瓷杂 有多少精品可以关注

它们是拍场上绝对不能缺少的品种，它们也常常爆出记录，它们受到诸多藏家的关注，它们的表现时好时坏、时冷时热，今年秋天，瓷杂、油画和钱币，这三类藏家参与人数众多的收藏品种能吸引我们的眼球吗？

2006年瓷杂市场:看起来很美

2006年艺术品拍卖还未结束，各方已开始总结2006年艺术品拍卖的得与失。与往年相比，2006年的瓷杂市场显得更为热闹，更为精彩，高价位拍品层出，天价拍卖纪录一次又一次地被刷新。拍卖公司之间的竞争也越来越激烈．不仅表现在拍品的争夺上，还表现在拍卖公司的运作之上。总之，未来的瓷杂市场的拍卖越来越有看头。

季拍瓷市回暖 精品期待买家——从2006年季拍看未来瓷杂市场

2006年3月10日到19日，国内多家拍卖公司举行了四季拍中的春季小拍，其中北京的中国嘉德2006年第一期的四季拍卖会，保利的新春拍卖、翰海的迎春拍卖、荣宝第53期精品拍卖会、北京华辰第五期鉴藏拍卖会、上海东方国际的2006“金融与收藏”李可染五幅作品保真精品专场拍卖会、上海道明第一届艺术品联谊拍卖会等。此次季拍在2006年的拍卖市场中形成了一个拍卖小高潮。

ANALYSIS ON THERMAL CONDUCTIVITY OF AlN CERAMIC SUBSTRATE

The experiments and theoretical analysis on the thermal conductivity of AlN ceramic substrate are carried out.All the results prove the following viewpoints:the maximum thermal conductivity of AlN with a lower oxygen concentration is higher and the thermal conductivity decreases with the increase of oxygen concentration in AlN ceramic;Y 2O 3 acting as a sintering additive should be mixed more into the AlN powder with a lower oxygen concentration.Secondary phases affect the thermal conductivity of AlN significantly.The quantitative relationship between the thermal conductivity and oxygen,Y 2O 3 is developed.

Microstructure and electrical properties of Lu_2O_3-doped ZnO-Bi_2O_3-based varistor ceramics

Lu2O3-doped ZnO-Bi2O3-based varistor ceramics samples were prepared by a conventional mixed oxide route and sintered at temperatures in the range of 900-1 000°C,and the microstructures of the varistor ceramics samples were characterized by X-ray diffractometry(XRD)and scanning electron microscopy(SEM);at the same time,the electrical properties and V-I characteristics of the varistor ceramics samples were investigated by a DC parameter instrument for varistors.The results show that the ZnO-Bi2O3-based varistor ceramics with 0.3%Lu2O3(molar fraction)sintered at 950°C exhibit comparatively ideal comprehensive electrical properties.The XRD analysis of the samples shows the presence of ZnO,Bi-rich,spinel Zn7Sb2O12 and Lu2O3-based phases.

Phase evolution and room temperature ferroelectric and magnetic properties of Fe-doped BaTiO_3 ceramics

To make the ferroelectric BaTiO3 possess ferromagnetism simultaneously,magnetic Fe was doped into BaTiO3 ceramics at doping levels up to 10%(molar fraction).Both tetragonal and hexagonal phases coexisted in the Fe-doped BaTiO3 ceramics except at 1% doping level.X-ray diffraction analysis indicated that higher doping level of Fe,higher sintering temperature and longer sintering time promoted the formation of hexagonal phases in Fe-doped BaTiO3 ceramics.Ferroelectricity was observed in all samples at room temperature,but it was greatly depressed by Fe doping.Except at doping level of 1%,room-temperature ferromagnetism was observed in the BaTiO3 ceramics.The dependence of the saturation magnetization and coercivities of the Fe-doped BaTiO3 ceramics on doping level was systematically studied.Both the saturation magnetization and magnetic coercivities were found to be dependent on the doping level as well as the fraction of the hexagonal phase in the ceramics.

Effect of doped Mn on piezoelectric properties of (Na_(0.5)Bi_(0.5))_ (0.92)Ba_(0.08)TiO_3 lead-free ceramics

Piezoelectric ceramics (Na0.5Bi0.5) （0.92）Ba0.08TiO3 +x%MnCO3（BNBT-Mn, x=0CD*21.6, mass fraction） were synthesized by conventional solid state reaction. The results show that when the addition of MnCO3 is 0CD*2 1.4%, BNBT-Mn ceramics exhibit a single-phase perovskite structure. With the increase of content of MnCO3, piezoelectric constant and electromechanical coupling factor increase rapidly when x is lower than 0.3. Then they both decrease when x is in the range of 0.3 and 1.6. When x=0.3, piezoelectric constant and electromechanical coupling factor reach the maximum value of 160pC/N and 58.5% respectively, which can improve the temperature stability of BNBT-Mn.

