Electrical Properties of Fresnoite Ba2TiSi2O8 Using Impedance Spectroscopy

2013 ◽  
Vol 795 ◽  
pp. 640-643 ◽  
Author(s):  
Rozana A.M. Osman ◽  
Mohd Sobri Idris
Keyword(s):  
Activation Energy ◽  
Solid State ◽  
Sintering Temperature ◽  
Second Harmonic ◽  
Conventional Solid State Reaction ◽  
Reaction Phase ◽  
Tetragonal Unit Cell ◽  
Phase Pure ◽  
Very High ◽  
Centrosymmetric Structure

Fresnoite with composition Ba2TiSi2O8 (B2TS2) was first found in 1965, adopting a non-centrosymmetric structure. It also reported to crystallize in a tetragonal unit cell with a=8.52Å and c=5.210Å leading to some possible application as hydrophone, transducer and second harmonic generation and low temperature co-fired ceramics (LTCC). B2TS2 were synthesized by conventional solid state reaction. Phase pure B2TS2 was obtained after heating the pellets at a final sintering temperature of 1230 °C in air at 92 h. Study found that Fresnoite B2TS2 is a type of materials which are not ferroelectric and instead show perfect dielectric insulator behaviour with resistance >106Ωcm at temperatures below 750°C and also shows nonideal debye respone. The activation energy for conduction of B2TS2 samples is very high, indicating that these materials are highly insulating.

scholarly journals Synthesis and Na+ Ion Conductivity of Stoichiometric Na3Zr2Si2PO12 by Liquid-Phase Sintering with NaPO3 Glass

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3790
Author(s):  
Yongzheng Ji ◽  
Tsuyoshi Honma ◽  
Takayuki Komatsu
Keyword(s):  
Solid State ◽  
Liquid Phase ◽  
Sintering Temperature ◽  
Liquid Phase Sintering ◽  
Ion Conductivity ◽  
X Ray Diffraction ◽  
Conventional Solid State Reaction ◽  
X Ray ◽  
Sintering Time ◽  
Lower Activation

Sodium super ionic conductor (NASICON)-type Na3Zr2Si2PO12 (NZSP) with the advantages of the high ionic conductivity, stability and safety is one of the most famous solid-state electrolytes. NZSP, however, requires the high sintering temperature about 1200 °C and long sintering time in the conventional solid-state reaction (SSR) method. In this study, the liquid-phase sintering (LPS) method was applied to synthesize NZSP with the use of NaPO3 glass with a low glass transition temperature of 292 °C. The formation of NZSP was confirmed by X-ray diffraction analyses in the samples obtained by the LPS method for the mixture of Na2ZrSi2O7, ZrO2, and NaPO3 glass. The sample sintered at 1000 °C for 10 h exhibited a higher Na+ ion conductivity of 1.81 mS/cm at 100 °C and a lower activation energy of 0.18 eV compared with the samples prepared by the SSR method. It is proposed that a new LPE method is effective for the synthesis of NZSP and the NaPO3 glass has a great contribution to the Na+ diffusion at the grain boundaries.

Effect of Technological Parameters on the Microstructure and Electrical Properties of ZnO Varistors

2013 ◽  
Vol 820 ◽  
pp. 208-211
Author(s):  
Li Li ◽  
Qi Bin Liu
Keyword(s):  
Solid State ◽  
Electrical Properties ◽  
Leakage Current ◽  
Sintering Temperature ◽  
Voltage Gradient ◽  
Technological Parameters ◽  
Reaction Route ◽  
Conventional Solid State Reaction ◽  
Zno Varistors ◽  
Solid State Reaction Route

To improve voltage-gradient and to reduce the sintering temperature of ZnO varistors, high voltage-gradient ZnO varistors were synthesized with a conventional solid state reaction route. By means of SEM and DC parameter instrument for varistor, the influence of different technological parameters on microstructure, voltage-gradient and leakage current of ZnO varistors was investigated. The experimental results show that by using the process that presintering the additives at 850°C, the density is improved, the voltage-gradient is increased, and the leakage current is decreased. The optimum voltage-gradient and leakage current are 371V/mm and 3μA, respectively.

