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Ceramic Route (ceramic + route)
Kinds of Ceramic Route Selected AbstractsMicrowave Dielectric Properties of SrO,2CeO2,nTiO2 (n=4 and 5) CeramicsINTERNATIONAL JOURNAL OF APPLIED CERAMIC TECHNOLOGY, Issue 2010Ramachandran Satheesh SrO,2CeO2,nTiO2 ceramics with n=4 and 5 have been prepared through conventional solid-state ceramic route. Structural and microstructural characterizations of the sintered ceramics were carried out using X-ray diffraction, laser Raman, and scanning electron microscopic studies. Microwave dielectric properties have been measured using postresonator and resonant cavity techniques. SrO,2CeO2,4TiO2 and SrO,2CeO2,5TiO2 ceramics showed dielectric constants of 71.3 and 71.7, respectively, around 4 GHz together with a relatively high unloaded quality factor. [source] A Novel Temperature-Compensated Microwave Dielectric (1,x)(Mg0.95Ni0.05)TiO3,xCa0.6La0.8/3TiO3 Ceramics SystemINTERNATIONAL JOURNAL OF APPLIED CERAMIC TECHNOLOGY, Issue 5 2009Chun-Hsu Shen The microstructure and microwave dielectric properties of a (1,x)(Mg0.95Ni0.05)TiO3,xCa0.6La0.8/3TiO3 ceramics system have been investigated. The system was prepared using a conventional solid-state ceramic route. In order to produce a temperature-stable material, Ca0.6La0.8/3TiO3 was added for a near-zero temperature coefficient (,f). With partial replacement of Mg2+ by Ni2+, the dielectric properties of the (1,x)(Mg0.95Ni0.05)TiO3,xCa0.6La0.8/3TiO3 ceramics can be promoted. The microwave dielectric properties are strongly correlated with the sintering temperature and the composition. An excellent Q × f value of 118,000 GHz can be obtained for the system with x=0.9 at 1325°C. For practical application, a dielectric constant (,r) of 24.61, a Q × f value of 102,000 GHz, and a temperature coefficient of resonant frequency (,f) of ,3.6 ppm/°C for 0.85(Mg0.95Ni0.05)TiO3,0.15Ca0.6La0.8/3TiO3 at 1325°C are proposed. A parallel-coupled line band-pass filter is designed and simulated using the proposed dielectric to study its performance. [source] The Effect of Dopants on the Dielectric Properties of Ba(B,1/2Ta1/2)O3 (B,=La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Y, Yb, and In) Microwave CeramicsINTERNATIONAL JOURNAL OF APPLIED CERAMIC TECHNOLOGY, Issue 5 2009Lamrat Abdul Khalam Low-loss dielectric ceramics based on Ba(B,1/2Ta1/2)O3 (B,=La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Y, Yb, and In) complex perovskites have been prepared by the solid-state ceramic route. The dielectric properties (,r, Qu, and ,f) of the ceramics have been measured in the frequency range 4,6 GHz by the resonance method. The resonators have a relatively high dielectric constant and high quality factor. Most of the compounds have a low coefficient of temperature variation of the resonant frequencies. The microwave dielectric properties have been improved by the addition of dopants and by solid solution formation. The solid solution Ba[(Y1,xPrx)1/2Ta1/2]O3 has x=0.15, with ,r=33.2, Qu×f=51,500 GHz, and ,f,0. The microwave dielectric properties of Ba(B,1/2Ta1/2)O3 ceramics are found to depend on the tolerance factor (t), ionic radius, and ionization energy. [source] Structural characterization of manganese-substituted nanocrystalline zinc oxide using small-angle neutron scattering and high-resolution transmission electron microscopyJOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 6 2009B. Roy A series of zinc oxide (ZnO) nanoparticles, substituted with manganese di-oxide, have been synthesized through a modified ceramic route using urea as a fuel. X-ray diffraction and high-resolution transmission electron microscopy studies indicate that the sizes of the ZnO particles are of nanometer dimension. Particles remain as single phase when the doping concentration is below 15,mol%. Small-angle neutron scattering indicates fractal-like agglomerates of these nanoparticles in powder form. The size distributions of the particles have been estimated from scattering experiments as well as microscopy studies. The average particle size estimated from small-angle scattering experiments was found to be somewhat more than that obtained from X-ray diffraction or electron microscopy measurement. [source] Microwave Dielectric Properties of SrRE4Si3O13 (RE=La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Er, Tm, Yb, and Y) CeramicsJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 12 2009Sherin Thomas The apatite type SrRE4Si3O13 (RE=La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Er, Tm, Yb, and Y) ceramics have been prepared by the conventional solid-state ceramic route. The phase purity and surface morphology of the sintered ceramics were studied using X-ray diffraction and scanning electron microscopy methods. These materials showed poor sinterability and was improved by the addition of a small weight percentage of zinc borosilicate glass. The microwave dielectric properties