Comparative characteristics of yttrium oxide and yttrium nitric acid doping in ZnO varistor ceramics

The effect of different molar ratios of Y2O3 and Y（NO3）3 on the microstructure and electrical response of ZnO-Bi203-based varistor ceramics sintered at 1 000 ℃ was investigated, and the mechanism by which this doping improves the electrical characteristics of ZnO-Bi203-based varistor ceramics was discussed. With increasing amounts of Y（NO3）3 or Y2O3 in the starting composition, Y2O3, Sb204 and Y-containing Bi-rich phase form, and the average grain size significantly decreases. The average grain size significantly decreases as the contents of rare earth compounds of Y（NO3）3 or Y2O3 increase. The maximum value of the nonlinear coefficient is found at 0.16% Y（NO3）3 or 0.02% YaO3 （molar fraction） doped varistor ceramics, and there is an increase of 122% or 35% compared with the varistor ceramics without Y（NO3）3 or Y2O3. The threshold voltage VT of Y（NO3）3 and Y2O3 reaches at 1 460 V/mm and 1 035 V/ram, respectively. The results also show that varistor sample doped with Y（NO3）3 has a remarkably more homogeneous and denser microstructure in comparison to the sample doped with Y2O3.

Structure and Dielectric Properties of Sb_2O_5-Doped ZrO_2-SnO_2-TiO_2 Microwave Ceramics

The microwave dielectric properties of ZrO2-SnO2-TiO2 （ZST） system ceramics were studied as a function of the amount of Sb2O5 dopant. With the addition of 0-0.5% Sb2O5（molar ratio）, the substitution of Ti4^＋ ions with Sb^5＋ ions decreased the sintering temperature and increased the quality factor Q due to the reduction of oxygen vacancies, When the amount of Sb^5＋ increased further （above 0.5%）, Q was decreased by increasing the electron concentration. When the system doped with 0.5% Sb2O5 was sintered at 1 150℃ for 6 h, the relative dielectric constant ε, Qf0, and the temperature coefficient of resonant frequency （TCF） were 38.46, 44 500 GHz, 20.0×10^-6/℃, respectively, at 6 GHz,

Effects of Eu_2O_3 doping on microstructural and electronic properties of ZnO Bi_2O_3-based varistor ceramics prepared by high-energy ball milling

ZnO-Bi2O3-based varistor ceramics doped with EU2O3 in a range from 0 to 0.4% were obtained by high-energy ball milling and fired at 900-1000 ℃ for 2 h. XRD and SEM were applied to determine the phases and microstructure of the varistor ceramics. A DC parameter instrument was applied to investigate the electronic properties and V-I characteristics. The XRD analysis of Eu2O3-doped ZnO-Bi2O3-based varistor ceramics shows that the ZnO, Eu-containing Bi-rich, Zn7Sb2O12-type spinel and Zn2Bi3Sb3O14-type which is the pyrochlore phase are present. With increasing Eu2O3 content, the average size of ZnO grain firstly decreases and then increases. The grain boundary defect model was particularly used to explain the excellent nonlinearity of ZnO-Bi2O3-based varistor ceramics with the addition of0.1% Eu2O3 and sintered at 950 ℃.

Structural and Dielectric Properties of Y_2O_3-Doped Ba_(0.92)Sr_(0.08)Ti_(0.95)Sn_(0.05)O_3 Ceramics

The structural and dielectric properties of Ba0.92Sr0.08Ti0.95Sn0.0503 （BSTS） ＋x（molar ratio, %） Y^3＋ceramics are investigated. Combining the lattice parameters and the distortion of crystal lattice, an alternation of substitution preference of Y^3＋ ion for the host cations in perovskite lattice is found. Owing to Y^3- ion entering the A site, the maximum dielectric constant is 5 627 for 1.25% Y^3＋-doped samples; when Y^3- ion is more than 1.25%, it tends to occupy the B site in perovskite lattice, causing a drop in the dielectric constant. Owing to the appearance of oxygen vacancy, the optimized dielectric loss is 0.004 for 1.25% Y^3＋-doped samples. The thermal stability of BSTS ceramics is significantly improved and the Curie temperature shifts to lower value with the amount of Y2O3 increased, making it a superior candidate for capacitor applications.

Effect of Laser Ablation Cleaning Process on Ceramic Artifacts

In this work, the results of a study of laser ablation cleaning process on ceramic artifacts are presented. The experiments were conducted on a ＂Carosello＂, a structural hollow element made of clay, placed in arches, in domes or even in the walls of buildings such as churches and houses. Our results show that laser ablation techniques is able to remove the surface impurity patina from artifacts surface without changes the chemical composition and the optical properties of ceramic. Moreover, because the laser cleaning heats only locally the surface of the sample, this method don＇t preclude the possibility to apply on artifact the thermo-luminescence dating process.

