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

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).

2006 ◽  
Vol 933 ◽  
Author(s):  
Sushil Kumar Singh ◽  
Hiroshi Ishiwara

AbstractMn-substituted BiFeO3 (BFO) thin films were formed by chemical solutions deposition on Pt/Ti/SiO2/Si(100) structures. Effects of the Mn-substitution on the structure and ferroelectricity of BFO films were examined. We found that the lattice structure of the film is sensitive to the Mn-substitution and the secondary phase is appears in 50% Mn-substituted BFO films. The leakage current were increased with the Mn-substitution. However, the 5% Mn-substituted BFO film shows low leakage current than undoped BFO films in a high electric field than 0.5 MV/cm. Due to the low leakage current in Mn-doped 3, 5 and 7% BFO films, the saturated P-E hysteresis loops with remanent polarization around 100 μC/cm2 were obtained at RT.


2004 ◽  
Vol 449-452 ◽  
pp. 477-480
Author(s):  
J.H. Choi ◽  
Tae Sung Oh

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.


1999 ◽  
Vol 14 (11) ◽  
pp. 4395-4401 ◽  
Author(s):  
Seung-Hyun Kim ◽  
D. J. Kim ◽  
K. M. Lee ◽  
M. Park ◽  
A. I. Kingon ◽  
...  

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.


2001 ◽  
Vol 688 ◽  
Author(s):  
J. Rodríguez Contreras ◽  
J. Schubert ◽  
U. Poppe ◽  
O. Trithaveesak ◽  
K. Szot ◽  
...  

AbstractWe have prepared single crystalline epitaxial PbZr0.52Ti0.48O3 (PZT) and BaTiO3 (BTO) thin films on single crystalline epitaxial SrRuO3 (SRO) thin films grown on SrTiO3 (100) (STO) substrates. PZT and SRO thin films were grown using high-pressure on-axis sputtering and BTO using pulsed laser deposition (PLD). The film thickness ranged between 12 to 165 nm. Their excellent structural properties, surface smoothness and interface sharpness were demonstrated by X-Ray Diffraction measurements (XRD), High Resolution Transmission Electron Microscopy (HRTEM) and Atomic Force Microscopy (AFM). Rutherford Backscattering Spectrometry and Channeling measurements (RBS/C) were used to analyze stoichiometry and crystalline quality. Ferroelectric hysteresis loops were obtained for all films of a thickness down to 12 nm showing a decrease in the remanent polarization Pr and an increase in the coercive field Ec towards thinner film thicknesses. Furthermore we have prepared tunneling junctions with a PZT or BTO barrier thickness of 3-6 nm. Reproducible bi-stable I-V-curves and bias dependence of the conductance were obtained suggesting an influence of the ferroelectric properties of the barrier material on the tunnel current.


2012 ◽  
Vol 557-559 ◽  
pp. 1933-1936
Author(s):  
Ning Yan ◽  
Sheng Hong Yang ◽  
Yue Li Zhang

Pure BiFeO3(BFO) and Bi0.9Nd0.1Fe0.925Mn0.075O3(BNFM) thin films were deposited on Pt(111)/Ti/SiO2/Si substrate by sol-gel method. X-ray diffraction analysis showed that all the films were single perovskite structure and a phase transition appeared in Nd–Mn codoped BiFeO3 thin films. Electrical measurements indicated that the ferroelectric properties of BFO thin films were significantly improved by Nd and Mn codoping. BNFM films exhibit a low leakage current and a good P-E hysteresis loop. The remanent polarization (Pr) value of 74μC/cm2has been obtained in BNFM films, while the coercive field (Ec) is 184kV/cm.


2007 ◽  
Vol 14 (02) ◽  
pp. 229-234
Author(s):  
SARAWUT THOUNTOM ◽  
MANOCH NAKSATA ◽  
KENNETH MACKENZIE ◽  
TAWEE TUNKASIRI

Lead zirconate titanate (PZT) films with compositions near the morphotropic phase boundary were fabricated on Pt (111)/ Ti / SiO 2/ Si (100) using the triol sol–gel method. The effect of the pre-heating temperature on the phase transformations, microstructures, electrical properties, and ferroelectric properties of the PZT thin films was investigated. Randomly oriented PZT thin films pre-heated at 400°C for 10 min and annealed at 600°C for 30 min showed well-defined ferroelectric hysteresis loops with a remnant polarization of 26.57 μC/cm2 and a coercive field of 115.42 kV/cm. The dielectric constant and dielectric loss of the PZT films were 621 and 0.0395, respectively. The microstructures of the thin films are dense, crack-free, and homogeneous with fine grains about 15–20 nm in size.