of these materials were studied for the first time. SrRE4Si3O13 ceramics have a low relative permittivity (,r) in the range 9,16, a Q-factor (Qu×f) upto 26 000 GHz and a low temperature coefficient of resonant frequency (,f). The SrLa4Si3O13 ceramics possessed a high Qu×f of nearly 26 000 GHz but with a high negative ,f of ,46 ppm/°C. The ,f of SrLa4Si3O13 ceramics was tuned by the addition of suitable amount of TiO2. [source] Low-Temperature Sintering and Microwave Dielectric Properties of Li2MgSiO4 CeramicsJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 6 2009Sumesh George Development of a low-temperature sintered dielectric material derived from Li2MgSiO4 (LMS) for low-temperature cofired ceramic (LTCC) application is discussed in this paper. The LMS ceramics were prepared by the solid-state ceramic route. The calcination and sintering temperatures of LMS were optimized at 850°C/4 h and 1250°C/2 h, respectively, for the best density and dielectric properties. The crystal structure and microstructure of the ceramic were studied by the X-ray diffraction and scanning electron microscopic methods. The microwave dielectric properties of the ceramic were measured by the cavity perturbation method. The LMS sintered at 1250°C/2 h had ,r=5.1 and tan ,=5.2 × 10,4 at 8 GHz. The sintering temperature of LMS is lowered from 1250°C/2 h to 850°C/2 h by the addition of both lithium borosilicate (LBS) and lithium magnesium zinc borosilicate (LMZBS) glasses. LMS mixed with 1 wt% LBS sintered at 925°C/2 h had ,r=5.5 and tan ,=7 × 10,5 at 8 GHz. Two weight percent LMZBS mixed with LMS sintered at 875°C/2 h had ,r=5.9 and tan ,=6.7 × 10,5 at 8 GHz. [source] Giant Permittivity of a Bismuth Zinc Niobate,Silver CompositeJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 11 2007Sumesh George Bismuth zinc niobate,Silver (BZN,Ag) composites were prepared by the solid-state ceramic route. The sintering temperature of BZN,Ag composites was lowered to 850°C/2 h. The structure and surface morphology of the composites were investigated using X-ray diffraction and optical microscope. The dielectric and conducting properties of the composites were systematically investigated with the volume fraction of silver in the frequency range from 1 KHz to 1 MHz. The dielectric constant of the composite increases with the silver content and is in good agreement with the power law below the percolation limit. Addition of 0.14 volume fraction of silver increases the dielectric constant of BZN+2 wt% B2O3 from 150 to 2350 at 1 MHz. However, 15 volume percentage of silver loading results in a large permittivity of (,r),105 with a low dielectric loss (tan ,,10,2) at 1 MHz. Subsequent increase in silver loading decreases the dielectric constant. The BZN,B2O3,Ag composite with large permittivity may find applications in electromechanical and tunable devices. [source] Preparation, Characterization, and Microwave Properties of RETiNbO6 (RE = Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Y, and Yb) Dielectric CeramicsJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 7 2001Mailadil T. Sebastian Microwave ceramic dielectric resonators (DRs) based on RETiNbO6 (RE = Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Y, and Yb) have been prepared using the conventional solid-state ceramic route. The DR samples are characterized using XRD and SEM methods. The microwave dielectric properties are measured using resonant methods and a net work analyzer. The ceramics based on Ce, Pr, Nd, and Sm have dielectric constants in the range 32,54 and positive coefficient of thermal variation of resonant frequency (,f). The ceramics based on Gd, Tb, Dy, Y, and Yb have dielectric constants in the range 19,22 and negative ,f. [source] Growth and characterization of Sn doped ZnO thin films by pulsed laser depositionPHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 6 2006E. López-Ponce Abstract Sn:ZnO thin films with different Sn concentrations were grown by pulsed laser deposition (PLD) onto single-crystal Si(001) substrates at an oxygen pressure of 2 × 10,2 mbar and substrate temperature of 600 °C. The targets used were high density Sn:ZnO pellets with different Sn concentrations produced by mixing ZnO and SnO2 by conventional ceramic routes. A deep structural and electrical characterization was carried out in order to determine the role of an increasing Sn nominal concentration on the ZnO film transport properties. Only films with a nominal 0.1 at% Sn show an improvement of the transport properties, lower resistivity and higher donor concentration, with respect to pure ZnO thin films. For films with larger Sn nominal concentrations segregated SnZnO phases appear that lead to larger film resistivities and no increase in donor concentration. The 0.1 at% Sn film is accordingly a good candidate to study the possible room temperature ferromagnetism when co doping with Mn. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] | ||||||||||