scholarly journals Influence of Crystallization Temperature on Structural, Ferroelectric, and Ferromagnetic Properties of Lead-Free Bi0.5(Na0.8K0.2)0.5TiO3 Multiferroic Films

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Ngo Duc Quan ◽  
Tran Quoc Toan ◽  
Vu Ngoc Hung ◽  
Minh-Duc Nguyen
Keyword(s):  
Crystallization Temperature ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Lead Free ◽  
Ferromagnetic Behavior ◽  
Si Substrates ◽  
Different Temperatures ◽  
Multiferroic Films ◽  
Influence Of Crystallization ◽  
Free Films

Lead-free Bi0.5(Na0.8K0.2)0.5TiO3 (abbreviated as BNKT) films have been synthesized via a sol-gel technique on Pt/Ti/SiO2/Si substrates, and the dependence of the physical properties in BNKT films were investigated as a function of the crystallization temperature. The BNKT films were annealed at different temperatures (600, 650, 700, and 750°C) for 60 min in the air. The results of this study showed that the optimal crystallization temperature is 700°C. At this, the BNKT films exhibited a single perovskite phase structure and high-dense surface. Besides, the remanent (Pr) and maximum (Pm) polarization reached their highest values of 9.2 µC/cm2 and 30.6 µC/cm2, respectively. All the films showed a weak ferromagnetic behavior with the maximum saturated magnetization (Ms) of 2.1 emu/cm3. These values are equivalent to the highest Pr and Pm values in previous reports on lead-free films.

Effects of Sputter-Deposited LaNiO3 Electrode on the Deposition and Properties of Ferroelectric Thin Films

1996 ◽  
Vol 433 ◽  
Author(s):  
T. B. Wu ◽  
J. M. Wu ◽  
C. M. Wu ◽  
M. J. Shyu ◽  
M. S. Chen ◽  
...  
Keyword(s):  
Thin Films ◽  
Magnetron Sputtering ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Processing Condition ◽  
Fatigue Property ◽  
Rf Magnetron Sputtering ◽  
Ferroelectric Films ◽  
Si Substrates ◽  
Sputter Deposited

AbstractHighly (100)-textured thin film of metallic LaNiO3 (LNO) was grown on the Pt/Ti/SiO2/Si substrates by rf magnetron sputtering at ˜300°C, which was used as a bottom electrode to prepare highly (100)-textured ferroelectric films. Examples on the deposition of PbTiO3, (Pbl−xLax)TiO3, Pb(Zr0.53Ti0.47)O3, Pb[(Mg1/3Nb2/3)1−xTix]O3, and (Ba1−xSrx)TiO3 thin films by rf magnetron sputtering or sol-gel method are shown. A reduction of temperature for perovskite phase formation can be achieved, especially for those difficult to crystallize. The surface roughness of the ferroelectric films is also improved as compared to that of films deposited on conventional Pt electrode. Although the electrical properties of the ferroelectric films are affected by the out-diffusion of LNO when a higher temperature was used in the preparation of the films, under an appropriate processing condition, the highly (100)-textured films can have satisfactory electrical characteristics for application. Moreover, the polarization-fatigue property can be also improved by the use of LNO electrode.

LUMINESCENT PROPERTIES OF SOL-GEL DEPOSITED Eu:TiO2 THIN FILMS

2001 ◽  
Vol 15 (17n19) ◽  
pp. 769-773 ◽  
Author(s):  
M. GARCIA-ROCHA ◽  
A. CONDE-GALLARDO ◽  
I. HERNANDEZ-CALDERON ◽  
R. PALOMINO-MERINO
Keyword(s):  
Thin Films ◽  
Sol Gel ◽  
Luminescent Properties ◽  
X Ray Diffraction ◽  
Si Substrates ◽  
Glass Substrates ◽  
Corning Glass ◽  
Different Temperatures ◽  
Hecd Laser

In this work we show the results on tile growth and optical characterization of TiO 2 thin films doped with Eu atoms. Eu:TiO2 films were grown at room temperature with different Eu concentrations by sol-gel on Si Corning glass substrates. A different crystalline structure is developed for the films deposited on Corning glass than those deposited on Si as observed from x-ray diffraction experiments. Room and low temperature photoluminescence (PL) was measured by using two different lines (325 and 442 nm) of a HeCd laser. A strong PL signal associated to the 5 D 0→7 F 2 transition from Eu +3 was observed. A better emission was obtained from those films deposited on Si substrates, Finally, the evolution of the PL signal is studied when the samples are annealed at different temperatures in O 2 atmosphere.

Composition dependence of phase structure and electrical properties of BiMnO3-modified Bi0.5(Na0.8K0.2)0.5TiO3 thin films

RSC Advances ◽  
2015 ◽  
Vol 5 (77) ◽  
pp. 62713-62718 ◽  
Author(s):  
Peng Li ◽  
Wei Li ◽  
Jiwei Zhai ◽  
Bo Shen ◽  
Huarong Zeng ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Thin Films ◽  
Electrical Properties ◽  
Phase Structure ◽  
Composition Dependence ◽  
Sol Gel ◽  
Lead Free ◽  
Gel Method ◽  
Sol Gel Method ◽  
Si Substrates

Lead-free (1 − x)Bi0.5(Na0.8K0.2)0.5TiO3-xBiMnO3 (BNKT-xBMO, 0 < x < 0.025) thin films were deposited on Pt/Ti/SiO2/Si substrates by a sol–gel method, and the effects of BiMnO3 addition on the crystal structure and electrical properties were systematically investigated.

