Effect of Sintering Temperature on Structure and Dielectric Properties of Lead Free K0.5Na0.5NbO3 Prepared via Hot Isostatic Pressing

2017 ◽  
Vol 888 ◽  
pp. 42-46 ◽  
Author(s):  
Fatin Khairah Bahanurdin ◽  
Julie Juliewatty Mohamed ◽  
Zainal Arifin Ahmad
Keyword(s):  
Grain Size ◽  
Dielectric Properties ◽  
Room Temperature ◽  
Sintering Temperature ◽  
Hot Isostatic Pressing ◽  
Solid State Reaction Method ◽  
Lead Free ◽  
Tangent Loss ◽  
Isostatic Pressing ◽  
Tan Δ

In this research, alkaline niobate known as K0.5Na0.5NbO3 (KNN) lead-free piezoelectric ceramic was synthesis by solid state reaction method which pressing at different sintering temperatures (1000 °C and 1080 °C) prepared via hot isostatic pressing (HIP)). The effect of sintering temperature on structure and dielectric properties was studied. The optimum sintering temperature (at 1080 °C for 30 minutes) using hot isostatic pressing (HIP) was successfully increase the density, enlarge the particle grain size in the range of 0.3 µm – 2.5 µm and improves the dielectric properties of K0.5Na0.5NbO3 ceramics. The larger grain size and higher density ceramics body will contribute the good dielectric properties. At room temperature, the excellent relative permittivity and tangent loss recorded at 1 MHz (ɛr = 5517.35 and tan δ = 0.954), respectively for KNN1080HIP sample. The KNN1080HIP sample is also exhibits highest relative density which is 4.485 g/cm3. The ɛr depends upon density and in this work, the density increase as the sintering temperature increase, which resulting the corresponding ɛr value also increases.

scholarly journals Dielectric characterization of the system Sr1-xGdxTi1-xCoxO3 (x = 0.10) using impedance spectroscopy

2010 ◽  
Vol 7 (2) ◽  
pp. 499-504
Author(s):  
H. S. Tewari ◽  
P. K. Sakharkar
Keyword(s):  
Dielectric Properties ◽  
Impedance Spectroscopy ◽  
Room Temperature ◽  
Sintering Temperature ◽  
Solid State Reaction Method ◽  
Electrical Behavior ◽  
Cooling Rates ◽  
Impedance Analyzer ◽  
Dielectric Characterization

The structure of ceramic grain boundaries, boundary composition, the boundary charge and associated space charge controls the dielectric and electrical behavior of ceramics. Various methods were researched and applied to increase the dielectric constant by formation of insulating layers between semi-conducting grains. In this communication, we are reporting the effect of cooling rates from sintering temperature to room temperature on dielectric properties of the resulting ceramics in the system, Sr1-xGdxTi1-xCoxO3 with x = 0.10. All the samples in this system were prepared by conventional high temperature solid state reaction method. The samples were cooled at different cooling rates from sintering temperature to room temperature. The capacitance and dielectric loss were measured as a function of frequency and temperature using HP 4192A LF impedance analyzer. The samples cooled from different cooling rates from sintering temperature show interesting dielectric properties due to formation of insulating layers between grains. The impedance spectroscopy is used successfully in explaining the dielectric properties of these materials.

scholarly journals Study of Sintering Temperature on Dielectric Properties of CaCu3Ti4O12 Materials Prepared by Sol-Gel Method

2020 ◽  
Vol 32 (12) ◽  
pp. 3109-3112
Author(s):  
W. Sue-Aok ◽  
J. Khemprasit
Keyword(s):  
Dielectric Properties ◽  
Room Temperature ◽  
Sintering Temperature ◽  
Sol Gel ◽  
Cross Linking ◽  
Impedance Analyzer ◽  
Sol Gel Process ◽  
Ft Ir ◽  
Ccto Powder ◽  
Tan Δ

CaCu3Ti4O12 (CCTO) powder was prepared by sol-gel process using acetic acid as a solvent and also as cross-linking agent by varying the sintering temperature (1000-1150 ºC) for 3 h. The dried gels were characterized by TG-DTA and FT-IR techniques. The sintered samples were characterized by XRD, SEM techniques and impedance analyzer for dielectric properties measurement. The sample showed the perovskite structure with small amounts of TiO2 and CuO phases. The best dielectric properties (εr = 1.38 × 104 and tan δ = 0.13 at 10 kHz and room temperature) were observed in the CCTO pellets calcined at 800 ºC for 3 h and sintered at 1100 ºC for 3 h.

