Effect of La2O3 Additions on Microstructure, Morphology and Pressure Sensing Behaviour of PZT Based Ceramics Sintered in Al2O3 Environment

2010 ◽  
Vol 173 ◽  
pp. 96-101
Author(s):  
Mohammad Hafizuddin Haji Jumali ◽  
Ying Ying Tio ◽  
Ramli Norhashimah ◽  
Mat Salleh Muhammad ◽  
Muhammad Yahaya
Keyword(s):  
Structural Investigation ◽  
Solid State Reaction Method ◽  
Conventional Solid State Reaction ◽  
Pressure Sensing ◽  
Novel Approach ◽  
Tetragonal Crystal ◽  
Tetragonal Crystal Structure ◽  
Average Grain Size ◽  
Custom Made ◽  
Microstructure Morphology

Effect of La2O3 addition on microstructure, morphology and pressure sensing behaviour of (Pb1-x, Lax)(Zr0.52, Ti0.48)O3 based ceramics was studied in three different compositions of La2O3, namely x = 0.10, 0.12 and 0.15. The samples were prepared through a conventional solid-state reaction method using high purity metal oxides powders. In order to control the PbO losses due to high sintering temperature, a novel approach was explored whereby the samples were sintered in Al2O3 environment. Structural investigation using XRD revealed that all samples exhibited a tetragonal crystal structure. However the c/a ratios exhibited a decreasing trend as the La2O3 content increased, indicating that (Pb1-x, Lax)(Zr0.52, Ti0.48)O3 crystals gradually evolved towards pseudocubic structure. SEM micrographs showed that in all samples the grains have uniform pebble stone morphology. The average grain size reduced from ~ 4.5 µm to ~ 3.0 µm with the increment of La¬2O3 content. The performance of pressure sensing behaviour which was investigated using custom-made pressure chamber showed that sample with composition of x = 0.10 exhibited the best piezoelectric properties with high pressure sensitivity, good stability and repeatability.

scholarly journals Structure, Dielectric and Multiferroic Properties of Bi0.85Nd0.15Fe0.98Zr0.02O3 in Ba and Ti Co-Doping

2021 ◽  
Author(s):  
Lizhu Zeng ◽  
Yuming Lu ◽  
Lujia Zhang ◽  
Xin Gong ◽  
Jianfeng Tang ◽  
...  
Keyword(s):  
Room Temperature ◽  
Oxygen Vacancies ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
Conventional Solid State Reaction ◽  
Structure Transition ◽  
X Ray ◽  
Co Doping ◽  
Average Grain Size ◽  
Rhombohedral Perovskite Structure

Abstract Multiferroic (1- x)Bi0.85Nd0.15Fe0.98Zr0.02O3- xBaTiO3 (x = 0, 0.275, 0.3, 0.325, 0.35, 0.375, 0.4) ceramics were synthesized by the conventional solid state reaction method. X-ray diffraction studies confirm the phase transition from rhombohedral perovskite structure to pseudocubic structure with the introduction of BaTiO3. The results of the refinement indicate the BaTiO3 is successfully doped into the crystal lattice. The microstructure analysis shows that the average grain size increases with the introduction of BaTiO3. An increase in remanant polarization has been achieved at room temperature as the BaTiO3 concentration increasing. A greatly reduced leakage current density of about two orders of magnitude is observed in x = 0.375 (J = 2.4×10− 7 A/cm2) ceramic. The dielectric properties have been enhanced by the addition of BaTiO3, which is attributed to the reduction in Fe2+ ions and oxygen vacancies. Due to the grain effect and structure transition caused by the doping of BaTiO3, the magnetization reveals a slight decrease while the coercive field for x = 0.325 (Hc = 1785.8 Oe) increases to 6.4 times of the undoped ceramic.

Investigation of Structural and Dielectric Properties of Polycrystalline PbMg1∕3 Ti1∕3W1∕3O3 Tungsten Perovskite

SPIN ◽  
2020 ◽  
Vol 10 (03) ◽  
pp. 2050021
Author(s):  
P. Ganga Raju Achary ◽  
R. N. P. Choudhary ◽  
S. K. Parida
Keyword(s):  
Activation Energy ◽  
Conduction Mechanism ◽  
Complex Impedance ◽  
Interfacial Polarization ◽  
Average Crystallite Size ◽  
Solid State Reaction Method ◽  
Tetragonal Crystal ◽  
Average Grain Size ◽  
Temperature Ranges ◽  
Lead Magnesium

