Effect of Annealing on the Structure and Dielectric Properties in PZT-PCoN Ceramics

2008 ◽  
Vol 55-57 ◽  
pp. 49-52
Author(s):  
Naratip Vittayakorn ◽  
N. Chaiyo ◽  
R. Muanghlua ◽  
A. Ruangphanit ◽  
Wanwilai C. Vittayakorn

he solid solution between the normal ferroelectric Pb(Zr1/2Ti1/2)O3 (PZT) and relaxor ferroelectric Pb(Co1/3Nb2/3)O3 (PCoN) was synthesized by the solid state reaction method. Sintered PZT-PCoN ceramics were annealed at temperatures ranging from 850 to 1,100°C for 4 h. X-ray diffraction patterns revealed changes of crystalline structure after annealing, which could be correlated to the accompanied changes in dielectric properties. Furthermore, significant improvements in the dielectric responses were observed in this system. After annealing, a huge increase of up to 200% occurred in the dielectric constants, especially near the temperature of maximum dielectric constant.

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Chia-Ching Wu ◽  
Cheng-Fu Yang

Abstract Strontium bismuth tantalate vanadate [SrBi2(Ta2−xVx)O9, SBTV] ceramics, which are bismuth-layered perovskite ferroelectrics, were synthesized through the solid-state reaction method. The effects of different sintering temperatures and V2O5 contents on the structure of the microstructure, Raman spectrum, and dielectric properties of the SBTV ceramics were investigated. As sintered at high temperature (980–1040 °C) and different V2O5 contents (x = 0.1 − x = 0.4), only disk-like grains of the SBTV ceramics were observed in the scanning electron micrographs. Preferential orientation of the crystals of the SBTV ceramics was confirmed through X-ray diffraction studies. The higher dielectric constant and Curie temperature of the SBTV ceramics compared with those of strontium bismuth tantalite (SrBi2Ta2O9, SBT) ceramics are ascribe to the partial replace of Ta5+ ions by V5+ ions in the B sites. The Curie–Weiss law and the modified Curie–Weiss law were used to discuss the normal-type or relaxor-type ferroelectric characteristic of the SBTV ceramics. The Ta5+ ion replaced by V5+ ion site in SBT ceramics to form SBTV ceramics exerted a pronounced effect on the BO6 mode, as demonstrated by Raman spectrum results.


2012 ◽  
Vol 585 ◽  
pp. 219-223
Author(s):  
Rekha Kumari ◽  
N. Ahlawat ◽  
Ashish Agarwal ◽  
M. Sindhu ◽  
N.N. Ahlawat

Na0.5Bi0.5TiO3 (NBT) ceramics were synthesized by conventional solid state reaction method. Structural and dielectric properties of these ceramics were investigated. Crystalline phase of sintered ceramics was investigated by X-ray diffraction (XRD). The Rietveld refinement of powder X-ray diffraction revealed that the prepared ceramics exhibit the rhombohedral space group R3c. Dielectric properties of Na0.5Bi0. analyzer.5TiO3 (NBT) ceramics were studied at different temperatures in a wide frequency range using impedance


2019 ◽  
Vol 3 (1) ◽  

Ba(Zrx Ti1-x)O3 ceramics (X=1.5, 2.0, 2.5, 3.0) were prepared by solid-state reaction method. Effect of controlling the ratio of Zr/Ti on the crystal structure, micromorphology and dielectric properties of BZT ceramics. Their crystal structures, morphologies, and electric properties were respectively characterized using X-ray diffraction, scanning electron microscope and impedance analyzer. The X-ray diffraction patterns show that the zirconium titanate ceramic samples behave cubic phase structure and no secondary phase. The ratio of Zr/Ti has a great influence on the crystal structure, microstructure and dielectric properties. As the Zr4+ content increases, the lattice constant increases and the grain size decreases. The dielectric constant is the largest when the Zr content is 15%. As the Zr4+ content increases, the dielectric constant decreases gradually, and the Curie temperature moves toward the low temperature region.


2010 ◽  
Vol 663-665 ◽  
pp. 608-611
Author(s):  
Cui Jin Pei ◽  
Guo Guang Yao ◽  
Xiu Lao Tian ◽  
Hong Ma

The effects of Li2CO3-V2O5 (LV) co-doped on the sinterability, phase compositions and microwave dielectric properties of 0.6Mg4Nb2O9-0.4SrTiO3 composite ceramics have been investigated. All specimens were prepared by solid-state reaction method and sintered at 1050-1200oC for 5h. With an amount LV addition, the densification sintering temperature is significantly lowed from 1300oC to 1175oC. The non-stoichiometric compounds Sr(NbTi)O3+δ and Mg4(Nb1-xTix)2O9-δ were confirmed by X-ray diffraction and energy dispersive X-ray analysis. For the specimen with 1.5 wt% LV addition sintered at 1175oC for 5 h exhibited dielectric properties: εr=20.1, Q•f=10 240 GHz, τf =0.15 ppm/oC.


2016 ◽  
Vol 34 (2) ◽  
pp. 412-417
Author(s):  
Esra Öztürk

AbstractIn this work, aluminate type phosphorescence materials were synthesized via the solid state reaction method and the photoluminescence (PL) properties, including excitation and emission bands, were investigated considering the effect of trace amounts of activator (Eu3+) and co-activator (Dy3+). The estimated thermal behavior of the samples at certain temperatures (> 1000 °C) during heat treatment was characterized by differential thermal analysis (DTA) and thermogravimetry (TG). The possible phase formation was characterized by X-ray diffraction (XRD). The morphological characterization of the samples was performed by scanning electron microscopy (SEM). The PL analysis of three samples showed maximum emission bands at around 610 nm, and additionally near 589 nm, 648 nm and 695 nm. The bands were attributed to typical transitions of the Eu3+ ions.


