maximum remanent polarization (2Pr ˜12 µC/cm2).

Low leakage current and good ferroelectric properties of SrBi2(Ta0.7Nb0.3)2O9–Bi3TiTaO9 solid solution thin film

2001 ◽  
Vol 79 (13) ◽  
pp. 2067-2069 ◽  
Author(s):  
Masatoshi Mitsuya ◽  
Norimasa Nukaga ◽  
Takayuki Watanabe ◽  
Hiroshi Funakubo ◽  
Keisuke Saito ◽  
...  
Keyword(s):  
Thin Film ◽  
Solid Solution ◽  
Leakage Current ◽  
Ferroelectric Properties ◽  
Low Leakage ◽  
Low Leakage Current

Ferroelectric Characteristics of SrxBi2.4Ta2O9 Thin Films and Electrical Properties of the Pt/SrxBi2.4Ta2O9/TiO2/Si Structure

2004 ◽  
Vol 449-452 ◽  
pp. 477-480
Author(s):  
J.H. Choi ◽  
Tae Sung Oh
Keyword(s):  
Thin Films ◽  
Electrical Properties ◽  
Coercive Field ◽  
Remanent Polarization ◽  
Ferroelectric Properties ◽  
Memory Window ◽  
Low Leakage ◽  
Low Leakage Current ◽  
Metalorganic Decomposition ◽  
Ferroelectric Hysteresis

Ferroelectric characteristics of the 400 nm-thick SrxBi2.4Ta2O9(0.7≤x≤1.3) thin films processed by metalorganic decomposition were investigated, and electrical properties of the Pt/Sr0.85Bi2.4Ta2O9/TiO2/Si structure prepared using TiO2 buffer layer were characterized. The Sr-deficient SrxBi2.4Ta2O9 films exhibited well-developed ferroelectric hysteresis curves compared to those of the Sr-excess films. The Sr0.85Bi2.4Ta2O9 film exhibited optimum ferroelectric properties, such as high remanent polarization and low leakage current density, among SrxBi2.4Ta2O9 films. A memory window of the Pt/SrxBi2.4Ta2O9/TiO2/Si structure was dependent upon the coercive field of the SrxBi2.4Ta2O9 film, and the Pt/SrxBi2.4Ta2O9/TiO2/Si exhibited a maximum memory window of 1.3 V at the sweeping voltage of ±5 V.

scholarly journals Simple and Rapid Fabrication of Na0.5K0.5NbO3 Thin Films by a Chelate Route

2013 ◽  
Vol 2013 ◽  
pp. 1-7
Author(s):  
A. Fernández Solarte ◽  
N. Pellegri ◽  
O. de Sanctis ◽  
M. G. Stachiotti
Keyword(s):  
Thin Films ◽  
Ferroelectric Properties ◽  
Hysteresis Loops ◽  
Chelating Agent ◽  
Secondary Phase ◽  
Secondary Phases ◽  
Solution Synthesis ◽  
Low Leakage ◽  
Low Leakage Current ◽  
Ferroelectric Hysteresis

Na0.5K0.5NbO3 (NKN) thin films were prepared by a chelate route which offers the advantage of a simple and rapid solution synthesis. The route is based on the use of acetoin as a chelating agent. The process was optimized by investigating the effects of alkaline volatilization on film properties. While we observed no evidence of stoichiometry problems due to potassium volatilization loss during the heat treatments, thin films synthesized with insufficient sodium excess presented a potassium-rich secondary phase, which has a significant influence on the ferroelectric properties. We show that the amount of spurious phase decreases with increasing Na+ concentration, in such a way that a 20 mol% Na+ excess is necessary to fully compensate the volatilization loss that occurred during the heat treatment. In this way, NKN thin films annealed at 650°C presented a well-crystallized perovskite structure, no secondary phases, well-defined ferroelectric hysteresis loops (Pr~9 μC/cm2, EC~45 kV/cm), and low leakage current density (2×10-7 A/cm2 at 80 kV/cm).