Lead magnesium tungsten titanate PbMg[Formula: see text] Ti[Formula: see text]W[Formula: see text]O3 was prepared by adopting a high-temperature solid-state reaction method. The sample has tetragonal crystal structure having average crystallite size 45.1325[Formula: see text]nm calculated using Scherer’s relation and the average grain size is about 40[Formula: see text]nm from Scanning Electron Microscope (SEM) measurement. Measurements of dielectric permittivity ([Formula: see text]) and loss ([Formula: see text]) have been investigated, both as a function of frequency (1[Formula: see text]kHz to 5[Formula: see text]MHz) and temperature (25–[Formula: see text]C) and the results showed the presence of interfacial polarization of the material. The dielectric spectra with frequency and temperature suggest that the prepared sample is semiconducting in nature following the NTCR behavior. The complex impedance results showed the contribution of grain and grain boundaries in the conduction mechanism. The activation energies were determined from the ac conductivity data in the temperature ranges of 200–[Formula: see text]C and 360–[Formula: see text]C. It has been observed that with the rise of frequency and temperature, the activation energy increases in the sample. The greater value of the activation energy always supports the conduction mechanism due to hopping of the charge carriers. The semicircular arcs of Cole–Cole plots confirm that the sample is semiconducting in nature which supports our dielectric results.

Dielectric Properties of CaCu3Ti4O12/Al2O3 Composites

2017 ◽  
Vol 888 ◽  
pp. 12-16
Author(s):  
Mohamad Johari Abu ◽  
Rosyaini Afindi Zaman ◽  
Mohd Fariz Ab Rahman ◽  
Mohsen Ahmadipour ◽  
Julie Juliewatty Mohamed ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Solid State Reaction Method ◽  
Boundary Resistance ◽  
Frequency Range ◽  
Conventional Solid State Reaction ◽  
Reaction Method ◽  
X Ray ◽  
Average Grain Size ◽  
Tan Δ ◽  
Composite Samples

In this work, (1-x)CaCu3Ti4O12/xAl2O3 (x = 0, 0.01, 0.03, 0.05 and 0.1) composite samples were prepared by the conventional solid-state reaction method. The dielectric properties of the samples were investigated at frequency range of 20 – 106 Hz. X-ray diffractogram results show that the samples with Al2O3 sintered at 1040 °C/10 h are mixed phase and consist of CaCu3Ti4O12, CuAl2O4, TiO2 and Al2O3. The average grain size of the samples increased greatly for x = 0.01, then abruptly depressed for x ≥ 0.03. Al2O3-added (x = 0.01) has been shown to increase the dielectric permittivity (ε’) up to ~5000 over frequency range of 102 – 105 Hz, while retaining the dielectric loss (tan δ ~ 0.15) at 1 kHz. With further increase of Al2O3 content, the ε’ and tan δ values of the samples are decreased monotonically in all frequency ranges. The improvement of dielectric properties in the composite sample was attributed to the enhanced grain boundary resistance.

scholarly journals Structural, Morphological and Magnetic Properties of Nd and Co co-doped BiFeO3 Ceramics at Room temperature

2017 ◽  
Vol 41 (1) ◽  
pp. 85-93 ◽  
Author(s):  
Tamanna Mariam ◽  
Shamima Choudhury
Keyword(s):  
Grain Size ◽  
Magnetic Properties ◽  
Room Temperature ◽  
Hysteresis Loops ◽  
Magnetic Behavior ◽  
Solid State Reaction Method ◽  
Conventional Solid State Reaction ◽  
Average Grain Size ◽  
Co Doped ◽  
Simultaneous Substitution

Synthesis and characterization of BiFeO3 samples, co-doped with rare earth Nd and Co in place of Bi and Fe respectively were investigated at room temperature (RT). The formula of the four samples are Co-doped BiFe1–xCoxO3 (x = 0.05-0.10) and Nd and Co co-substituted Bi0.95Nd0.05Fe0.95Co0.05O3 and Bi0.90Nd0.10Fe0.90Co0.10O3. These ceramic samples were synthesized by conventional solid state reaction method. The X-ray diffraction patterns clearly reveal that the secondary impurity phases were eliminated significantly due to the simultaneous substitution of Nd and Co in place of Bi and Fe respectively of BiFeO3 ceramics. The surface morphology of the synthesized samples was found to improve due to the simultaneous substitution of Nd and Co in place of Bi and Fe in BiFeO3. The average grain size of the first sample with 5% doping of Co in place of Fe was 1.5?m. In the second sample with 10% Co doping in place of Fe, the average grain size became 1.25 ?m. In presence of 5% Nd in place of Bi as well as with 5% doping of Co in place of Fe , grain size reduced to 0.75?m. The sample with 10% doping of Nd and Co in place of Bi and Fe respectively, average grain size decreased to 0.5?m. The EDX spectroscpoy ensured the presence of Bi, Nd, Fe, Co and O in these samples and their percentage of mass and atoms. Magnetic properties of the samples were also investigated at room temperature by measuring magnetization versus magnetic field (M-H) hysteresis loops. The wider loop clearly demonstrates the significant improvement of the magnetic behavior in 10% Nd and Co doped Bi0.90Nd0.10Fe0.90Co0.10O3 sample. The enhanced magnetic properties might be attributed to the substitution induced suppression of spiral spin structure of BiFeO3. The outcome of this investigation suggests the potentiality of the simultaneous doping of Nd and Co in BiFeO3 ceramics to improve their structural, morphological and magnetic characteristics.Journal of Bangladesh Academy of Sciences, Vol. 41, No. 1, 85-93, 2017