Perovskite crystallization of sol-gel processed (Pb,La0.06,Gd0.02)(Zr0.65,Ti0.35)O3 thin films: Dielectric, ferroelectric and optical properties

2002 ◽  
Vol 17 (10) ◽  
pp. 2652-2659 ◽  
Author(s):  
Reji Thomas ◽  
Shoichi Mochizuki ◽  
Toshiyuki Mihara ◽  
Tadashi Ishida
Keyword(s):  
Thin Films ◽  
Refractive Index ◽  
Sol Gel ◽  
Band Gap Energy ◽  
Elemental Distribution ◽  
Surface And Interface ◽  
Si Substrates ◽  
Dielectric Constant And Loss ◽  
Direct Band ◽  
Free Films

Ferroelectric lead lanthanum gadolinium zirconium titanate (PLGZT) thin films were prepared by the sol-gel spin coating technique. Three-step preannealing heat treatment was employed to prepare crack-free films. Various types of substrates, and the effects of the seed layer and annealing temperature on the perovskite crystallization were studied. Phase-pure perovskite crystallization was obtained by annealing the films on PbTiO3/Pt/Ti/Si substrates at 700 °C for 30 min. The Auger electron spectroscopy depth profile showed uniform elemental distribution along the thickness except the surface and interface regions. Dielectric constant and loss tangent at 10 kHz were 1000 and 0.06, respectively. Remanent polarization (Pr) and coercive field (Ec) were 11.8 μC/cm2 and 71 kV/cm, respectively. The direct band gap energy was 3.55 eV for the amorphous films. The refractive index and extinction coefficient at 610 nm for amorphous PLGZT films were 2.14 and 0.0028, respectively. The dispersion of the refractive index was interpreted in terms of a single electronic oscillator at 6.06 eV.

Hydrogen Gas Sensing Characterizations Based on Nanocrystalline SnO2 Thin Films Grown on SiO2/Si and Al2O3 Substrates

2017 ◽  
Vol 268 ◽  
pp. 244-248
Author(s):  
Abu Hassan Haslan ◽  
Imad Hussein Kadhim
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Gas Sensing ◽  
Sol Gel ◽  
Hydrogen Gas ◽  
Rutile Structure ◽  
Nanoparticle Distribution ◽  
Si Substrates ◽  
Coating Method ◽  
Different Temperatures

High-quality nanocrystalline (NC) SnO2 thin films were grown on SiO2/Si and Al2O3 substrates using sol–gel spin coating method. The structural properties, surface morphologies and gas sensing properties of the NC SnO2 were investigated. XRD measurements showed a tetragonal rutile structure and the diffraction peaks for NC SnO2 thin films grown on Al2O3 substrates outperformed those of NC SnO2 films grown on SiO2/Si substrates. The surface morphology of the annealed SnO2 thin films at 500 °C appeared as polycrystalline with uniform nanoparticle distribution. Hydrogen (H2) gas sensing performance of the NC SnO2 was examined for H2 concentrations ranging from 150 ppm to 1000 ppm at different temperatures (room temperature, 75 and 125 °C) for over 50 min. The room temperature sensitivities for H2 gas sensors based on NC SnO2 thin films grown on Al2O3 and SiO2/Si substrates was 2570% and 600%, respectively upon exposure to 1000 ppm of H2 gas. While the sensitivity values at 125 °C increased to 9200% and 1950%, respectively.

Effect of Structural Deficiencies on Bi-Ferroic Behaviors of Lead-Free Bi0.5 Na0.40K0.10TiO3 Films

2021 ◽  
Vol 21 (11) ◽  
pp. 5653-5658
Author(s):  
Ngo Due Quan ◽  
Nguyen Due Minh ◽  
Hoang Viet Hung
Keyword(s):  
Magnetic Properties ◽  
Annealing Time ◽  
Spin Coating ◽  
Applied Electric Field ◽  
Remnant Polarization ◽  
Oxygen Vacancies ◽  
Sol Gel ◽  
Lead Free ◽  
Ferroelectric Films ◽  
Si Substrates

Lead-free Bi0.5Na0.4K0.1TiO3 (BNKT) ferroelectric films on Pt/TI/SIO2/Si substrates were prepared via a sol-gel spin coating routine. The microstructures and multiferroic behaviors of the films were examined intimately as a function of the annealing time. A rise of annealing time enhanced the crystallization of the films via the perovskite structure. The multiferroic behavior, including simultaneously the magnetic and ferroelectric orders, was observed altogether the films. When the annealing time rose, ferroelectric and magnetic properties were found significantly increased. The remnant polarization (Pr), also as maximum polarization (Pm) respectively increased to the very best values of 11.5 µC/cm2 and 40.0 µC/cm2 under an applied electric field of 500 kV/cm. The saturated magnetization (Ms) of films increased to 2.3 emu/cm3 for the annealing time of 60 minutes. Oxygen vacancies, originating from the evaporation of metal ions during annealing at high temperatures are attributed to the explanation for ferromagnetism within the BNKT films.