Microstructure and ferroelectric properties of fine-grained BaxSr1−xTiO3 thin films prepared by metalorganic decomposition

1996 ◽  
Vol 11 (10) ◽  
pp. 2588-2593 ◽  
Author(s):  
Majed S. Mohammed ◽  
Ratna Naik ◽  
Joseph V. Mantese ◽  
Norman W. Schubring ◽  
Adolph L. Micheli ◽  
...  
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Relative Permittivity ◽  
Ferroelectric Properties ◽  
Hysteresis Loops ◽  
Measurement Temperature ◽  
Fine Grained ◽  
Metalorganic Decomposition ◽  
Ferroelectric Hysteresis

Thin films of BaxSr1−xTiO3 (x = 0.7, 0.8, 0.9, and 1.0) were prepared by metalorganic decomposition (MOD). The relative permittivity, dissipation, polarization, resistivity, and grain size of these films were studied as a function of composition and temperature. Ferroelectric hysteresis loops were observed for all values of x and were found to be independent of measurement temperature though strongly dependent upon grain size.

Large Remanent Polarization and Low Leakage Current in High-Tc 0.2Bi (Ni1/2Ti1/2)O3-0.8PbTiO3 Ferroelectric Thin Films

2014 ◽  
Vol 602-603 ◽  
pp. 804-807
Author(s):  
Zhen Kun Xie ◽  
Zhen Xing Yue
Keyword(s):  
Thin Films ◽  
Curie Temperature ◽  
Leakage Current ◽  
Ferroelectric Properties ◽  
High Curie Temperature ◽  
Si Substrates ◽  
Low Leakage ◽  
Low Leakage Current ◽  
Average Grain Size ◽  
Measured Polarization

High Curie-temperature (Tc) polycrystalline 0.2Bi (Ni1/2Ti1/2)O3-0.8PbTiO3 (0.2BNT-0.8PT) thin films were fabricated on Pt (111)/Ti/SiO2/Si substrates via an aqueous chemical solution deposition (CSD) technique. The thin films exhibited good crystalline quality and dense, uniform microstructures with an average grain size of 55 nm. The dielectric, piezoelectric and ferroelectric properties of the films was investigated. The permittivity peak appeared at 485 °C, which was 100 °C higher than that of Pb (Zr,Ti)O3 thin films. The local effective piezoelectric coefficient d33 was 45 pm/V at 3V. Moreover, a large remnant polarization with 2Pr up to 92 uC/cm2 and a small leakage current of 2.2×10-5 A/cm2 under an electric field of 400 kV/cm were obtained. The magnitude of the measured polarization and the high Curie temperature make the 0.2BNT-0.8PT films promising candidates for application in high-temperature ferroelectric and piezoelectric devices.

An optimized process for fabrication of SrBi2Ta2O9 thin films using a novel chemical solution deposition technique

1999 ◽  
Vol 14 (11) ◽  
pp. 4395-4401 ◽  
Author(s):  
Seung-Hyun Kim ◽  
D. J. Kim ◽  
K. M. Lee ◽  
M. Park ◽  
A. I. Kingon ◽  
...  
Keyword(s):  
Thin Films ◽  
Chemical Solution Deposition ◽  
Low Voltage ◽  
Ferroelectric Properties ◽  
Chemical Solution ◽  
Solution Deposition ◽  
Chemical Solution Deposition Method ◽  
Low Leakage ◽  
Low Leakage Current ◽  
Voltage Saturation

Ferroelectric SrBi2Ta2O9 (SBT) thin films on Pt/ZrO2/SiO2/Si were successfully prepared by using an alkanolamine-modified chemical solution deposition method. It was observed that alkanolamine provided stability to the SBT solution by retarding the hydrolysis and condensation rates. The crystallinity and the microstructure of the SBT thin films improved with increasing annealing temperature and were strongly correlated with the ferroelectric properties of the SBT thin films. The films annealed at 800 °C exhibited low leakage current density, low voltage saturation, high remanent polarization, and good fatigue characteristics at least up to 1010 switching cycles, indicating favorable behavior for memory applications.

scholarly journals Effect of Rare Earth Ce on Deep Stamping Properties of High-Strength Interstitial-Free Steel Containing Phosphorus

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1473
Author(s):  
Hao Wang ◽  
Yanping Bao ◽  
Chengyi Duan ◽  
Lu Lu ◽  
Yan Liu ◽  
...  
Keyword(s):  
Solid Solution ◽  
Grain Size ◽  
Rare Earth ◽  
High Strength ◽  
Rolling Process ◽  
P Element ◽  
Second Phase ◽  
Strengthening Effect ◽  
Interstitial Free ◽  
If Steel