Molten Salt Synthesis of Nanocrystalline Phase of High Dielectric Constant Material CaCu3Ti4O12

2008 ◽  
Vol 8 (11) ◽  
pp. 5762-5769 ◽  
Author(s):  
B. Shri Prakash ◽  
K. B. R. Varma
Keyword(s):  
Dielectric Constant ◽  
Grain Size ◽  
Solid State ◽  
Molten Salt ◽  
Solid State Reaction ◽  
Molten Salt Synthesis ◽  
Reaction Route ◽  
Conventional Solid State Reaction ◽  
Phase Pure ◽  
Solid State Reaction Route

Nanocrystalline powders of giant dielectric constant material, CaCu3Ti4O12 (CCTO), have been prepared successfully by the molten salt synthesis (MSS) using KCl at 750 °C/10 h, which is significantly lower than the calcination temperature (∼1000 °C) that is employed to obtain phase pure CCTO in the conventional solid-state reaction route. The water washed molten salt synthesized powder, characterized by X-ray powder diffraction (XRD), Scanning electron microscopy (SEM), and Transmission electron microscopy (TEM) confirmed to be a phase pure CCTO associated with ∼150 nm sized crystallites of nearly spherical shape. The decrease in the formation temperature/duration of CCTO in MSS method was attributed to an increase in the diffusion rate or a decrease in the diffusion length of reacting ions in the molten salt medium. As a consequence of liquid phase sintering, pellets of as-synthesized KCl containing CCTO powder exhibited higher sinterability and grain size than that of KCl free CCTO samples prepared by both MSS method and conventional solid-state reaction route. The grain size and the dielectric constant of KCl containing CCTO ceramics increased with increasing sintering temperature (900 °C–1050 °C). Indeed the dielectric constants of these ceramics were higher than that of KCl free CCTO samples prepared by both MSS method and those obtained via the solid-state reaction route and sintered at the same temperature. Internal barrier layer capacitance (IBLC) model was invoked to correlate the observed dielectric constant with the grain size in these samples.

Effect of Sintering Temperature on Properties of Multiferroic BaFe12O19/MgFe2O4/BaTiO3 Composites

2016 ◽  
Vol 846 ◽  
pp. 410-415
Author(s):  
M.F.A. Zolkepli ◽  
Rozidawati Awang ◽  
Zalita Zainuddin
Keyword(s):  
Grain Size ◽  
Solid State ◽  
Electrical Properties ◽  
Sintering Temperature ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
Solid State Reaction Technique ◽  
Conventional Solid State Reaction ◽  
Different Temperatures ◽  
Tetragonal Batio

In this paper, the structural, magnetic and electrical properties of multiferroic BaFe12O19/MgFe2O4/BaTiO3 composites have been studied. BaFe12O19/MgFe2O4/BaTiO3 composites were synthesized by using the conventional solid state reaction technique and sintered at different temperatures. XRD analysis confirmed the existence of hexagonal BaFe12O19, cubic spinel MgFe2O4 and tetragonal BaTiO3 for ferrites and ferroelectric phases, respectively. The suitable sintering temperature for preparing BaFe12O19/MgFe2O4/BaTiO3 composites is between 1000 °C and 1050 °C. SEM analysis showed that as a whole the grain size increases and the pores is reduced with sintering temperature; thus the sample became denser. The coercive field and saturation magnetization decreases when sintering temperature is increased. Resistance of the samples decrease from 103 kW to 19 kW while the capacitance increases from 0.8 nF to 4.0 nF with sintering temperature.

Preparation and Thermoelectric Properties of LaCoO3 Ceramics

2010 ◽  
Vol 434-435 ◽  
pp. 404-408 ◽  
Author(s):  
Li Fu ◽  
Jing Feng Li
Keyword(s):  
Electrical Conductivity ◽  
Solid State ◽  
Thermoelectric Properties ◽  
Sintering Temperature ◽  
Conventional Solid State Reaction ◽  
Seebeck Coefficients ◽  
Different Temperatures ◽  
Higher Temperature ◽  
Increasing Temperature ◽  
Semiconducting Behavior

LaCoO3 ceramics were prepared by conventional solid state reaction and normal sintering at the temperatures ranging from 1373 to 1523 K. The sintered densities increased with increasing sintering temperature and exceeded 90 % of the theoretical values when sintered above 1473 K. The thermoelectric properties of the samples sintered at different temperatures were investigated from 323 to 673 K. The LaCoO3 samples showed a negative Seebeck coefficient, whose absolute values decreased dramatically with increasing temperature in the range of 323 to 460 K, then changed to a positive value and lightly decreased above 460 K. The electrical conductivity increased with increasing temperature, indicating a semiconducting behavior. The Seebeck coefficients showed little difference between the samples sintered at different temperatures, but the power factor of the sample sintered at a higher temperature was larger because of the higher electrical conductivity.

