Effect of Lanthanum Substitution on the Structural, dielectric, Ferroelectric and Piezoelectric Properties of Mechanically Activated PZt Electroceramics

2016 ◽  
Vol 66 (4) ◽  
pp. 360 ◽  
Author(s):  
Ajeet Kumar ◽  
V.V. Bhanu Prasad ◽  
K.C. James Raju ◽  
Rajdeep Sarkar ◽  
P. Ghosal ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Electromechanical Coupling ◽  
Perovskite Phase ◽  
Average Particle Size ◽  
Field Measurements ◽  
Electromechanical Coupling Factor ◽  
High Energy ◽  
Cold Isostatic Pressing ◽  
Average Particle ◽  
Morphological Studies

Different compositions of (Pb1-xLax) (Zr0.60Ti0.40)O3 (abbreviated as PLZT x/60/40; x=0, 0.07, 0.08 and 0.10) ceramics were prepared by a combinatorial approach by high energy mechano-chemical ball milling and cold isostatic pressing (CIP). X-ray diffraction patterns and transmission as well as scanning electron microscope were used for the micro-structural and morphological studies. The average particle size of PLZT milled powders was measured from the TEM images and was found to be in the nm range.XRD patterns of the sintered PLZT x/60/40 ceramics confirm the perovskite phase formation after heat treatment. SEM of sintered PLZT x/60/40 ceramics show a close packed dense structure. PLZT 8/60/40 ceramics show the fine grains (~1.3 µm) with density ~97 per cent. Dielectric constant and loss were measured as a function of temperature. PLZT 8/60/40 ceramics shows the highest value of room temperature dielectric constant ~2480 at 1 kHz. Ferroelectric studies were done with the help of polarisation (P-E) and strain (S-E) vs. electric field measurements. PLZT 8/60/40 ceramics shows the maximum value of remnant polarisation (~36 µC/cm2) and strain (~0.27 per cent), respectively. PLZT x/60/40 ceramic samples were poled at optimized poling conditions. The measured values of piezoelectric charge coefficient (d33) and electromechanical coupling factor (kp) of PLZT 8/60/40 ceramics were found to be, ~690 pC/N and ~71 per cent, respectively.

Comparison of Milling Techniques to Figure of Merit of 0.98PZT-0.02BYF Piezoelectric Ceramic Energy Harvester

2016 ◽  
Vol 690 ◽  
pp. 218-223
Author(s):  
Piyalak Ngernchuklin ◽  
Arjin Boonruang ◽  
Saengdoen Daungdaw ◽  
Nestchanok Yongpraderm
Keyword(s):  
Ball Milling ◽  
Figure Of Merit ◽  
Perovskite Phase ◽  
Average Particle Size ◽  
Pyrochlore Phase ◽  
Electrical Energy ◽  
High Energy ◽  
Average Particle ◽  
K Value ◽  
Pure Perovskite Phase

Nowadays, the concept of harvesting energy from the environment, for example, thermal, wind, sun, vibration and human activities is much of interest. PZT is one of the materials which show an ability to harness vibration energy and then change to electrical energy. Therefore, the PZT (Pb(Zr0.53Ti0.47)O3) doped with 0.02 mol% BYF (Bi(Y0.7Fe0.3)O3) piezoelectric ceramics has been studied to improve the figure of merit (d33*g33). The PZT and BYF powder systems were prepared by solid state reaction with calcination temperature of 800 and 850 °C for 2 h, respectively. XRD results showed that both powders exhibited pure perovskite phase for PZT and single phase of BYF without pyrochlore phase. Then, the two calcined powders (PZT and BYF) were mixed according to the composition of 0.02 mol% BYF doped PZT by two different milling techniques called conventional ball-milling (CBM) and high energy ball-milling (HBM) for 10 h. The result showed that average particle size obtain from HBM was 1 µm which was smaller than from CBM shown up to a few microns in bimodal mode. The PZT-BYF-HBM ceramics showed higher physical and electrical properties but lower K value. Thus promoting to higher g33 which was equal to 36.89 * 10-3(Vm/N) and FOM was 11,632*10-15(m2/N), while PZT-BYF-CBM had g33 of 26.86* 10-3(Vm/N) and FOM at 8,016*10-15(m2/N), respectively.

scholarly journals Green synthesis: Proposed mechanism and factors influencing the synthesis of platinum nanoparticles

2020 ◽  
Vol 9 (1) ◽  
pp. 386-398 ◽  
Author(s):  
Mahmood S. Jameel ◽  
Azlan Abdul Aziz ◽  
Mohammed Ali Dheyab
Keyword(s):  
Green Synthesis ◽  
Reaction Temperature ◽  
Platinum Nanoparticles ◽  
Energy Requirement ◽  
Average Particle Size ◽  
High Energy ◽  
Energy Utilization ◽  
Critical Parameters ◽  
Synthesis Process ◽  
Average Particle

