Low-temperature fabrication of pyroelectric Ba0.8Sr0.2TiO3 thin films by a sol-gel process

2001 ◽  
Vol 16 (3) ◽  
pp. 778-783 ◽  
Author(s):  
Jian-Gong Cheng ◽  
Jun Tang ◽  
Shao-Ling Guo ◽  
Jun-Hao Chu
Keyword(s):  
Perovskite Phase ◽  
Sol Gel ◽  
Pyroelectric Coefficient ◽  
X Ray Diffraction ◽  
Electrical Measurements ◽  
Pure Perovskite Phase ◽  
Average Grain Size ◽  
Sol Gel Process ◽  
Columnar Grains ◽  
Uncooled Infrared Detectors

Ba0.8Sr0.2TiO3 films were fabricated with a 0.05 M solution by a sol-gel process at temperatures between 550 and 650 °C. Analysis by x-ray diffraction, Raman spectroscopy, and scanning electron microscopy revealed that the films annealed at 650 °C showed pure perovskite phase, tetragonal structure, and columnar grains with an average grain size of 150 nm. Electrical measurements performed on the films annealed at 650 °C showed two dielectric peaks in the dielectric constant–temperature curve, a remnant polarization of 1.4 μC/cm2, a coercive field of 18.3 kV/cm, and good insulating property. The measured pyroelectric coefficient for the films annealed at 650 °C was larger than 3.1 × 10−4 C/m2K at the temperatures ranging from 10 to 26 °C and reached the maximum value of 4.1 × 10−4 C/m2K at 16 °C. The excellent pyroelectric property rendered the Ba0.8Sr0.2TiO3 films annealed at 650 °C promising for uncooled infrared detectors and thermal imaging applications.

Preparation and Mechanical Properties of BiFeO3 Ceramics

2016 ◽  
Vol 697 ◽  
pp. 293-296
Author(s):  
Xiao Yang Zhang ◽  
Xi Wei Qi ◽  
Zhi Yuan Yang ◽  
Li Bao ◽  
Min Zhang
Keyword(s):  
Mechanical Properties ◽  
Hydrothermal Method ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Cold Isostatic Pressing ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Three Point Bending ◽  
Multiferroic Bifeo ◽  
Sol Gel Process

Hydrothermal method and sol-gel process were used to synthesize multiferroic BiFeO3 ceramics. X-ray diffraction, scanning electron microscopy, vickers diamond indenter and three-point bending method were used to investigate the effects of methods on the phase structure, microstructures and mechanical properties. Cold isostatic pressing on the ceramics with two different loads (10 MPa, 200 MPa) was used to illustrate the influence of pressure in mechanical properties. The results show that all samples are crystallized in the perovskite phase. A few small traces of impurity are observed at a 2θ of ~28 o, which are found to be those of Bi2Fe4O9. The SEM images depict that samples prepared by sol-gel process are more uniform and the grain size is slightly larger than that of hydrothermal processed samples. The investigations on the hardness and flexural strength demonstrate the ceramics prepared by hydrothermal method have better mechanical properties than that of sol-gel process, and the mechanical properties can be obviously enhanced by increasing pressure.

Luminescence properties of R2MoO6:Eu3+ (R = Gd, Y, La) phosphors prepared by Pechini sol-gel process

2005 ◽  
Vol 20 (10) ◽  
pp. 2676-2681 ◽  
Author(s):  
Maolin Pang ◽  
Xiaoming Liu ◽  
Jun Lin
Keyword(s):  
Grain Size ◽  
Sol Gel ◽  
Luminescent Properties ◽  
Luminescence Properties ◽  
X Ray Diffraction ◽  
Powder Morphology ◽  
X Ray ◽  
Average Grain Size ◽  
Sem Study ◽  
Sol Gel Process