scholarly journals Submicron Sized Nb Doped Lithium Garnet for High Ionic Conductivity Solid Electrolyte and Performance of All Solid-State Lithium Battery

2019 ◽  
Author(s):  
Yan Ji ◽  
Cankai Zhou ◽  
Feng Lin ◽  
Bingjing Li ◽  
Feifan Yang ◽  
...  
Keyword(s):  
Activation Energy ◽  
Particle Size ◽  
Solid State ◽  
Ionic Conductivity ◽  
Relative Density ◽  
Specific Capacity ◽  
Cubic Phase ◽  
Conventional Solid State Reaction ◽  
Electrochemical Window ◽  
Total Ionic Conductivity

The garnet Li7La3Zr2O12 (LLZO) has been widely investigated because of its high conductivity, wide electrochemical window and chemical stability to lithium metal. However, the usual preparation process of LLZO requires a long time of high-temperature sintering and a lot of mother powders against the lithium evaporation. The submicron Li6.6La3Zr1.6Nb0.4O12 (LLZNO) powders are prepared by conventional solid-state reaction method and attrition milling process, which are stable cubic phase and have high sintering activity, and Li stoichiometric LLZNO ceramics are obtained by sintering at a relative lower temperature or for a short time by using these powders which are difficult to control under high sintering temperature and long sintering time. The particle size distribution, phase structure, microstructure, distribution of element, total ionic conductivity, relative density and activation energy of submicron LLZNO powders and LLZNO ceramics are tested and analyzed by laser diffraction particle size analyzer, XRD, SEM, EIS and Archimedean method. The total ionic conductivity of sample sintered at 1200 °C for 30 min is 5.09 × 10-4 S·cm-1, the activation energy is 0.311 eV, and the relative density is 87.3%, and sintered at 1150 °C for 60 min total ionic conductivity is 3.49 × 10-4 S·cm-1, the activation energy is 0.316 eV, and the relative density is 90.4%. At the same time, all-solid-state batteries are assembled with LiMn2O4 as positive electrode and submicron LLZNO powders as solid state electrolyte. After 50 cycles, the discharge specific capacity is 105.5 mAh/g and the columbic efficiency is above 95%.

Preparation and Microwave Dielectric Properties of Ca(Sm0.5Nb0.5)O3 Ceramics

2012 ◽  
Vol 512-515 ◽  
pp. 1198-1202
Author(s):  
Jia Mao Li ◽  
Tai Qiu
Keyword(s):  
Dielectric Properties ◽  
Solid State ◽  
Cooling Rate ◽  
Sintering Temperature ◽  
Microwave Dielectric Properties ◽  
Solid State Reaction Method ◽  
Sintering Process ◽  
Conventional Solid State Reaction ◽  
Reaction Method ◽  
Microwave Dielectric

Microstructures and microwave dielectric properties of Ca(Sm0.5Nb0.5)O3 ceramics, prepared by a conventional solid-state reaction method, were systematically investigated by varying calcining temperature, sintering temperature and cooling rate. The XRD result showed that a single Ca(Sm0.5Nb0.5)O3 phase could be synthesized at a calcining temperature of 1200 °C. Optimized combination of microwave dielectric properties of εr = 22.36, Q×f = 18030 GHz and τf = -31.2 ppm/°C was obtained for furnace-cooled Ca(Sm0.5Nb0.5)O3 ceramics sintered at 1550 °C for 4 h. However, some microcracks were found from the microstructures of the furnace-cooled specimens. Further, the Q×f value could be increased by controlling the cooling rate during the sintering process due to the disappearance of microcracks in the final material. With a cooling rate of 2 °C/min, Ca(Sm0.5Nb0.5)O3ceramics exhibited an enhanced Q×f value of 37130 GHz.