2015 ◽  
Vol 5 (01) ◽  
pp. 31
Author(s):  
Resky Irfanita ◽  
Asnaeni Ansar ◽  
Ayu Hardianti Pratiwi ◽  
Jasruddin J ◽  
Subaer S

The objective of this study is to investigate the effect of sintering temperature on the synthesis of SiC produced from rice husk ash (RHA) and 2B graphite pencils. The SiC was synthesized by using solid state reaction method sintered at temperatures of 750°C, 1000°C and 1200°C for 26 hours, 11.5 hours and 11.5 hours, respectively. The quantity and crystallinity level of SiC phase were measured by means of Rigaku MiniFlexII X-Ray Diffraction (XRD). The microstructure of SiC was examined by using Tescan Vega3SB Scanning Electron Microscopy (SEM). The XRD results showed that the concentration (wt%) of SiC phase increases with the increasing of sintering temperature. SEM results showed that the crystallinity level of SiC crystal is improving as the sintering temperature increases


2016 ◽  
Vol 10 (3) ◽  
pp. 183-188 ◽  
Author(s):  
Mohamed Afqir ◽  
Amina Tachafine ◽  
Didier Fasquelle ◽  
Mohamed Elaatmani ◽  
Jean-Claude Carru ◽  
...  

SrBi1.8Ce0.2Nb2O9 (SBCN) and SrBi1.8Ce0.2Ta2O9 (SBCT) powders were prepared via solid-state reaction method. X-ray diffraction analysis reveals that the SBCN and SBCT powders have the single phase orthorhom-bic Aurivillius structure at room temperature. The contribution of Raman scattering and FTIR spectroscopy of these samples were relatively smooth and resemble each other. The calcined powders were uniaxially pressed and sintered at 1250?C for 8 h to obtaine dense ceramics. Dielectric constant, loss tangent and AC conductivity of the sintered Ce-doped SrBi2Nb2O9 and SrBi2Ta2O9 ceramics were measured by LCR meter. The Ce-doped SBN (SBCN) ceramics have a higher Curie temperature (TC) and dielectric constant at TC (380?C and ?? ~3510) compared to the Ce-doped SBT (SBCT) ceramics (330?C and ?? ~115) when measured at 100Hz. However, the Ce-doped SBT (SBCT) ceramics have lower conductivity and dielectric loss.


Author(s):  
Hongqiang Cui ◽  
Yongze Cao ◽  
Lei Zhang ◽  
Yuhang Zhang ◽  
Siying Ran ◽  
...  

Er3+ with different concentrations doped K2Yb(PO4)(MoO4) phosphors were prepared by a solid-state reaction method, and the layered orthorhombic crystal structure of the samples was confirmed by X-ray diffraction (XRD). Under...


2021 ◽  
Vol 321 ◽  
pp. 23-27
Author(s):  
Simona Ravaszová ◽  
Karel Dvořák

The paper is focused on one of the most important component of Portland clinker-on the tricalcium silicate. The study reported in this article is focuses on the changes in crystallite size of synthetic tricalcium silicate obtained using solid state reaction method. Crystallite size changes are monitored during the grinding in three types of laboratory mills in two different conditions. Changing in crystallite size at various grinding time up to 120 minutes are studied with the aid of X-ray diffraction and using the Scherrer equation. It has been found that the most efficient laboratory mill in terms of speed and fineness of the material was the planetary mill.


1985 ◽  
Vol 49 (353) ◽  
pp. 547-554 ◽  
Author(s):  
M. Shahmiri ◽  
S. Murphy ◽  
D. J. Vaughan

AbstractThe crystal structure and compositional limits of the ternary compound Pt2FeCu (tulameenite), formed either by quenching from above the critical temperature of 1178°C or by slow cooling, have been investigated using X-ray diffraction, transmission electron microscopy, differential thermal analysis and electron probe microanalysis.The crystal structure of Pt2FeCu, established using electron density maps constructed from the measured and calculated intensities of X-ray diffraction patterns of powdered specimens, has the (000) and (½½0) lattice sites occupied by Pt atoms and the (½0½) and (0½½) sites occupied by either Cu or Fe atoms in a random manner. The resulting face-centred tetragonal structure undergoes a disordering transformation at the critical temperature to a postulated non-quenchable face-centred cubic structure. Stresses on quenching, arising from the ordering reaction, are relieved by twinning along {101} planes or by recrystallization along with deformation twinning; always involving grain boundary fracturing.Phase relations in the system Pt-Fe-Cu have been investigated through the construction of isothermal sections at 1000 and 600°C. At 1000°C there is an extensive single phase region of solid solution around Pt2FeCu and extending to the binary composition PtFe. At 600°C the composition Pt2FeCu lies just outside this now reduced area of solid solution in a two-phase field. Comparison of the experimental results with data for tulameenite suggests that some observed compositions may be metastably preserved. The occurrence of fine veinlets of silicate or other gangue minerals in tulameenite is suggested to result from grain boundary fracturing on cooling below the critical temperature of 1178°C and to be evidence of a magmatic origin.


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