R2MoO6:Eu3+ (R = Gd, Y, La) phosphors were prepared by the Pechini sol-gel process. X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), reflectance spectra, photoluminescence (PL) spectra, and lifetimes were used to characterize the resulting phosphors. The results of XRD indicate that all of the R1.96Eu0.04MoO6 (R = Gd, Y, La) phosphors crystallized completely at 800 °C. Y1.96Eu0.04MoO6 and Gd1.96Eu0.04MoO6 are of isomorphous monoclinic (α) structure, while La1.96Eu0.04MoO6 preferentially adopts the tetragonal (γ) form. FE-SEM study reveals that the samples mainly consist of aggregated particles with an average grain size ranging from 100 to 250 nm. The luminescent properties of R2MoO6:Eu3+ (R = Gd, Y, La) phosphors are largely dependent on their structure, grain size, and powder morphology. The isomorphous Y2MoO6:Eu3+ and Gd2MoO6:Eu3+ phosphors show very similar luminescence properties, which differ greatly from that of the La2MoO6:Eu3+ phosphor.

Structure and Dielectric Properties of Mn, Co, and Ni-Doped LaSrFeO3 Films

2013 ◽  
Vol 575-576 ◽  
pp. 499-503
Author(s):  
Bin Fu ◽  
Yang Lu Hou ◽  
Wei Bing Wu ◽  
Xing Hua Fu
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Dielectric Properties ◽  
Smooth Surface ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Electrical Measurements ◽  
Doping Amount ◽  
Pure Perovskite Phase ◽  
Gel Technique

Mn, Co, and Ni-doped La0.5Sr0.5FeO3thin films were prepared by the sol-gel technique. The structure and dielectric properties of the films were studied by XRD, SEM, and electrical measurements. The morphology observation demonstrated these films had uniform grain size and smooth surface. The dielectric properties of La0.5Sr0.5FeO3films were improved by the replacement of Fe with Mn, Co, and Ni. The doping amount of Mn, Co, and Ni for the optimal dielectric properties of La0.5Sr0.5FeO3films is 5%, 2%, and 3%, respectively. The observed pure perovskite phase of the doped films suggested the dissolution of Mn, Co, and Ni in La0.5Sr0.5FeO3crystal lattice.

Preparation of PZT Material with Different Zi/Ti Ratio by Sol-Gel Method

2012 ◽  
Vol 238 ◽  
pp. 105-108 ◽  
Author(s):  
Xi Chen
Keyword(s):  
Lead Zirconate Titanate ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Lead Zirconate ◽  
Synthesis Temperature ◽  
X Ray Diffraction ◽  
Pure Perovskite Phase ◽  
Gel Technique ◽  
Relationship Of ◽  
The Relationship

Lead zirconate titanate powders (PZT) with different Zi/Ti values 52/48, 53/47, 54/46 and 55/45 were prepared by sol-gel technique. The sol was prepared by mixing stable solutions of Zr-nitrate, Pb-acetate and Ti (OC4H9)4 precursors. The decomposition of precursors above 773 K, 923 K and 1073 K for Zi/Ti value equls to 52/48; 53/47 and 54/46; 55/45 leads to the formation of pure perovskite phase, respectively. X-ray diffraction analysis was carried out to confirm the phase formation of PZT. The relationship of synthesis temperature and Zi/Ti ratio value is disscused and it is found that higher synthesis temperature is needed to prepare pure PZT with increasing Zi/Ti ratio.

Sol-Gel Deposition and Luminescence Properties of Spherical Phosphors Ca2Y8(SiO4)6O2:Eu3+

2008 ◽  
Vol 368-372 ◽  
pp. 378-380
Author(s):  
Xiu Mei Han ◽  
J. Lin ◽  
M. Yu ◽  
C.K. Lin ◽  
Xi Wei Qi ◽  
...  
Keyword(s):  
Grain Size ◽  
Charge Transfer ◽  
Diffraction Analysis ◽  
Charge Transfer Band ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Red Emission ◽  
X Ray ◽  
Average Grain Size ◽  
Sol Gel Process

Spherical SiO2 particles were coated with Ca2Y8(SiO4)6O2:Eu3+ phosphor layers through a sol-gel process. The results of XRD (X-ray diffraction) analysis indicated that the phosphors crystallized completely at 1000oC. AFM study revealed that the average grain size is 500 nm. In Ca2Y8(SiO4)6O2:Eu3+ spherical phosphors , the Eu3+ showed its characteristic red emission at 612 nm(5D0-7F2) upon excitation into its charge transfer band of Eu3+-O2- at 242nm.

