Enhanced remnant polarization in ferroelectric Bi6Fe2Ti3O18 thin films

CrystEngComm ◽  
2015 ◽  
Vol 17 (7) ◽  
pp. 1609-1614 ◽  
Author(s):  
Dongpo Song ◽  
Xuzhong Zuo ◽  
Bing Yuan ◽  
Xianwu Tang ◽  
Wenhai Song ◽  
...  
Keyword(s):  
Thin Films ◽  
Remnant Polarization ◽  
Ferroelectric Materials ◽  
Practical Applications ◽  
Ferroelectric Memory ◽  
Large Remnant Polarization

For practical applications of ferroelectric memory, a large remnant polarization in nontoxic Pb-free ferroelectric materials is required.

Fabrication and Electrical Properties of P(VDF-TrFE)/Bi3.5Nd0.5Ti3O12 Bi-Layer Composite Ferroelectric Thin Films

2011 ◽  
Vol 320 ◽  
pp. 170-175
Author(s):  
Song Bo Yang ◽  
Ming Hua Tang ◽  
Guo Yang Wang ◽  
Bo Jiang ◽  
Hua Yu Xu
Keyword(s):  
Thin Films ◽  
Electrical Properties ◽  
Remnant Polarization ◽  
Ferroelectric Thin Films ◽  
Copolymer Films ◽  
Layer Composite ◽  
Spin Coatings ◽  
Ferroelectric Memory ◽  
Different Thickness ◽  
Coercive Electric Field

The microstructure and electrical properties of P(VDF-TrFE)/Bi3.5Nd0.5Ti3O12bi-layer composite ferroelectric thin films deposited on Pt/Ti/SiO2/Si using two successive spin coatings were investigated. It shows the pores in Bi3.5Nd0.5Ti3O12(BNT) films were effectively suppressed by the presence of P(VDF-TrFE) copolymer films by SEM. The ferroelectric, leakage and dielectric properties of the thin films with different thickness ratio of P(VDF-TrFE) and BNT thin films were measured. With increasing the thickness of P(VDF-TrFE), the remnant polarization, coercive electric field, leakage current density and dielectric constant of thin films were all decreased (except pure P(VDF-TrFE) thin film). Results indicate that the key electrical properties were improved effectively by a little loss of the remnant polarization, which infers potential application in the filed of ferroelectric memory.

scholarly journals Stabilization of Ferroelectric Phase in Highly Oriented Quinuclidinium Perrhenate (HQReO4) Thin Films

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2126
Author(s):  
Junyoung Lee ◽  
Woojun Seol ◽  
Gopinathan Anoop ◽  
Shibnath Samanta ◽  
Sanjith Unithrattil ◽  
...  
Keyword(s):  
Thin Films ◽  
Solution Process ◽  
Intermediate Temperature ◽  
Perovskite Oxide ◽  
Temperature Phase ◽  
Polar Phase ◽  
Practical Applications ◽  
Temperature Range ◽  
Potential Alternative ◽  
Temperature Window

The low-temperature processability of molecular ferroelectric (FE) crystals makes them a potential alternative for perovskite oxide-based ferroelectric thin films. Quinuclidinium perrhenate (HQReO4) is one such molecular FE crystal that exhibits ferroelectricity when crystallized in an intermediate temperature phase (ITP). However, bulk HQReO4 crystals exhibit ferroelectricity only for a narrow temperature window (22 K), above and below which the polar phase transforms to a non-FE phase. The FE phase or ITP of HQReO4 should be stabilized in a much wider temperature range for practical applications. Here, to stabilize the FE phase (ITP) in a wider temperature range, highly oriented thin films of HQReO4 were prepared using a simple solution process. A slow evaporation method was adapted for drying the HQReO4 thin films to control the morphology and the temperature window. The temperature window of the intermediate temperature FE phase was successfully widened up to 35 K by merely varying the film drying temperature between 333 and 353 K. The strategy of stabilizing the FE phase in a wider temperature range can be adapted to other molecular FE materials to realize flexible electronic devices.