The influence of rare earth Ce on the deep stamping property of high-strength interstitial-free (IF) steel containing phosphorus was analyzed. After adding 120 kg ferrocerium alloy (Ce content is 10%) in the steel, the inclusion statistics and the two-dimensional morphology of the samples in the direction of 1/4 thickness of slab and each rolling process were observed and compared by scanning electron microscope (SEM). After the samples in each rolling process were treated by acid leaching, the three-dimensional morphology and components of the second phase precipitates were observed by SEM and energy dispersive spectrometer (EDS). The microstructure of the sample was observed by optical microscope, and the grain size was compared. Meanwhile, the content and strength of the favorable texture were analyzed by X-ray diffraction (XRD). Finally, the mechanical properties of the product were analyzed. The results showed that: (1) The combination of rare earth Ce with activity O and S in steel had lower Gibbs free energy, and it was easy to generate CeAlO3, Ce2O2S, and Ce2O3. The inclusions size was obviously reduced, but the number of inclusions was increased after adding rare earth. The morphology of inclusions changed from chain and strip to spherical. The size of rare earth inclusions was mostly about 2–5 μm, distributed and dispersed, and their elastic modulus was close to that of steel matrix, which was conducive to improving the structure continuity of steel. (2) The rare earth compound had a high melting point. As a heterogeneous nucleation point, the nucleation rate was increased and the solidification structure was refined. The grade of grain size of products was increased by 1.5 grades, which is helpful to improve the strength and plasticity of metal. (3) Rare earth Ce can inhibit the segregation of P element at the grain boundary and the precipitation of Fe(Nb+Ti)P phase. It can effectively increase the solid solution amount of P element in steel, improve the solid solution strengthening effect of P element in high-strength IF steel, and obtain a large proportion of {111} favorable texture, which is conducive to improving the stamping formability index r90 value.

The Effect of RuO2/Pt Hybrid Bottom Electrode Structure on The Microstructure and Ferroelectric Properties of Sol-Gel Derived PZT Thin Films

1997 ◽  
Vol 493 ◽  
Author(s):  
Seung-Hyun Kim ◽  
J. G. Hong ◽  
J. C. Gunter ◽  
H. Y. Lee ◽  
S. K. Streiffer ◽  
...  
Keyword(s):  
Thin Films ◽  
Leakage Current ◽  
Bottom Electrode ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
Chemical Solution ◽  
Electrode Structure ◽  
Solution Deposition ◽  
Pzt Thin Films ◽  
Chemical Solution Deposition Method

ABSTRACTFerroelectric PZT thin films on thin RuO2 (10, 30, 50nm)/Pt hybrid bottom electrodes were successfully prepared by using a modified chemical solution deposition method. It was observed that the use of a lOnm RuO2Pt bottom electrode reduced leakage current, and gave more reliable capacitors with good microstructure compare to the use of thicker RuO2/Pt bottom electrodes. Typical P-E hysteresis behavior was observed even at an applied voltage of 3V, demonstrating greatly improved remanence and coercivity. Fatigue and breakdown characteristics, measured at 5V, showed stable behavior, and only below 13-15% degradation was observed up to 1010 cycles. Thicker RuO2 layers resulted in high leakage current density due to conducting lead ruthenate or PZT pyrochlore-ruthenate and a rosette-type microstructure.

Ferroelectric properties and leakage current characteristics of radio-frequency-sputtered SrBi2(V0.1Nb0.9)2O9 thin films

2004 ◽  
Vol 96 (4) ◽  
pp. 2181-2185 ◽  
Author(s):  
S. Ezhilvalavan ◽  
Victor Samper ◽  
Toh Wei Seng ◽  
Xue Junmin ◽  
John Wang
Keyword(s):  
Thin Films ◽  
Radio Frequency ◽  
Leakage Current ◽  
Ferroelectric Properties ◽  
Current Characteristics

Homogeneous Al-Ti and Al-Ti-Si Thin Alloy Films

1985 ◽  
Vol 54 ◽  
Author(s):  
Albertus G. Dirks ◽  
Tien Tien ◽  
Janet M. Towner
Keyword(s):  
Thin Films ◽  
Heat Treatment ◽  
Grain Size ◽  
Electrical Resistivity ◽  
Phase Formation ◽  
Alloy Composition ◽  
Al Alloy ◽  
Second Phase ◽  
Alloy Films ◽  
Microstructure And Properties

ABSTRACTThe microstructure and properties of thin films depends strongly upon the alloy composition. A study was made of the metallurgical aspects of homogeneous Al alloy films, particularly the binary Al-Ti and the ternary Al-Ti-Si systems. Electrical resistivity, grain size morphology, second phase formation and electromigration have been studied as a function of the alloy composition and its heat treatment.

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