Preparation of Perovskite Conductive LaNiO3 Films by Sol-Gel Techniques

2006 ◽  
Vol 933 ◽  
Author(s):  
Pei-Ying Lai ◽  
Jen-Sue Chen
Keyword(s):  
Thin Films ◽  
Photoelectron Spectroscopy ◽  
Raw Materials ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Metallic Thin Films ◽  
X Ray Diffraction ◽  
Electrical Measurements ◽  
Metallic Oxide ◽  
X Ray

ABSTRACTMetallic thin films of LaNiO3 (LNO) have been prepared by the sol-gel method using lanthanum nitrate [La(NO3)3·6H2O] and nickel acetate [Ni(CH3COO)2·4H2O] as raw materials. X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, and electrical measurements were used to characterize the multilayer LNO thin films. The perovskite phase appears after annealing at temperatures above 600 °C. LNO thin films are n-type metallic oxide. The lowest resistivity is 621 °Ω-cm after annealing at 600 °C, and the carrier concentration is 6.09×1022/cm3.

Sol-Gel Processing and Novel Physical Properties of PLZT 7/57/43 Ferroelectric Ceramics

2013 ◽  
Vol 873 ◽  
pp. 292-297 ◽  
Author(s):  
Ke Yu Zheng ◽  
Ya Li Ding ◽  
Ren Zhi Shao
Keyword(s):  
Physical Properties ◽  
Piezoelectric Properties ◽  
Perovskite Phase ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
Ferroelectric Ceramics ◽  
Nominal Composition ◽  
Electrical Measurements ◽  
Sol Gel Process ◽  
Dta Studies

The sol-gel process was employed to prepare (Pb1-xLax)(Zr1-yTiy)O3(PLZT) ceramics with nominal composition Pb0.93La0.07(Zr0.57Ti0.43)0.9825O3. The structure and physical properties such as dielectric, piezoelectric and ferroelectric properties were investigated. X-ray diffraction results showed that the perovskite phase PLZT was formed when the sol-gel processed powders was calcined at 600°Cfor 4 hours. nanocrystalline particles with a size of ~50nm were found. TG-DTA studies were used to analyze the thermal properties of nanopowders for understanding the reaction kinetics in them. Wafered bulk ceramic samples prepared from the sol-gel derived powders were subjected to electrical measurements, in order to determine the dielectric, piezoelectric and ferroelectric properties. The dielectric properties of the PLZTBST system are further improved and the dielectric piezoelectric properties of PLZT ceramics are found to be sensitive to the particle size of PLZT nanopowders. The dielectric piezoelectric properties of polarized PLZT ceramics can be improved with the lessening of PLZT nanopowder size. Meanwhile, the grain size of PLZT ceramics decreases.

MICROSTRUCTURES AND PIEZOELECTRIC PROPERTIES OF KNNLST DOPING BCZT LEAD-FREE CERAMICS

2012 ◽  
Vol 05 (04) ◽  
pp. 1250041 ◽  
Author(s):  
WEI XU ◽  
YANG LI ◽  
JIAN-MIN FENG ◽  
YE-JING DAI
Keyword(s):  
Piezoelectric Properties ◽  
Perovskite Phase ◽  
Lead Free ◽  
X Ray Diffraction ◽  
X Ray ◽  
Practical Applications ◽  
Lead Free Ceramics ◽  
Pure Perovskite Phase ◽  
Average Grain Size ◽  
Piezoelectric Behavior

