Studies of Bi4−xGdxTi3O12 Bifunctional Material

2005 ◽  
Vol 888 ◽  
Author(s):  
Maharaj S. Tomar ◽  
Ricardo E. Melgarejo ◽  
Rahúl Singhal ◽  
Luis M. Angelats ◽  
Ram S. Katiyar
Keyword(s):  
Solid Solution ◽  
Spin Coating ◽  
Room Temperature ◽  
Sol Gel ◽  
Magnetic Response ◽  
X Ray Diffraction ◽  
Si Substrate ◽  
X Ray ◽  
Sol Gel Process ◽  
Capacitor Structure

ABSTRACTGadolinium-substituted Bi4Ti3O12 (i.e. Bi4−xGdxTi3O12) were synthesized by sol-gel process for different compositions, and thin films were deposited on Pt (Pt/TiO2/SiO2/Si) substrate by spin coating. Post annealed films at 700° C were investigated for their structural properties using x-ray diffraction and Raman spectroscopy indicating solid solution for compositions: x = 0.00, 0.46, 0.56, and 0.85 where Bi ion is replaced by Gd-ion. Sol-gel derived Pt/Bi4−xGdxTi3O12 film/Pt capacitor structure was tested for dielectric, ferroelectric, and leakage current responses. Films showed ferroelectricity with polarization, Pr = 22 µC/cm2 for composition: x = 0.46. Magnetic response of the powder sample for composition: x = 0.85 was tested using SQUID, which showed superparamagnetic at room temperature and magnetic at 5 K with magnetic coercivity (Hc) = 29 Oe and very small remanance (σr) = 5.4 × 10−4 emu/g.

Preparation of PST Ferroelectric Thin Films by Sol-Gel Process

2013 ◽  
Vol 734-737 ◽  
pp. 2328-2331
Author(s):  
Yu Fei You ◽  
C.H. Xu ◽  
Jing Zhe Wang ◽  
Jun Peng Wang
Keyword(s):  
Thin Films ◽  
Cross Section ◽  
Spin Coating ◽  
Room Temperature ◽  
Sol Gel ◽  
Ferroelectric Thin Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sol Gel Process ◽  
Electronic Microscope

Sol-gel method is used for the formation of Pb0.499Sr0.499TiO3 (PST)thin films. The initial films were prepared with spin coating sol solution on silicon wafer and drying at room temperature and then heating coated dry sol film at 400°C for 10min. This process was repeated for 1-4 times to obtain 4 initial films with different thicknesses. The 4 initial films were annealed at 700°C for 2h to obtain PST ceramics films. The morphologies of the surface and cross-section of PST films were observed with a scanning electronic microscope (SEM). The phase structures of PST films were analyzed using X-ray diffraction meter (XRD). Experimental results show that PST film prepared by coating sol on silicon with different thicknesses can be high smooth,uniform and compact film.

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.

Synthesis and Characterizations of Strontium Substituted Hydroxyapatite Thin Films

2010 ◽  
Vol 93-94 ◽  
pp. 231-234
Author(s):  
B. Hongthong ◽  
Satreerat K. Hodak ◽  
Sukkaneste Tungasmita
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Chemical Composition ◽  
Spin Coating ◽  
Phase Structure ◽  
Sol Gel ◽  
Cross Linking ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sol Gel Process

Strontium substituted hydroxyapatite(SrHAp) were fabricated both in the form of powder as reference and thin film by using inorganic precursor reaction. The sol-gel process has been used for the deposition of SrHAp layer on stainless steal 316L substrate by spin coating technique, after that the films were annealed in air at various temperatures. The chemical composition of SrHAp is represented (SrxCa1-x)5(PO4)3OH, where x is equal to 0, 0.5 and 1.0. Investigations of the phase structure of SrHAp were carried out by using X-ray diffraction technique (XRD). The results showed that strontium is incorporated into hydroxyapatite where its substitution for calcium increases in the lattice parameters, and Sr3(PO4)2 can be detected at 900°C. The SEM micrographs showed that SrHAp films exhibited porous structure before develop to a cross-linking structure.