Effect of CeO2 Nanoparticle on the Structural and Electrical Properties of BSCCO-2223 High Temperature Superconductor

2020 ◽  
Vol 307 ◽  
pp. 104-109
Author(s):  
E.S. Nurbaisyatul ◽  
Hashim Azhan ◽  
Azman Kasim ◽  
Norazila Ibrahim
Keyword(s):  
High Temperature Superconductor ◽  
Xrd Analysis ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
Critical Transition Temperature ◽  
X Ray ◽  
Tetragonal Crystal ◽  
Tetragonal Crystal Structure ◽  
Structural And Electrical Properties ◽  
Oxide Nanoparticle

A study of the effects of Cerium oxide nanoparticle doped with BSCCO-2223 on the microstructure and superconducting properties was carried out. All samples were synthesized using solid state reaction method. Ce concentration is varied from x = 0.0 up to 0.1 in a general stoichiometry of Bi1.6Pb0.4Sr2Ca1-xCexCu3Oy. The samples were characterized structurally and electrically by X-Ray Diffraction (XRD) and four-point probe method respectively. XRD analysis shows that both (Bi,Pb)-2212 and (Bi,Pb)-2223 phases coexist in the samples having tetragonal crystal structure but changed to orthorhombic when x=0.10. The values of critical transition temperature, TC and critical current density, JC of the samples decreased with the increase in Ce concentration. The possible reasons for the observed degradation in superconducting and structural properties of Bi-2223 due to Ce nanoparticles addition were discussed.

Transformation of Structure, Magnetic Properties and Microwave Absorption Capability in Nd-Doped Strontium Hexaferrite

2020 ◽  
Vol 855 ◽  
pp. 255-260
Author(s):  
Mukhtar Effendi ◽  
Efi Solihah ◽  
Candra Kurniawan ◽  
Wahyu Tri Cahyanto ◽  
Wahyu Widanarto
Keyword(s):  
Magnetic Properties ◽  
Microwave Absorption ◽  
Solid State Reaction Method ◽  
Strontium Hexaferrite ◽  
Basic Material ◽  
X Ray Diffraction ◽  
Cell Parameters ◽  
Tetragonal Crystal ◽  
Capability Analysis ◽  
Natural Iron

The synthesize of Nd3+-strontium hexaferrite magnetic material by the solid-state reaction method has been successfully carried out. This study aims to determine the effect of Nd3+ on the structure, magnetic properties, and microwave absorption capability of the material. Preparation of (1-x)SrO:xNd2O3:6Fe2O3 where x = 0, 10, 20, and 30 mol% using basic material in the form of SrCO3 powder, Nd2O3 powder and Fe3O4 from natural iron sand. The characterization includes the X-Ray Diffraction (XRD) examination to determine the crystal structure, the Scanning Electron Microscope (SEM) for exploring the surface morphology, Vibrating Sample Magnetometer (VSM) for the magnetic properties investigation of material, and Vector Network Analyzer (VNA) for microwave absorption capability analysis. The XRD results show that the addition of Nd3+ doping increases the number of SrNdFeO4 phases. The phase has a tetragonal crystal system that has cell parameters a = b = 3.846 Å, and c = 12.594 Å. The magnetic properties of the material showed that the addition of Nd3+ decreased the saturation and remanence magnetization values, whereas the value of the coercivity field increased. Meanwhile, the best microwave absorption occurs in samples with the addition of Nd3+ as much as 0.3 mol, which results in a reflection loss value of -18.9 dB with a frequency bandwidth of 3.9 GHz.

scholarly journals Drastic improvement of Curie temperature by chemical pressure in N-type diluted magnetic semiconductor Ba(Zn,Co)$$_{2}$$As$$_{2}$$