Effect of Sintering Temperature on Microstructure and Electrical Properties of (Mn, Nb)-Doped BZT-BCT Ceramics

2013 ◽  
Vol 820 ◽  
pp. 59-62 ◽  
Author(s):  
Cheng Zhang ◽  
Qi Bin Liu ◽  
Xiao Qin Huang
Keyword(s):  
Dielectric Constant ◽  
Grain Size ◽  
Dielectric Properties ◽  
Electrical Properties ◽  
Piezoelectric Coefficient ◽  
Sintering Temperature ◽  
Lead Free ◽  
Reaction Route ◽  
Conventional Solid State Reaction ◽  
Solid State Reaction Route

To obtain lead-free 0.5Ba (Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 ceramics with excellent microstructure and electrical properties, BZT-BCT ceramics doping Mn4+ and Nb5+ was synthesized follow a conventional solid state reaction route. By means of SEM, XRD, quasi-static d33 meter, the influence of sintering temperature on microstructure, piezoelectric and dielectric properties of BZT-BCT-Mn-Nb ceramics was discussed. The results show that grain size and the dielectric loss of BZT-BCT-Mn-Nb ceramics increase as raising the sintering temperature. When BZT-BCT-Mn-Nb ceramics is sintered at 1380°C, the optimum piezoelectric coefficient and dielectric constant are 264pC/N and 4142, respectively.

Influence of Various Tin Ion Doped Amount on the Dielectric Properties of BMNS Ceramics

2013 ◽  
Vol 380-384 ◽  
pp. 4258-4261
Author(s):  
Xin You Huang ◽  
Mu Sheng Huang ◽  
Chun Hua Gao ◽  
Yuan Zuo
Keyword(s):  
Dielectric Constant ◽  
Grain Size ◽  
Dielectric Properties ◽  
Sintering Temperature ◽  
Pyrochlore Phase ◽  
Solid State Reaction Method ◽  
Second Phase ◽  
Doping Amount ◽  
Reaction Method ◽  
Ion Doping

Bi2(Mg1/3Nb2/3-xSnx)2O7(BMNS)(x=0.1,x=0.15,x=0.2,x=0.25 mol) ceramics was prepared by traditional solid-state reaction method and the influence of tin ion doped amount on the dielectric properties and structure of BMNS ceramics were investigated. The results show that all of the doped samples keep a single monoclinic pyrochlore phase and there is no second phase observed. The grain size of ceramics gradually increases, the dielectric constant decreases first and then increases, the dielectric loss increases first and then decreases and the density reduces with the increase of tin ion doped amount. The density of ceramics increases first then decreases with the increase of sintering temperature. The BMNS ceramics sintered at 980 °C with 0.25 mol tin ion doping amount has a biggest density and the best properties,whose εris 155(1MHz),tanδ is 0.0011(1MHz), the bulk density is 7.62 g/cm3.

scholarly journals Evolution of the Microstructure and Mechanical Properties of a Ti35Nb2Sn Alloy Post-Processed by Hot Isostatic Pressing for Biomedical Applications

Metals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1027
Author(s):  
Joan Lario ◽  
Ángel Vicente ◽  
Vicente Amigó
Keyword(s):  
Powder Metallurgy ◽  
Mechanical Strength ◽  
Room Temperature ◽  
Hot Isostatic Pressing ◽  
Phase Changes ◽  
Post Processing ◽  
Isostatic Pressing ◽  
Porosity Reduction ◽  
Processing Step ◽  
Hip Process

