Effect of Different Doping on the Structure and Field-Stability of PMNT Ceramics

2007 ◽  
Vol 336-338 ◽  
pp. 36-38
Author(s):  
Xiao Wei Wen ◽  
Chu De Feng ◽  
Li Dong Chen ◽  
Shi Ming Huang
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Perovskite Structure ◽  
Single Phase ◽  
Secondary Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Co Doping ◽  
Diffraction Patterns

Effect of co-doping two different elements and incorporating SrBi2Nb2O9 (SBN) on structure and field-stability of dielectric properties in PMNT ceramics were investigated. Single-phase cubic Perovskite structure is more easily obtained by appropriate co- doping of La3+ and Zn2+. X-ray diffraction patterns of PMNT/SBN composite showed that there is no SBN grains in PMNT/SBN as a secondary phase. Co-doping of La3+ and Zn2+ as well as incorporation of SBN markedly increased the field-stability of dielectric constant. The mechanism of improving field-stability was tentatively discussed.

scholarly journals Effect of Zr4+ Content on Crystal Structure, Micromorphology and Dielectric Properties of Ba(Zrx Ti1-X)O3 Ceramics

2019 ◽  
Vol 3 (1) ◽  
Keyword(s):  
Crystal Structure ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
Great Influence ◽  
Secondary Phase ◽  
Solid State Reaction Method ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffraction Patterns

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.

scholarly journals Investigations on Structural, Mechanical, and Dielectric Properties of PVDF/Ceramic Composites

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Anshuman Srivastava ◽  
Karun Kumar Jana ◽  
Pralay Maiti ◽  
Devendra Kumar ◽  
Om Parkash
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Single Phase ◽  
Extrusion Process ◽  
Ceramic Composites ◽  
X Ray Diffraction ◽  
Composite State ◽  
X Ray ◽  
Embedded Capacitor ◽  
Xrd Patterns

Polymer ceramic composites are widely used for embedded capacitor application. In the present work PVDF has been used as a matrix and CCTO and LaCCTO have been used as reinforcement. Extrusion process has been used for the synthesis of composites. X-ray diffraction (XRD) patterns confirm the formation of single phase CCTO, and LaCCTO in its pure as well as composite state. It is found that La doping in CCTO considerably increases the dielectric constant and reduces the dielectric loss. A similar trend is observed in the composites with the increasing content of CCTO and LaCCTO.

Low-Temperature Sintering of Ba5(Nb1-xVx)4O15 Ceramics with H3BO3

2008 ◽  
Vol 368-372 ◽  
pp. 132-135 ◽  
Author(s):  
C. Zhang ◽  
Hong Qiu ◽  
Zhao Xian Xiong
Keyword(s):  
Dielectric Properties ◽  
Single Phase ◽  
Microwave Dielectric Properties ◽  
Secondary Phase ◽  
Dielectric Constants ◽  
Low Temperature Sintering ◽  
X Ray ◽  
Microwave Dielectric ◽  
Unloaded Quality Factor ◽  
Diffraction Patterns

Ba5(Nb1-xVx)4O15 (0≤x≤0.1) ceramics doped with H3BO3 were prepared by solid-state reaction. The effects of H3BO3 additives on the sinterability and microwave dielectric properties of the ceramics were investigated. The formation of a single phase was identified with the X-ray powder diffraction patterns of Ba5(Nb1-xVx)4O15 ceramics in the composition x from 0 to 0.025. Minor phases including Ba3(VO4)2 were formed as the secondary phase for the compositions with x>0.025. The dielectric constants (εr) of the ceramics increased firstly from 38.7 to 39.69 with x increasing from 0 to 0.01, and, then decreased to 36.91 with x=0.1, meanwhile, the unloaded quality factor and temperature coefficient of resonance frequency (τf) decreased as the x value increased from 0 to 0.1. Microwave dielectric properties, εr=36.91, Q×f =16,167GHz and τf =35ppm/°C, were obtained for Ba5(Nb0.9V0.1)4O15 ceramics with 1wt% H3BO3 sintered at 900°C for 2h.

scholarly journals Effects of barium substitution on the sintering behavior, dielectric properties of Ca2Nb2O7 ferroelectric ceramics

2017 ◽  
Vol 07 (02) ◽  
pp. 1750013 ◽  
Author(s):  
Chunchun Li ◽  
Huaicheng Xiang ◽  
Yuandong Qin ◽  
Liang Fang
Keyword(s):  
Phase Transition ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
Secondary Phase ◽  
Solubility Limit ◽  
Ferroelectric Ceramics ◽  
Sintering Behavior ◽  
X Ray Diffraction ◽  
Spectroscopy Analysis ◽  
X Ray