In this study, lead-free piezoelectric ceramics ( Na0.52K0.44Li0.04 )( Nb0.88Sb0.08Ta0.04 ) O3 -doped 0.52 Ba ( Zr 0.2 Ti 0.8) O 3-0.48( Ba 0.7 Ca 0.3) TiO 3( BCZT -x KNNLST ) are investigated. The effects of the KNNLST addition on the microstructures and the electrical properties of the ceramics sintered at the temperature as low as 1350°C are studied. The X-ray diffraction data show that the addition of KNNLST could diffuse into BCZT lattice and a pure perovskite phase is formed. With the increase of KNNLST addition, the average grain size is first increased and afterwards decreased. The ceramics with x = 0.005 exhibit a good piezoelectric behavior of d 33 ~ 464 pC/N and k p ~ 0.44 after three month's aging, which indicates the BCZT -x KNNLST ceramics could be promising for lead-free practical applications.

Partially Aligned Piezoelectric Nanofibers by Sol-Gel Electrospining Process

2005 ◽  
Author(s):  
Yong Shi ◽  
Shiyou Xu ◽  
Sang-Gook Kim
Keyword(s):  
Lead Zirconate Titanate ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Average Diameter ◽  
Lead Zirconate ◽  
Electrospinning Process ◽  
X Ray Diffraction ◽  
Micro Fabrication ◽  
X Ray ◽  
Pure Perovskite Phase

This paper reports the fabrication of partially aligned Lead Zirconate Titanate (PZT) nanofibers with an average diameter of 150 nm by Sol-Gel Electrospinning process. Both randomly distributed and uniaxially aligned PZT fibers were obtained from the sol-gel PZT solution with viscosity modified by polyvinyl pyrrolidone (PVP). The diameters of the nano fibers can be further reduced or controlled for different applications. SEM, TEM and x-ray diffraction (XRD) are used to characterize the nano-fibers and their crystal structures. XRD confirmed that pure perovskite phase was formed after the as-spun fibers being annealed at about 650°C. Different approaches have been explored to fabricate the uniaxially-aligned PZT nano-fibers. Microelectromechanical (MEMS) based micro-fabrication technologies are used to assist the development of the nano-fibers in designing the test samples, depositing and patterning the electrodes, and also testing the performance of the nano fibers.

scholarly journals Synthesis, Giant Dielectric, and Pyroelectric Response of [001]-Oriented Pr3+ Doped Pb(Mg1/3Nb2/3)O3-PbTiO3 Ferroelectric Nano-Films Grown on Si Substrates

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2392 ◽  
Author(s):  
Changlong Cai ◽  
Deqiang Zhang ◽  
Weiguo Liu ◽  
Jun Wang ◽  
Shun Zhou ◽  
...  
Keyword(s):  
Thin Films ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Pyroelectric Coefficient ◽  
X Ray Diffraction ◽  
Si Substrates ◽  
A Value ◽  
Giant Dielectric ◽  
Current Densities ◽  
Pyroelectric Response

The [001]-oriented Pr3+ doped Pb(Mg1/3Nb2/3)O3-0.30PbTiO3 (Pr-PMN-PT) thin films with a composition near the morphotropic phase boundary (MPB) were synthesized by a sol–gel method. The crystal structure was characterized using X-ray diffraction. It was found that a single perovskite phase was achieved in Pr-PMN-PT thin films annealed at 650 °C for 3 min. The dielectric constant (εr) value was 2400 in 2.5% Pr-PMN-PT thin films at room temperature, 110% higher than that of pure PMN-PT samples. Through 2.5% Pr3+ doping, remanent polarization (Pr) and coercive field (Ec) values increased from 11.5 μC/cm2 and 35 kV/cm to 17.3 μC/cm2 and 63.5 kV/cm, respectively, in PMN-PT thin films. The leakage current densities of pure and 2.5% Pr-PMN-PT thin films were on the order of 1.24 × 10−4 A/cm2 and 5.8 × 10−5 A/cm2, respectively, at 100 kV/cm. A high pyroelectric coefficient (py) with a value of 167 μC/m2K was obtained in 2.5% Pr-PMN-PT thin films on Si substrate, which makes this material suitable for application in infrared detectors.

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