Structural, Magnetic, and Electrical Properties of BiFe1-xMnxO3 Thin Films

2009 ◽  
Vol 1199 ◽  
Author(s):  
Danilo G Barrionuevo ◽  
Surinder P Singh ◽  
Maharaj S. Tomar
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Magnetic Measurements ◽  
Sol Gel ◽  
Ion Concentration ◽  
Ferromagnetic Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Si Substrates ◽  
Sol Gel Process

AbstractWe synthesized BiFe1-xMnxO3 (BFMO) for various compositions by sol gel process and thin films were deposited by spin coating on platinum Pt/Ti/SiO2/Si substrates. X-ray diffraction shows all the diffraction planes corresponding to rhombohedrally distorted perovskite BiFeO3 structure. The absence of any impurity phase in the films suggests the incorporation Mn ion preferentially to Fe site in the structure for low concentration. Magnetic measurements reveal the formation of ferromagnetic phase at room temperature with increased Mn substitution. On the other hand, ferroelectric polarization decreases with increasing Mn ion concentration. Raman studies suggest the dopant induced structural distortion.

Investigation of hydration phases in the system CaO–SiO2-P2O5-H2O

1988 ◽  
Vol 3 (4) ◽  
pp. 772-780 ◽  
Author(s):  
Jiashan Hu ◽  
D. K. Agrawal ◽  
R. Roy
Keyword(s):  
Room Temperature ◽  
Sol Gel ◽  
Hydration Products ◽  
X Ray Diffraction ◽  
Hydrothermal Conditions ◽  
X Ray ◽  
Sol Gel Process ◽  
Structural Nature ◽  
Amorphous Powders ◽  
Hydration Phases

Hydration reactions and their rates have been studied qualitatively in CaO-and P2O5-rich compositional regions of the system CaO–SiO2-P2O5-H2O. Using aqueous solutions of Ca (NO3)2–4H2O, Ludox, and H3PO4 as starting materials, amorphous powders made by the sol-gel process were reacted with water. Some “curing” reactions were carried out at several temperatures: room temperature, 90 °C, and under hydrothermal conditions. Some glasses in the phosphate-rich region of the system were also made and hydrated. The hydration products are OH–Ap [OH–Ap = Ca10(PO4)6-(OH)2], Ca(OH)2 [CH = Ca(OH)2],C–S–H crystalline, C–S–P–H (C = CaO,S = SiO2,P = P2O5,H = H2O) crystalline, C–S–H gel, C–S–P–H gel, Ca(H2PO4)2·H2O, and CaHPO4. All phases have been identified and characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive x-ray analysis (EDAX). The reactivities of the precursor materials and the compositional-structural nature of the hydration products formed are discussed. Some new compositions for “cementlike behavior” have been discovered.

scholarly journals Erbium upconversion luminescence from sol–gel derived multilayer porous inorganic perovskite film

2022 ◽  
Author(s):  
M. V. Rudenko ◽  
N. V. Gaponenko ◽  
E. B. Chubenko ◽  
E. I. Lashkovskaya ◽  
K. V. Shustsikava ◽  
...  
Keyword(s):  
Room Temperature ◽  
Upconversion Luminescence ◽  
Sol Gel ◽  
Perovskite Solar Cells ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Si Substrate ◽  
X Ray ◽  
Erbium Doped ◽  
Doped Barium Titanate

Erbium-doped barium titanate (BaTiO3:Er) xerogel film with a thickness of about 500 nm was formed on the porous strontium titanate (SrTiO[Formula: see text] xerogel film on Si substrate after annealing at 800[Formula: see text]C or 900[Formula: see text]C. The elaborated structures show room temperature upconversion luminescence under 980 nm excitation with the photoluminescence (PL) bands at 523, 546, 658, 800 and 830 nm corresponding to 2H[Formula: see text]4I[Formula: see text], 4S[Formula: see text]I[Formula: see text], 4F[Formula: see text]I[Formula: see text] and 4I[Formula: see text]4I[Formula: see text] transitions of trivalent erbium. Raman and X-ray diffraction (XRD) analysis of BaTiO3:Er\porous SrTiO3\Si structure showed the presence of perovskite phases. Its excellent up-conversion optical performance will greatly broaden its applications in perovskite solar cells and high-end anti-counterfeiting technologies.

scholarly journals Bulk heterojunction blend (NiPcTs:PEDOT:PSS) in gas sensing

2019 ◽  
Vol 15 (32) ◽  
pp. 31-42
Author(s):  
Morooj A. Abood
Keyword(s):  
Thin Films ◽  
Spin Coating ◽  
Room Temperature ◽  
Gas Sensing ◽  
Bulk Heterojunction ◽  
Good Sensitivity ◽  
Good Information ◽  
X Ray Diffraction ◽  
Si Substrate ◽  
X Ray