OPTIMIZATION OF PROCESSING TEMPERATURE TO ACHIEVE HIGH QUALITY SOL–GEL-DERIVED PZT THIN FILM

2009 ◽  
Vol 08 (03) ◽  
pp. 299-303 ◽  
Author(s):  
SAJJAD DEHGHANI ◽  
ABDOLGHAFAR BARZEGAR ◽  
MOHAMMAD HOSSEIN SHEIKHI
Keyword(s):  
Thin Films ◽  
Spin Coating ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Morphological Properties ◽  
Processing Temperature ◽  
High Quality ◽  
Pzt Thin Films ◽  
Polarization Voltage ◽  
Si Substrates

Ferroelectric PbZr 1-x Ti x O 3 (PZT) thin films have been extensively investigated because of their excellent piezoelectric, pyroelectric, ferroelectric, and dielectric properties. Sol–gel synthesis and spin-coating are popular routes to the formation of high quality, dense, and crack-free thin films. In this work, high quality, crack-free PZT thin films have been prepared by sol–gel method via spin-coating on Pt/Ti/SiO2/Si substrate by different temperature processings. The crystallographic and morphological properties of the films have been analyzed by X-ray diffraction and scanning electron microscopy. The electrical properties of thin films including the permittivity, loss tangent, and polarization–voltage hysteresis loop were measured and compared for different films. Finally, by optimizing temperature processing, highly textured and high quality films of PZT with perovskite phase were obtained on Pt/Ti/SiO2/Si substrates.

Preparation of (K,Na)NbO3 Powders with Wide Grain Size Distribution

2017 ◽  
Vol 898 ◽  
pp. 1603-1610 ◽  
Author(s):  
Yu Hua Zhen ◽  
Kai Li Jia ◽  
Lin Ling Li ◽  
Yu Xi Qiao ◽  
Fu Hua Sun ◽  
...  
Keyword(s):  
Grain Size ◽  
Molten Salt ◽  
Size Distribution ◽  
Grain Size Distribution ◽  
Crystallization Temperature ◽  
Sol Gel ◽  
Lead Free ◽  
Molten Salt Method ◽  
Powder Morphology ◽  
Experimental Parameters

This study is aimed at obtaining (K,Na)NbO3 powders with wide grain size distribution methods. (K,Na)NbO3 powders were successfully synthesized by different ways, including hydrothermal method, sol-gel method, and molten-salt method. The experiment results showed that the hydrothermal and sol-gel methods could not control the grain size of the (K,Na)NbO3 powders effectively . The grain size of (K,Na)NbO3 powders can be only tailored by the molten-salt method through controlling the starting oxide powder morphology, as well as crystallization temperature. The grain size was not affected by the experimental parameters whether or not the initial powders were milled. Furthermore, it has been found that the crystallization temperature could change the grain size of the powders monotonously. The (K,Na)NbO3 powders synthesized by molten salt method distributed from nanoscale to micron level, which can lay the foundation for further research on the grain size effect of (K,Na)NbO3 lead free piezoelectric ceramics.

Synthesis and Properties of Lead Free Ferroelectric Na0.5Bi0.5TiO3 Ceramic at Different Sintering Temperature

2015 ◽  
Vol 830-831 ◽  
pp. 620-623 ◽  
Author(s):  
Kusum Parmar ◽  
Hakikat Sharma ◽  
Sarita Sharma ◽  
N.S. Negi
Keyword(s):  
Phase Transition ◽  
Room Temperature ◽  
Sintering Temperature ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
Lead Free ◽  
Characteristic Absorption Band ◽  
Different Temperatures ◽  
Xrd Patterns ◽  
Rhombohedral Symmetry

Lead Free Ferroelectric Na0.5Bi0.5TiO3 (NBT) Ceramic has been synthesized using sol gel method. The prepared NBT samples have been sintered at different temperatures 850°C, 950°C, 1050°C and 1150°C to achieve best sintering temperature. Structural analyses have been carried out using XRD and FTIR measurements. XRD patterns confirm perovskite structure having rhombohedral symmetry for all samples which is also supported by characteristic absorption band at ~627cm-1 in FTIR spectra. Dielectric properties of NBT samples with frequency and temperature have been studied. NBT sample sintered at 1050°C exhibit comparatively high value of dielectric constant (ε’) and phase transition temperature (Tm). Ferroelectric properties of NBT samples have been studied at room temperature. Comparatively, better ferroelectric properties are observed for NBT sample having remnant polarization (Pr)~ 14.7 μC/cm2and coercive field (Ec)~ 26.8 kV/cm sintered at 1050°C.

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