Fabrication of V-Substituted (Bi,M)4Ti3O12 [M = Lanthanoids] Thin Films by Chemical Solution Deposition Method

2001 ◽  
Vol 688 ◽  
Author(s):  
H. Uchida ◽  
H. Yoshikawa ◽  
I. Okada ◽  
H. Matsuda ◽  
T. Iijima ◽  
...  
Keyword(s):  
Thin Films ◽  
Chemical Solution Deposition ◽  
Bismuth Titanate ◽  
Ferroelectric Properties ◽  
Ferroelectric Materials ◽  
Processing Temperature ◽  
Chemical Solution ◽  
Si Substrate ◽  
Solution Deposition ◽  
Chemical Solution Deposition Method

AbstractBismuth titanate (Bi4Ti3O12; BIT) -based ferroelectric materials are proposed from the view of the “Site-engineering”, where the Bi-site ions are substituted by lanthanoid ions (La3+ and Nd3+) and Ti-site ions by other ions with higher charge valence (V5+). In the present study, influences of vanadium (V) - substitution for (Bi,M)4Ti3O12 thin films [M = lanthanoid] on the ferroelectric properties are evaluated. V-substituted (Bi,M)4Ti3O12 films have been fabricated using a chemical solution deposition (CSD) technique on the (111)Pt/Ti/SiO2/(100)Si substrate. Remnant polarization of (Bi,La)4Ti3O12 and (Bi,Nd)4Ti3O12 films has been improved by the V-substitution independent of the coercive field. The processing temperature of BLT and BNT films could also be lowered by the V-substitution.

Ferroelectric C-Axis Oriented Pb5Ge3O11 Thin Films for One Transistor Memory Application

1998 ◽  
Vol 541 ◽  
Author(s):  
Tingkai Li ◽  
Fengyan Zhang ◽  
Sheng Teng Hsu
Keyword(s):  
Thin Films ◽  
Ferroelectric Properties ◽  
Hysteresis Loops ◽  
Chemical Vapor ◽  
Dielectric Constants ◽  
Memory Devices ◽  
Leakage Currents ◽  
Fatigue Characteristics ◽  
Ferroelectric Memory ◽  
Memory Applications

AbstractOne transistor memory devices have been proposed recently. To meet the needs of one transistor memory applications, C-axis oriented Pb5Ge3O11 (PGO) thin films were prepared using metalorganic chemical vapor deposition (MOCVD) and rapid thermal processing (RTP). It was found that the nucleation of C-axis Pb5Ge3O11 phase started at a deposition temperature below 400°C and grain growth dominated at 500°C or above. With increasing annealing temperature, the remanent polarization (Pr) and coercive field (Ec) values increased, and the hysteresis loops of the Pb5Ge3O11 films were well saturated and symmetrical after the post-annealing. The C-axis PGO thin film showed good ferroelectric properties at 5V: 2Pr and 2Ec values were 2.0 - 4.0 µC/cm2 and 90 - 110 kV/cm, respectively. The films also showed excellent fatigue characteristics: no fatigue was observed up to 1 × 109 switching cycles. The retention and imprint properties have also been studied. The leakage currents of the PGO films were 2 - 5 × 10−7 A/cm2 at 100 kV/cm and dielectric constants were 40 - 70. The high quality MOCVD Pb5Ge3O11 films can be used for single transistor ferroelectric memory devices.

Sol-Gel derived Bi4-xNdxTi3O12 Thin Films and Their Characterization

2002 ◽  
Vol 737 ◽  
Author(s):  
R.E. Melgarejo ◽  
M.S. Tomar ◽  
A. Hidalgo ◽  
R.S. Katiyar
Keyword(s):  
Thin Films ◽  
Spin Coating ◽  
Bismuth Titanate ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Complete Solid Solution ◽  
Sol Gel Process ◽  
Ferroelectric Memory ◽  
Initial Results

ABSTRACTNd substituted bismuth titanate Bi4-xNdxTi3O12 were synthesized by sol-gel process and thin films were deposited on Pt substrate (Pt/TiO2/SiO2/Si) by spin coating. Thin films, characterized by X-ray diffraction and Raman spectroscopy, shows complete solid solution up to the composition x < 1. Initial results indicate that the ferroelectric polarization increases with increasing Nd content in the film with 2Pr = 50μC/cm2 for x = 0.46, which may have application in non-volatile ferroelectric memory devices.

scholarly journals Temperature-dependent optical and vibrational properties of PtSe2 thin films

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Desman P. Gulo ◽  
Han Yeh ◽  
Wen-Hao Chang ◽  
Hsiang-Lin Liu
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Room Temperature ◽  
Near Infrared ◽  
Technological Development ◽  
Phonon Modes ◽  
Research Attention ◽  
Practical Applications ◽  
Infrared Frequency Range ◽  
Indirect Band Gap