2010 ◽  
Vol 177 ◽  
pp. 197-200
Author(s):  
X.A. Mei ◽  
Min Chen ◽  
K.L. Su ◽  
A.H. Cai ◽  
J. Liu ◽  
...  

Eu2O3-doped bismuth titanate (Bi1-xEuxTi3O12: BET) thin films with random oriention were fabricated on Pt/Ti/SiO2/Si substrates by rf magnetron sputtering technique, and the structures and ferroelectric properties of the films were investigated. XRD studies indicated that all of BET films consisted of single phase of a bismuth-layered structure with well-developed rod-like grains. For samples with x=0.0 , 0.25, 1.0 and 1.25, I-E characteristics exhibited negative differential resistance behaviors and their ferroelectric hysteresis loops were characterized by large leakage current, whereas for samples with x=0.5 and 0.75, I-E characteristics were simple ohmic behaviors and their ferroelectric hysteresis loops were the saturated and undistorted hysteresis loops. The remanent polarization (Pr) and coercive field (Ec) of the BET Film with x=0.75 were above 30μC/cm2 and 85KV/cm , respectively.


2010 ◽  
Vol 434-435 ◽  
pp. 281-284
Author(s):  
Min Chen ◽  
A.H. Cai ◽  
X.A. Mei ◽  
K.L. Su ◽  
Chong Qing Huang ◽  
...  

Pr6O11-doped bismuth titanate (BixPryTi3O12: BPT) thin films with random oriention were fabricated on Pt/Ti/SiO2/Si substrates by rf magnetron sputtering technique, and the structures and ferroelectric properties of the films were investigated. XRD studies indicated that all of BPT films consisted of single phase of a bismuth-layered structure with well-developed rod-like grains. For samples with y=0.06, 0.3, 1.2 and 1.5, ferroelectric hysteresis loops were characterized by large leakage current, whereas for samples with y=0.6 and 0.9, ferroelectric hysteresis loops were the saturated and undistorted hysteresis loops. The remanent polarization ( Pr ) and coercive field (Ec) of the BPT Film with y=0.9 were above 35μC/cm2 and 80KV/cm , respectively. After 3×1010 switching cycles, 20% degradation of 2Pr is observed in the film with y=0.9.


2006 ◽  
Vol 301 ◽  
pp. 57-60 ◽  
Author(s):  
Masahiro Kurachi ◽  
Hirofumi Matsuda ◽  
Takashi Iijima ◽  
Hiroshi Uchida ◽  
Seiichiro Koda

Nd-substituted Bi4Ti3O12 (BNT) polycrystalline thin films with preferred a-/b-axes orientations were grown on sputter-grown IrO2(101) layers by chemical solution deposition method. After optimizing the heat treatment conditions, insulating characters and ferroelectric properties in 250-nm-thick BNT thin films with a-/b-axes orientations were investigated at room temperature. Low leakage current density of J=10-7~10-8 A/cm2 at 100 kV/cm and fair value of remnant polarization (2Pr=31 μC/cm2 at 400 kV/cm) were measured even though the Bi2O2 blocking layer aligned parallel to the film normal.


Coatings ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 502
Author(s):  
Zhi-Yong Wu ◽  
Cai-Bin Ma

Bismuth ferrite (BiFeO3) has proven to be promising for a wide variety of microelectric and magnetoelectric devices applications. In this work, a dense (Ba0.65Sr0.35)TiO3(BST)/(Bi0.875Nd0.125)FeO3(BNF)/BST trilayered thin film grown on Pt-coated Si (100) substrates was developed by the rf-sputtering. For comparison, single-layered BNF and BST were also prepared on the same substrates, respectively. The results show that the dielectric loses suppression in BST/BNF/BST trilayered thin films at room temperature but has enhanced ferromagnetic and ferroelectric properties. The remnant polarization (Pr) and coercive electronic field (Ec) were 5.51 μC/cm2 and 18.3 kV/cm, and the remnant magnetization (Mr) and coercive magnetic field (Hc) were 10.1 emu/cm3 and 351 Oe, respectively, for the trilayered film. We considered that the bismuth’s volatilization was limited by BST bottom layers making the Bi/Fe in good station, and the action of BST layer in the charge transfer between BNF thin film and electrode led to the quite low leakage current and enhanced multiferroic property. The origin of the mechanism of the highly enhanced dielectric constant and decreased loss tanδ was discussed.


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