AbstractPlatinum nanoparticles (Pt NPs) have attracted interest in catalysis and biomedical applications due to their unique structural, optical, and catalytic properties. However, the conventional synthesis of Pt NPs using the chemical and physical methods is constrained by the use of harmful and costly chemicals, intricate preparation requirement, and high energy utilization. Hence, this review emphasizes on the green synthesis of Pt NPs using plant extracts as an alternative approach due to its simplicity, convenience, inexpensiveness, easy scalability, low energy requirement, environmental friendliness, and minimum usage of hazardous materials and maximized efficiency of the synthesis process. The underlying complex processes that cover the green synthesis (biosynthesis) of Pt NPs were reviewed. This review affirms the effects of different critical parameters (pH, reaction temperature, reaction time, and biomass dosage) on the size and shape of the synthesized Pt NPs. For instance, the average particle size of Pt NPs was reported to decrease with increasing pH, reaction temperature, and concentration of plant extract.

COMPARATIVE STUDY OF DIELECTRIC BEHAVIOR OF Mn0.4Zn0.6Fe2O4 NANOFERRITE BY CITRATE PRECURSOR METHOD

2008 ◽  
Vol 22 (16) ◽  
pp. 2537-2544 ◽  
Author(s):  
PREETI MATHUR ◽  
ATUL THAKUR ◽  
M. SINGH
Keyword(s):  
Particle Size ◽  
Dielectric Constant ◽  
Comparative Study ◽  
Average Particle Size ◽  
Dielectric Behavior ◽  
Average Particle ◽  
Oxidizing Agent ◽  
Precursor Method ◽  
Citrate Precursor ◽  
Citrate Precursor Method

In the present work, comparative study of the dielectric behavior of Mn 0.4 Zn 0.6 Fe 2 O 4 ferrite synthesized with and without H 2 O 2 (hydrogen peroxide) has been presented. The dc resistivity has been improved by the citrate precursor method as compared to the ceramic method, and it is further improved by the addition of H 2 O 2, which acts as a strong oxidizing agent. We have shown by means of X-ray diffraction that the resulting ferrite is made up of nanocrystallites and the average size of these nanocrystallites–calculated by Scherrer's formula–depends on the polarizer. The average particle size was found to be ~70 nm with H 2 O 2 and ~88 nm without H 2 O 2. The particle size is further confirmed by scanning electron microscopy. Both the results are found to be in good agreement. The decrease in dielectric constant and dielectric loss factor by addition of oxidizing agent is justified by inverse proportionality between the resistivity and dielectric constant. Possible mechanisms contributing to these processes have been discussed.

Influence of Excess Bi2O3 and Na2Co3 on Crystal Structure and Microstructure of Bismuth Sodium Titanate Ceramics

2011 ◽  
Vol 474-476 ◽  
pp. 1711-1714 ◽  
Author(s):  
Panadda Sittiketkron ◽  
Arrak Klinbumrung ◽  
Theerachai Bongkarn
Keyword(s):  
Crystal Structure ◽  
Dielectric Properties ◽  
Perovskite Phase ◽  
Average Particle Size ◽  
Sodium Titanate ◽  
Solid State Reaction Method ◽  
Lattice Parameter ◽  
Rhombohedral Structure ◽  
Average Particle ◽  
Average Grain Size

This study investigated the influence of excess Bi2O3 and Na2CO3 on the crystal structure, microstructure and dielectric properties of (Bi0.5Na0.5)TiO3 (BNT) ceramics. The BNT ceramics were synthesized using the solid-state reaction method with various excess Bi2O3 and Na2CO3 levels (0, 1, 2, 3 and 4 mol%). The X-ray characterization revealed that all samples had a rhombohedral structure. A pure perovskite phase was obtained in all samples. The lattice parameter a tended to increase with increased excess Bi2O3 and Na2CO3 content in the calcined powders and sintered ceramics. The average particle size increased while, the average grain size tended to decreased with increased of excess Bi2O3 and Na2CO3 content. The depolarization temperature (Td) and the Curie temperature (Tc) were slightly decreased with the increase of excess Bi2O3 and Na2CO3 content. The dielectric properties were related to the density.