Thin films of bulk heterojunction blend Ni-PhthalocyanineTetrasulfonic acid tetrasodium salt and dpoly(3, 4-ethylenedioxythiophene) poly (styrenesulfonate) (NiPcTs:PEDOT: PSS) with different (PEDOT:PSS) concentrations (0.5, 1, 2)are prepared using spin coating technique with thickness 100 nm onglass and Si substrate. The X-Ray diffraction pattern of NiPcTspowder was studied and compared with NiPc powder, the patternshowed that the structure is a polycrystalline with monoclinic phase.XRD analysis of as-deposited (NiPcTs/PEDOT:PSS) thin filmsblends in dicated that the film appeared at(100), (102) inconcentrations (0.5, 1) and (100) in concentration (2). The grain sizeis increased with increasing (PEDOT:PSS) concentrations. FTIRmeasurements for these bulk heterojunction blend thin films alsocarried out in this work and gave good information about the bondsand their locations. Sensor measurements of Si/NiPcTS:PEDOT:PSSbulk heterojunctions blend thin films show a good sensitivity for NO2gas Compared to NH3gas. The NiPcTS/PEDOT:PSS gas sensordevice work at room temperature than high temperature for NO2 gasbut good sensitivity at100ºC for NH3 gas and sensor work moreeffectively in 0.5 concentration for both gases.

Effect of Annealing temperature on the Structural and Magnetic Properties of TbxY3-xFe5O12(x = 0.0, 1.0, 2.0) Thin Films Prepared by Sol-Gel Process

2012 ◽  
Vol 501 ◽  
pp. 236-241 ◽  
Author(s):  
Ftema W. Aldbea ◽  
Noor Bahyah Ibrahim ◽  
Mustafa Hj. Abdullah ◽  
Ramadan E. Shaiboub
Keyword(s):  
Thin Films ◽  
Magnetic Properties ◽  
Room Temperature ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Vibrating Sample Magnetometer ◽  
X Ray ◽  
Garnet Phase ◽  
Sol Gel Process ◽  
Amorphous Structures

Thin films nanoparticles TbxY3-xFe5O12 (x=0.0, 1.0, 2.0) were prepared by the sol-gel process followed by annealing process at various annealing temperatures of 700° C, 800° C and 900° C in air for 2 h. The results obtained from X-ray diffractometer (XRD) show that the films annealed below 900°C exhibit peaks of garnet mixed with small amounts of YFeO3 and Fe2O3. Pure garnet phase has been detected in the films annealed at 900°C. Before annealing the films show amorphous structures. The particles sizes measurement using the field emission scanning electron microscope (FE-SEM) showed that the particles sizes increased as the annealing temperature increased. The magnetic properties were measured at room temperature using the vibrating sample magnetometer (VSM). The saturation magnetization (Ms) of the films also increased with the annealing temperature. However, different behavior of coercivity (Hc) has been observed as the annealing temperature was increased.

Luminescent Properties of Zn2SiO4:Eu3+,Dy3+ Phosphors via Sol-Gel Process

2012 ◽  
Vol 217-219 ◽  
pp. 733-736
Author(s):  
Xiu Mei Han ◽  
Shu Ai Hao ◽  
Ying Ling Wang ◽  
Gui Fang Sun ◽  
Xi Wei Qi
Keyword(s):  
Thermal Analysis ◽  
Ir Spectra ◽  
Sol Gel ◽  
Luminescent Properties ◽  
Photoluminescence Spectra ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sol Gel Process ◽  
Ft Ir

Zn2SiO4:Eu3+, Dy3+ phosphors have been prepared through the sol-gel process. X-ray diffraction (XRD), thermogravimetric and ddifferential thermal analysis (TG-DTA), FT-IR spectra and photoluminescence spectra were used to characterize the resulting phosphors. The results of XRD indicated that the phosphors crystallized completely at 1000oC. In Zn2SiO4:Eu3+,Dy3+ phosphors, the Eu3+ and Dy3+ show their characteristic red(613nm, 5D0-7F2), blue (481nm, 4F9/2–6H15/2) and yellow (577nm, 4F9/2–6H13/2) emissions.

Impedance Spectroscopy Study of LiTaO3 Powder Synthesized via Sol-Gel Method

2012 ◽  
Vol 545 ◽  
pp. 275-278 ◽  
Author(s):  
Lili Widarti Zainuddin ◽  
Norlida Kamarulzaman
Keyword(s):  
Room Temperature ◽  
Single Phase ◽  
Sol Gel ◽  
Rhombohedral Structure ◽  
Spectroscopy Study ◽  
X Ray Diffraction ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Impedance Spectroscopy Study

A ceramics sample of LiTaO3 was prepared using a sol-gel method. The sample is annealed at 750 °C for 48 hours. X-ray diffraction analysis indicate the formation of single phase, rhombohedral structure. An ac impedance study was used to analyse the conductivity of LiTaO3 at room temperature and at various temperatures.

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