Influence of sintering temperature on structure, microstructure and piezoelectric properties of doped BZT–BCT ceramics

2017 ◽  
Vol 31 (02) ◽  
pp. 1650258 ◽  
Author(s):  
Anh Tuan Dang ◽  
Thanh Tung Vo ◽  
Van Chuong Truong ◽  
Van Hong Le
Keyword(s):  
Solid State ◽  
Piezoelectric Properties ◽  
Sintering Temperature ◽  
Solid State Reaction Method ◽  
Sintering Behavior ◽  
Zno Nanoparticle ◽  
Conventional Solid State Reaction ◽  
Reaction Method ◽  
Best Parameters ◽  
Better Than

This work reports the influence of sintering temperature on structure, microstructure and piezoelectric properties of 0.48 Ba(Zr[Formula: see text]Ti[Formula: see text])O3–0.52 (Ba[Formula: see text]Ca[Formula: see text])TiO3(BZT–BCT) doped with ZnO nanoparticle ceramics manufactured by a conventional solid state reaction method. By increasing sintering temperature, the piezoelectric behaviors were improved and rose up to the best parameters at a sintering temperature of 1450[Formula: see text]C ([Formula: see text] pC/N and [Formula: see text]). The corresponding properties of undoped BZT–BCT ceramics were investigated as a comparison. The received results show that the sintering behavior and piezo-parameters of doped BZT–BCT samples are better than the undoped BZT–BCT samples at each sintering temperature.

EFFECT OF SINTERING TEMPERATURE ON THE MICROSTRUCTURE AND THERMOELECTRIC PROPERTIES OF Ca2.7Bi0.3Co4O9

2009 ◽  
Vol 23 (18) ◽  
pp. 3777-3787 ◽  
Author(s):  
HAOSHAN HAO ◽  
SHAOFENG LI ◽  
LIMIN ZHAO ◽  
XING HU
Keyword(s):  
Solid State ◽  
Transport Properties ◽  
Thermoelectric Properties ◽  
Solid State Reaction ◽  
Sintering Temperature ◽  
Solid State Reaction Method ◽  
Conventional Solid State Reaction ◽  
Reaction Method ◽  
Cooling Stage ◽  
Oriented Structure

Ca 2.7 Bi 0.3 Co 4 O 9 samples have been sintered in temperature range of 1183–1243 K by conventional solid-state reaction method. XRD and SEM investigations show that c-axis-oriented structure could be formed in these samples and Lotgering factors increase with the increase of sintering temperature when it is below 1223 K, from 52% for the sample sintered at 1183 K to 86% for the sample sintered at 1223 K. Due to decomposition of Ca 2.7 Bi 0.3 Co 4 O 9, however, the c-axis-oriented structure was destroyed in the sample sintered at 1243 K although Ca 2.7 Bi 0.3 Co 4 O 9 phase could be recovered at the cooling stage. The size of grains in all samples increases with the increase of sintering temperature, but the relative densities are almost kept unchanged for the samples sintered at the temperature higher than 1183 K. Due to the highly textured structure, the transport properties of the sample sintered at 1223 K are anisotropic and its ZT values in the ab plane are obviously larger than those along the c-axis.

scholarly journals Preparation, Sinterability, Electrical Transport and Thermal Expansion of Perovskite-Type La0.8Ca0.2CrO3 Composites

2020 ◽  
Vol 10 (13) ◽  
pp. 4634
Author(s):  
Linlin Liu ◽  
Mingmei Jiang ◽  
Juanjuan Yin ◽  
Wenfeng Guo ◽  
Tifeng Jiao
Keyword(s):  
Electrical Conductivity ◽  
Thermal Expansion ◽  
Solid State ◽  
Electrical Transport ◽  
Sintering Temperature ◽  
Electronic Conductivity ◽  
Combustion Method ◽  
Synthesis Methods ◽  
Conventional Solid State Reaction ◽  
Perovskite Type

Perovskite-type was synthesized by two methods, the combustion method and conventional solid state reaction (SSR) method. The effect of synthesis methods on sinterability and physical properties of the ceramic were investigated. The results show that there are advantages of the combustion method in producing doped lanthanum chromites. Compared with the SSR method, the combustion method reduces the sintering temperature of La0.8Ca0.2CrO3, elevates the electronic conductivity and thermal expansion coefficient (TEC) of the ceramic, due to optimizing the microstructure. At the same densities level (–93%), the specimen synthesized by the combustion method reaches a superior electrical conductivity of 31.6 S·cm-1 and a compatible TEC of 10.7 × 10−6 K−1 at 800 °C.

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