Low-temperature sintering and microwave dielectric properties of Li_2MgTi_3O_8 ceramics doped with BaCu(B_2O_5)

The influences of BaCu（B2O5） （BCB） addition on sintering, microstructure and microwave dielectric properties of Li2MgTi308 ceramics were investigated using X-ray diffractometry, scanning electron microscopy and microwave dielectric measurements. The experimental results show that a small amount of BaCu（B2O5） addition can effectively reduce the sintering temperature to 900℃, and induce only a limited degradation of the microwave dielectric properties. Typically, the best microwave dielectric properties of er24.5, Q×f =24 622 GHz, rf=4.2×10-6℃ -1 are obtained for 1.0% BCB-doped Li2MgTi3O8 ceramics sintered at 900℃ for 3 h. The BCB-doped Li2MgTi3O8 ceramics can be compatible with Ag electrode, which may be a strong candidate for low temperature co-fired ceramics applications.

Electromagnetic Pump Made in a Hybrid Polymer-Ceramic Technology--Preliminary Results

This paper describes technology of the electromagnetic pump made in a hybrid polymer-ceramic technology. The pumping mechanism is realized with a mutual excitation between an electromagnetic coil and a neodymium magnet bonded to a flexible membrane. A PDMS （poly（dimethylsiloxane）） material was used to manufacture a membrane sufficient for the presented micropump. A fish trap construction is adapted to the ceramic technology. The bonding process of ceramics and polymer, using plasma oxidation method, is described as well. Moreover, a membrane deflection depending on magnet dimensions and applied voltage was measured.

Preparation and Spectral Properties of Er,Na∶CaF_(2) Transparent Ceramics

Er^(3+),Na^(+)co-doped CaF_(2) transparent ceramics with Er^(3+)dopant concentration of 3% and Na^(+)of 0%,0.5%,1.0%,1.5% and 2.0% were fabricated by the vacuum hot pressing method with 16 mm in diameter and 3 mm in thickness.The average grain size of the obtained Er,Na∶CaF_(2) powders varied from 28 nm to 36 nm with the shape of sphere.The effects of Na^(+)doping on the transmittance,microstructure and spectral properties of Er^(3+)∶CaF_(2) transparent ceramics were investigated.The transmittance of all the obtained ceramic samples is above 84%in the wavelength of 1000 nm.The results show that after introducing Na^(+)into Er^(3+)∶CaF_(2) transparent ceramics,charge-neutralized Er^(3+)-Na^(+)structure formed which prevent Er^(3+)from clustering.The emission spectra of Er^(3+)in CaF_(2) transparent ceramics at around 1.5 and 2.7μm could be modulated by adjusting the concentration of Na^(+)and the near-infrared fluorescence lifetime at around 1.5μm increase with the increasing of Na^(+)concentration,reaching a maximum of 56.75 ms.

拍卖二三事

大收藏家的眼力为什么那么好? 多半也是早年扔出大把银子历练出来的。

Effects of Co doping on electronic structure and electric/magnetic properties of La_(0.1)Bi_(0.9)FeO_3 ceramics

In this work,we report the influence of Co-doping on the electronic band structure,dielectric and magnetic properties of La0.1Bi0.9Fe1-xCoxO3 ceramics.X-ray photoelectron spectroscopy investigation shows that Co dopant can shift the valence band spectrum and core-level lines of constituent elements towards higher bind energy regions simultaneously increase the concentration of oxygen vacancies in ceramics.The effects of dopant are discussed with focus given to the Co-doping induced enhancement of electrical conductivity and resistive switching phenomena.

Preparation and characterization of dense lanthanum-doped bismuth titanate ceramics

In this work, we present an effective way to increase the density of lanthanum-doped bismuth titanate ceramics （Bi4_xLaxTi3Oa2; BLT）. Dense BLT ceramics with formula Bi4LaxTi3012 （when x = 0.25, 0.5, 0.75, 1.0） are prepared by using nanocrystalline powders fabricated by the sol-gel method and high-pressure technique. The thermal decomposition and phase transformation process of the gel precursors are studied by using DTA, infrared spectroscopy （IRS） and X-ray diffraction （XRD）. The micro- structures of BLT ceramics are investigated by using transmission electron microscopy （TEM） and scanning electron microscopy （SEM）. The experimental results indicate that the phase compositions of all samples with various La substitutes at 900℃possess the layer-structure of Bi4Ti3012 （BTO）. The green pellets are pressed under 2.5, 3.0, 3.5 and 4.0 GPa, separately. It is found that the density of BLT ceramics is significantly increased due to the decreasing of porosity in the green compacts by the high-pressure process. The samples are sintered at temperatures between 900 and 1100℃and it is found that the optimum sin- tering temperature is 1100℃. Dense BLT ceramics with 90% of their theoretic density have been achieved from the sample prepared at a sintering temperature of 1100℃ for 1.5 h.