Barium-doped Ca2Nb2O7 ceramics were prepared in the form of Ca[Formula: see text]BaxNb2O7 (0 [Formula: see text] 0.6) by solid-state reaction. The solubility limit of barium in Ca2Nb2O7 was found to be [Formula: see text] based on X-ray diffraction and Raman spectroscopy analysis. When [Formula: see text] 0.4, Ca[Formula: see text]BaxNb2O7 solid solutions with a monoclinic perovskites-like layered structure (PLS) were formed, whereas beyond [Formula: see text], a secondary phase CaNb2O6 was detected. The dielectric properties obviously depended on the barium substitution. With increasing barium amount, the dielectric constant increased from 33.5 for pure Ca2Nb2O7 to 38.6 for [Formula: see text] ([Formula: see text][Formula: see text]MHz). The Curie temperature ([Formula: see text] of the [Formula: see text] sample was 1280[Formula: see text][Formula: see text][Formula: see text]5[Formula: see text]C. The phase transition was confirmed to be the second order.

scholarly journals Structural and Dielectric Properties of (1-x) (Al0.2La0.8TiO3) + (x) (BiZnFeO3) (x = 0.2 - 0.8) Nanocomposites

2021 ◽  
Author(s):  
A. Mallikarjuna ◽  
N. Suresh Kumar ◽  
T. Anil Babu ◽  
S. Ramesh ◽  
Chandra Babu Naidu K
Keyword(s):  
Electrical Conductivity ◽  
Dielectric Constant ◽  
Phase Transformation ◽  
Dielectric Properties ◽  
Dielectric Behavior ◽  
Perfect Absorber ◽  
X Ray Diffraction ◽  
Ac Electrical Conductivity ◽  
X Ray ◽  
Diffraction Patterns

Abstract (1-x) (Al0.2La0.8TiO3) + (x) (BiZnFeO3) (x = 0.2 - 0.8) [ALTBZFO] nanocomposites were synthesized via hydrothermal method. The X-ray diffraction patterns indicated the phase transformation from tetragonal to cubic for x = 0.2 to 0.4 - 0.8 samples, respectively. The surface morphology showed the existence of nanospheres like structures. At 1 MHz frequency also, the dielectric constant was increased from 230 to 710 for x = 0.2 – 0.6 samples, respectively. But, interestingly, x = 0.6 nanocomposite exhibited the negative dielectric behavior having the dielectric constant (ε') ~ -58.5 and dielectric loss (ε") ~ -417 at 8 MHz. Likewise, x = 0.6 sample showed ac-electrical conductivity (σac) -0.159 S/cm at 6 MHz. Hence, these kinds of materials can provide high charge stored capacitor, and perfect absorber applications.

Dielectric and Piezoelectric Properties of xPb(Ni1/3Nb2/3)O3 - yPb(Mn1/3Nb1/3Sb1/3)O3- (1-x-y)Pb(Zr0.48Ti0.52)O3 Ceramics

2006 ◽  
Vol 317-318 ◽  
pp. 849-852
Author(s):  
Hua Jun Sun ◽  
Wen Chen ◽  
Xiao Fang Liu ◽  
Qing Xu ◽  
Jing Zhou ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Curie Temperature ◽  
Perovskite Structure ◽  
Single Phase ◽  
Piezoelectric Properties ◽  
X Ray Diffraction ◽  
Step Method ◽  
X Ray ◽  
Curie Temperature Tc ◽  
Dielectric And Piezoelectric Properties

xPb(Ni1/3Nb2/3)O3-yPb(Mn1/3Nb1/3Sb1/3)O3-(1-x-y)Pb(Zr0.48Ti0.52)O3 ceramics have been prepared by a columbite two-step method. NiNb2O6, MnNb2O6 and MnSb2O6 were used as precursors to produce the pseudoquintnary system ceramics. X-ray diffraction (XRD) results indicate that the pseudoquintnary system ceramics have a single-phase perovskite structure. The piezoelectric and dielectric properties of the ceramics were investigated as functions of x or y. The addition of Pb(Ni1/3Nb2/3)O3 makes the piezoelectric properties to become ‘soft’, while the addition of Pb(Mn1/3Nb1/3Sb1/3)O3 makes the piezoelectric properties to be ‘hard’. The Curie temperature (Tc) of the pseudoquintnary system decreases with the increase of Pb(Ni1/3Nb2/3)O3 or Pb(Mn1/3Nb1/3Sb1/3)O3 contents. The preferred piezoelectric properties were obtained in the composition with x=0.06 and y=0.06.