Influence of Poling Conditions on the Characteristics of PZT Ceramics

2011 ◽  
Vol 284-286 ◽  
pp. 1375-1380 ◽  
Author(s):  
Ming Cheng Chure ◽  
Ping Cheng Chen ◽  
Long Wu ◽  
Bing Huei Chen ◽  
King Kung Wu
Keyword(s):  
Dielectric Constant ◽  
Electromechanical Coupling ◽  
Electromechanical Coupling Factor ◽  
Coupling Factor ◽  
Poling Field ◽  
Pzt Ceramics ◽  
Poling Process ◽  
Poling Temperature ◽  
Higher Temperature ◽  
Planar Electromechanical Coupling Factor

In the poling process of PZT ceramics, the poling temperature is a critical condition. When the poling temperature is too low, no matter how high is the poling field and how long is the poling time, the planar electromechanical coupling factor kpis lower. When the poling temperature is higher enough, the kpcan reach to a saturated value with a lower poling field and short poling time. The variation of dielectric constant with the poling conditions is the same as that of planar electromechanical coupling factor. When poling with a low temperature, the dielectric constant after poling is lower than 1400. When poling with higher temperature, no matter how high is the poling field and how long is the poling time, the dielectric constant after poling is higher than 1500.

Characteristics of La0.8Sr0.05Ca0.15CrO3 Interconnect Material for SOFC Synthesized by a Modified Pechini Method, USP, and GNP

2007 ◽  
Vol 124-126 ◽  
pp. 799-802
Author(s):  
Tak Hyoung Lim ◽  
Gil Yong Lee ◽  
Dong Hyun Peck ◽  
Rak Hyun Song ◽  
Dong Ryul Shin
Keyword(s):  
Particle Size ◽  
Perovskite Phase ◽  
Pechini Method ◽  
Average Particle Size ◽  
Spherical Shape ◽  
Average Particle ◽  
Orthorhombic Structure ◽  
Single Perovskite Phase ◽  
Modified Pechini Method ◽  
Interconnect Material

The characteristics of La0.8Sr0.05Ca0.15CrO3 interconnect material synthesized by modified pechini method, USP, and GNP was investigated. The powder synthesized by Pechini method exhibited somewhat aggregated shape. The precursor synthesized by USP had spherical shape and their particle size decreased somewhat after calcining procedure at 1000oC. In the case of GNP, the precursor formed agglomerated particles. The average particle size of powders synthesized by Pechini method, USP, and GNP were 0.4+m, 0.6+m, and below 10nm, respectively. The La0.8Sr0.05Ca0.15CrO3 powder had a single perovskite phase and orthorhombic structure. After sintering at 1400oC and 1500oC, the relative density of samples synthesized by pechini method was approximately 95% and that of samples synthesized by USP was slightly small. However, that of the samples synthesized by GNP was approximately 92%.

scholarly journals The Effects of Curcumin Nanoparticles Incorporated into Collagen-Alginate Scaffold on Wound Healing of Skin Tissue in Trauma Patients

Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4291
Author(s):  
Mohammadmahdi Mobaraki ◽  
Davood Bizari ◽  
Madjid Soltani ◽  
Hadi Khshmohabat ◽  
Kaamran Raahemifar ◽  
...  
Keyword(s):  
Wound Healing ◽  
Healing Process ◽  
Average Particle Size ◽  
L929 Cell ◽  
Skin Tissue ◽  
Wound Healing Process ◽  
Average Particle ◽  
Trauma Patients ◽  
Morphological Studies

Wound healing is a biological process that is mainly crucial for the rehabilitation of injured tissue. The incorporation of curcumin (Cur) into a hydrogel system is used to treat skin wounds in different diseases due to its hydrophobic character. In this study, sodium alginate and collagen, which possess hydrophilic, low toxic, and biocompatible properties, were utilized. Collagen/alginate scaffolds were synthesized, and nanocurcumin was incorporated inside them; their interaction was evaluated by FTIR spectroscopy. Morphological studies investigated structures of the samples studied by FE-SEM. The release profile of curcumin was detected, and the cytotoxic test was determined on the L929 cell line using an MTT assay. Analysis of tissue wound healing was performed by H&E staining. Nanocurcumin was spherical, its average particle size was 45 nm, and the structure of COL/ALG scaffold was visible. The cell viability of samples was recorded in cells after 24 h incubation. Results of in vivo wound healing remarkably showed CUR-COL/ALG scaffold at about 90% (p < 0.001), which is better than that of COL/ALG, 80% (p < 0.001), and the control 73.4% (p < 0.01) groups at 14 days/ The results of the samples’ FTIR indicated that nanocurcumin was well-entrapped into the scaffold, which led to improving the wound-healing process. Our results revealed the potential of nanocurcumin incorporated in COL/ALG scaffolds for the wound healing of skin tissue in trauma patients.

Sign in / Sign up

Export Citation Format

Share Document