The HIP post-processing step is required for developing next generation of advanced powder metallurgy titanium alloys for orthopedic and dental applications. The influence of the hot isostatic pressing (HIP) post-processing step on structural and phase changes, porosity healing, and mechanical strength in a powder metallurgy Ti35Nb2Sn alloy was studied. Powders were pressed at room temperature at 750 MPa, and then sintered at 1350 °C in a vacuum for 3 h. The standard HIP process at 1200 °C and 150 MPa for 3 h was performed to study its effect on a Ti35Nb2Sn powder metallurgy alloy. The influence of the HIP process and cold rate on the density, microstructure, quantity of interstitial elements, mechanical strength, and Young’s modulus was investigated. HIP post-processing for 2 h at 1200 °C and 150 MPa led to greater porosity reduction and a marked retention of the β phase at room temperature. The slow cooling rate during the HIP process affected phase stability, with a large amount of α”-phase precipitate, which decreased the titanium alloy’s yield strength.

scholarly journals Structure-Property Correlation in Ir Transparent Zinc Sulphide (Zns) Ceramics Under Chemical Vapour Deposited & Hot Iso-Statically Pressed Conditions

2019 ◽  
Vol 3 (2) ◽  
Keyword(s):  
Grain Size ◽  
Hot Isostatic Pressing ◽  
Chemical Vapour ◽  
Complex Impedance ◽  
Ac Impedance ◽  
Spectroscopic Studies ◽  
Structure Property ◽  
Frequency Range ◽  
Equivalent Circuit Analysis ◽  
Isostatic Pressing

IR Transparent ZnS ceramics processed through chemical vapour deposition were subjected to Hot Isostatic pressing and the samples in both the conditions were characterized by XRD, microstructure and high temperature impedance spectroscopic studies for the dielectric and electrical properties. Both the samples have shown cubic sphalerite phase with enhanced orientation along (111) plane as a result of hot isostatic pressing as revealed by XRD.HIP treatment to ZnS facilitated the enhancement of the homogeneity of microstructure and enhancement in the grain size from 10μm to 50μm. The electrical behavior of both the samples was investigated by AC impedance spectroscopy in the frequency range 1Hz to 1MHz from RT to 500°C in dry air. HIP has resulted in a significant increase in the dielectric constant, which can be attributed to the increase in homogeneity and the grain size. Further, the complex impedance plots exhibited two impedance semicircles identified in the frequency range is explained by the grain and grain boundary effects. An equivalent-circuit analysis of AC impedance spectra based on the brick-layer model was performed. Activation energies obtained from the conductivity plots indicates an Arrhenius type thermally activated process.

Dielectric Properties and Raman Spectroscopy in Ca-Substituted Na0.5Bi0.5TiO3 Ferroelectric Ceramics

2011 ◽  
Vol 324 ◽  
pp. 298-301 ◽  
Author(s):  
Roy Jean Roukos ◽  
Olivier Bidault ◽  
Julien Pansiot ◽  
Ludivine Minier ◽  
Lucien Saviot
Keyword(s):  
Raman Spectroscopy ◽  
Dielectric Properties ◽  
Room Temperature ◽  
Rhombohedral Phase ◽  
Xrd Analysis ◽  
Solid State Reaction Method ◽  
Ferroelectric Ceramics ◽  
Dielectric Measurements ◽  
X Ray Diffraction ◽  
X Ray

Lead free Na0.5Bi0.5TiO3 (NBT) and (Na0.5Bi0.5TiO3)1-x(CaTiO3)x (NBT-CT) piezoelectric ceramics with the perovskite structure were studied. The NBT and NBT-CT samples were synthesized using a solid-state reaction method and characterized with X-ray diffraction (XRD), Raman spectroscopy and dielectric measurements for several compositions (x = 0, 0.07, 0.15) at room temperature. The XRD analysis showed a stabilization of a rhombohedral phase at a low concentration of Ca (0 < x <0.15), whereas Raman spectra reveal a strong modification for the sample with x = 0.15. The dielectric properties of these ceramics were studied by measuring impedance in the 79-451K temperature range for unpoled and field cooling with an electric field (FC) conditions.

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