Abstract PtSe2 has received substantial research attention because of its intriguing physical properties and potential practical applications. In this paper, we investigated the optical properties of bilayer and multilayer PtSe2 thin films through spectroscopic ellipsometry over a spectral range of 0.73–6.42 eV and at temperatures between 4.5 and 500 K. At room temperature, the spectra of refractive index exhibited several anomalous dispersion features below 1000 nm and approached a constant value in the near-infrared frequency range. The thermo-optic coefficients of bilayer and multilayer PtSe2 thin films were (4.31 ± 0.04) × 10−4/K and (–9.20 ± 0.03) × 10−4/K at a wavelength of 1200 nm. Analysis of the optical absorption spectrum at room temperature confirmed that bilayer PtSe2 thin films had an indirect band gap of approximately 0.75 ± 0.01 eV, whereas multilayer PtSe2 thin films exhibited semimetal behavior. The band gap of bilayer PtSe2 thin films increased to 0.83 ± 0.01 eV at 4.5 K because of the suppression of electron–phonon interactions. Furthermore, the frequency shifts of Raman-active Eg and A1g phonon modes of both thin films in the temperature range between 10 and 500 K accorded with the predictions of the anharmonic model. These results provide basic information for the technological development of PtSe2-based optoelectronic and photonic devices at various temperatures.

Influence of Bi3.15Nd0.85Ti3O12 Buffer Layer on Structure and Electrical Properties of Bi0.94Ce0.06Fe0.97Ti0.03O3 Thin Films

2014 ◽  
Vol 703 ◽  
pp. 51-55
Author(s):  
Jia Zeng ◽  
Ming Hua Tang ◽  
Zhen Hua Tang ◽  
Yong Guang Xiao ◽  
Long Peng ◽  
...  
Keyword(s):  
Thin Films ◽  
Electrical Properties ◽  
Buffer Layer ◽  
Current Density ◽  
Coercive Field ◽  
Remnant Polarization ◽  
Sol Gel ◽  
Hysteresis Loops ◽  
Si Substrates ◽  
Sol Gel Process

Bi0.94Ce0.06Fe0.97Ti0.03O3 and Bi0.94Ce0.06Fe0.97Ti0.03O3/Bi3.15Nd0.85Ti3O12 double-layered thin films were fabricated via sol-gel process on Pt/Ti/SiO2/Si substrates. The influence of Bi3.15Nd0.85Ti3O12 buffer layer on microstructure and electrical properties of Bi0.94Ce0.06Fe0.97Ti0.03O3 thin films were investigated in detail. Well-saturated P-E hysteresis loops can be obtained in Bi0.94Ce0.06Fe0.97Ti0.03O3 films with Bi3.15Nd0.85Ti3O12 buffer. The remnant polarization (2Pr) of the double-layered thin films is 112 μC/cm2. The coercive field (2Ec) of double-layered films is 672 kV/cm, which is much lower than that of the Bi0.94Ce0.06Fe0.97Ti0.03O3 thin films. The leakage current density of Bi0.94Ce0.06Fe0.97Ti0.03O3/Bi3.15Nd0.85Ti3O12 double-layered thin films is 4.12×10-5 A/cm2.

scholarly journals Engineering of self-rectifying filamentary resistive switching in LiNbO3 single crystalline thin film via strain doping

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Tiangui You ◽  
Kai Huang ◽  
Xiaomeng Zhao ◽  
Ailun Yi ◽  
Chen Chen ◽  
...  
Keyword(s):  
Thin Films ◽  
Resistive Switching ◽  
Schottky Contact ◽  
Homogeneous Distribution ◽  
Single Crystalline ◽  
Wafer Scale ◽  
Practical Applications ◽  
Crystalline Oxide ◽  
Order Of Magnitude ◽  
Switching Characteristics

AbstractThe abilities to fabricate wafer scale single crystalline oxide thin films on metallic substrates and to locally engineer their resistive switching characteristics not only contribute to the fundamental investigations of the resistive switching mechanism but also promote the practical applications of resistive switching devices. Here, wafer scale LiNbO3 (LNO) single crystalline thin films are fabricated on Pt/SiO2/LNO substrates by ion slicing with wafer bonding. The lattice strain of the LNO single crystalline thin films can be tuned by He implantation as indicated by XRD measurements. After He implantation, the LNO single crystalline thin films show self-rectifying filamentary resistive switching behaviors, which is interpreted by a model that the local conductive filaments only connect/disconnect with the bottom interface while the top interface maintains the Schottky contact. Thanks to the homogeneous distribution of defects in single crystalline thin films, highly reproducible and uniform self-rectifying resistive switching with large on/off ratio over four order of magnitude was achieved. Multilevel resistive switching can be obtained by varying the compliance current or by using different magnitude of writing voltage.

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