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Licheng Fu ◽  
Yilun Gu ◽  
Guoxiang Zhi ◽  
Haojie Zhang ◽  
Rufei Zhang ◽  
...  
Keyword(s):  
Unit Cell Volume ◽  
Diluted Magnetic Semiconductor ◽  
Magnetic Semiconductor ◽  
Vital Role ◽  
Ferromagnetic Transition ◽  
Chemical Pressure ◽  
Tetragonal Crystal ◽  
Tetragonal Crystal Structure ◽  
Diluted Magnetic ◽  
Ferromagnetic Ordering

AbstractWe report the effect of chemical pressure on the ferromagnetic ordering of the recently reported n-type diluted magnetic semiconductor Ba(Zn$$_{1-x}$$ 1 - x Co$$_{x}$$ x )$$_{2}$$ 2 As$$_{2}$$ 2 which has a maximum $$T_C$$ T C $$\sim$$ ∼ 45 K. Doping Sb into As-site and Sr into Ba-site induces negative and positive chemical pressure, respectively. While conserving the tetragonal crystal structure and n-type carriers, the unit cell volume shrink by $$\sim$$ ∼ 0.3$$\%$$ % with 15$$\%$$ % Sr doping, but drastically increase the ferromagnetic transition temperature by 18$$\%$$ % to 53 K. Our experiment unequivocally demonstrate that the parameters of Zn(Co)As$$_{4}$$ 4 tetrahedra play a vital role in the formation of ferromagnetic ordering in the Ba(Zn,Co)$$_{2}$$ 2 As$$_{2}$$ 2 DMS.

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.

Study on Dielectric and Ferroelectric Properties of Gd-Doped Sr2Bi4Ti5O18 Ceramics

2011 ◽  
Vol 328-330 ◽  
pp. 1131-1134
Author(s):  
Qian Chen ◽  
Zhi Jun Xu ◽  
Rui Qing Chu ◽  
Yong Liu ◽  
Ming Li Chen ◽  
...  
Keyword(s):  
Piezoelectric Properties ◽  
Ferroelectric Properties ◽  
Solid State Reaction Method ◽  
Lead Free ◽  
Structural Ceramics ◽  
Conventional Solid State Reaction ◽  
Reaction Method ◽  
Maximum Value ◽  
Pure Bismuth ◽  
Ferroelectric And Piezoelectric Properties

Lead-free piezoelectric ceramics Sr2Bi4-xGdxTi5O18 were prepared by conventional solid-state reaction method. Pure bismuth layered structural ceramics with uniform gain size were obtained in all samples. The effect of Gd-doping on the dielectric, ferroelectric and piezoelectric properties of Sr2Bi4Ti5O18 ceramics were also investigated. It was found that that Gd3+ dopant gradually decreased the Curie temperature (Tc) with the lower dielectric loss (tand) of SBTi ceramics. In addition, Gd-doping with appropriate content improved the ferroelectric and piezoelectric properties of the SBTi ceramics. The piezoelectric constant (d33) of the Sr2Bi3.9Gd0.1Ti5O18 ceramic reached the maximum value, which is 22 pC/N. The results showed that the Sr2Bi4-xGdxTi5O18 ceramic was a promising lead-free piezoelectric material.

scholarly journals Characterization of tin dioxide nanoparticles synthesized by oxidation

Cerâmica ◽  
2015 ◽  
Vol 61 (359) ◽  
pp. 328-333 ◽  
Author(s):  
R. C. Abruzzi ◽  
B. A. Dedavid ◽  
M. J. R. Pires
Keyword(s):  
Gas Sensors ◽  
Tin Dioxide ◽  
X Ray Diffraction ◽  
X Ray ◽  
Synthesis Conditions ◽  
Tetragonal Crystal ◽  
Tetragonal Crystal Structure ◽  
Activation Efficiency ◽  
Complementary Techniques

AbstractTin dioxide (SnO2) is a promising material with great potential for applications such as gas sensors and catalysts. Nanostructures of this oxide exhibit greater activation efficiency given their larger effective surface. The present study presents results of the synthesis and characterization of tin dioxide under different conditions via oxidation of solid tin with nitric oxide. SnO2powder was characterized primarily by X-ray diffraction and scanning electron microscopy, as well as complementary techniques such as energy-dispersive X-ray spectroscopy, dynamic light scattering and Fourier transform infrared spectroscopy. The results indicated that the established synthesis conditions were suitable for obtaining rutile tin dioxide nanoparticles with a tetragonal crystal structure.

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