INVESTIGATIONS ON Sm- AND Nb-SUBSTITUTED PZT CERAMICS

2006 ◽  
Vol 20 (29) ◽  
pp. 1879-1882 ◽  
Author(s):  
CHANDRA PRAKASH ◽  
J. K. JUNEJA
Keyword(s):  
Dielectric Constant ◽  
Single Phase ◽  
Xrd Analysis ◽  
Chemical Formula ◽  
X Ray Diffraction ◽  
Pzt Ceramics ◽  
Ceramic Method ◽  
X Ray ◽  
Niobium Doping ◽  
Constant Versus

In the present paper, we report the effect of Samarium substitution and Niobium doping on the properties of a PZT(52:48). The properties studied are: structural, dielectric and ferroelectric. The samples with chemical formula Pb 0.99 Sm 0.01 Zr 0.52 Ti 0.48 O 3 were prepared by solid-state dry ceramic method. Small amount (0.5 wt%) of Nb 2 O 5 was also added. X-ray diffraction (XRD) analysis showed formation of a single phase with tetragonal structure. Dielectric properties were studied as a function of temperature and frequency. Transition temperature, Tc, was determined from dielectric constant versus temperature plot. The material shows well-defined ferroelectric (PE) hysteresis loop.

Phase Development and Dielectric Properties of 0.98BaTiO3-0.02Ba (Mg1/3Nb2/3) O3 Ceramic

2011 ◽  
Vol 700 ◽  
pp. 58-62
Author(s):  
Rachanusorn Roongtao ◽  
Supagorn Rugmai ◽  
Wanwilai C. Vittayakorn
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
Loss Factor ◽  
X Ray Diffraction ◽  
Phase Purity ◽  
X Ray ◽  
Phase Development ◽  
Scanning Electron

The 0.98BaTiO3-0.02Ba (Mg1/3Nb2/3) O3ceramics has been synthesized through a conventional mixed-oxide by using BT nanopowder and BMN micropowder. The phase purity of the powders and the ceramics was examined using X-ray diffraction (XRD). The 0.98BT-0.02BMN powders were sintered to 92% of the theoretical density at a temperature of 1300 °C for 2 h. The microstructure of the sintered surface was investigated using scanning electron microscopy (SEM). The dielectric constant (εr) and loss factor (tanδ) of the sintered pellets at Curie temperture were 3000 and 0.015, respectively.

scholarly journals Sintering behaviour and microwave dielectric properties of MgO-2B2O3-xwt%BaCu(B2O5)-ywt%H3BO3 ceramics

2021 ◽  
Author(s):  
Haiquan Wang ◽  
Shixuan Li ◽  
Kangguo Wang ◽  
Xiuli Chen ◽  
Huanfu Zhou
Keyword(s):  
Dielectric Properties ◽  
Bulk Density ◽  
Single Phase ◽  
Sintering Temperature ◽  
Microwave Dielectric Properties ◽  
X Ray Diffraction ◽  
Microwave Dielectrics ◽  
X Ray ◽  
Microwave Dielectric ◽  
Sintering Behaviour

AbstractThis study investigates the bulk density, sintering behaviour, and microwave dielectric properties of the MgO-2B2O3 series ceramics synthesised by solid-state reaction. According to the X-ray diffraction and microstructural analyses, the as-prepared MgO-2B2O3 ceramics possess a single-phase structure with a rod-like morphology. The effects of different quantities of H3BO3 and BaCu(B2O5) (BCB) on the bulk density, sintering behaviour, and microwave dielectric properties of the MgO-2B2O3 ceramics were investigated. Accordingly, the optimal sintering temperature was obtained by adding 30 wt% H3BO3 and 8 wt% BCB. We also reduced the sintering temperature to 825 °C. Furthermore, the addition of 40 wt% H3BO3 and 4 wt% BCB increased the quality factor, permittivity, and temperature coefficient of resonance frequency of MgO-2B2O3 to 44,306 GHz (at 15 GHz), 5.1, and −32 ppm/°C, respectively. These properties make MgO-2B2O3 a viable low-temperature co-fired ceramic with broad applications in microwave dielectrics.

scholarly journals Structure and electric properties of cerium substituted SrBi1.8Ce0.2Nb2O9 and SrBi1.8Ce0.2Ta2O9 ceramics

2016 ◽  
Vol 10 (3) ◽  
pp. 183-188 ◽  
Author(s):  
Mohamed Afqir ◽  
Amina Tachafine ◽  
Didier Fasquelle ◽  
Mohamed Elaatmani ◽  
Jean-Claude Carru ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Solid State ◽  
Room Temperature ◽  
Single Phase ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
Reaction Method ◽  
X Ray ◽  
Lcr Meter ◽  
Curie Temperature Tc

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.

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