The present paper reviews the recent progress in studies on fabrication and dielectric piezoelectric and electrostrictive properties
of relaxor ferroelectric PZNT. The dominant method of fabrication of PZNT is the PbO flux method at high temperature, by which the single
crystals with size of 40mm have been grown. Studies on their dielectric properties indicated that the behavior of phase transition of PZNT crystals
would vary from diffused, mixed to first order transition type with the increase of PT concentration. The rhombohedral-tetragonal ferroelectric
phase transition is also diffused which can be induced by composition or electric field. Single crystals with their composition at MPB or in the
rhombohedral phase region near MPB have extremely strong piezoelectric properties. The <001> oriented rhombohedral and tetragonal crystals
are respectively suitable for acoustic arrays and single element sensors and actuators with broader bandwidth, improved sensitivity and optimum
impedance matching. Crystallographically, high strains are achieved for <001> oriented rhombohedral crystals and their levels reach an order of
magnitude of those available from conventional piezoelectric and electrostrictive ceramics such as PZT series and PMNT ceramics, which make these crystals
as promising candidates for high performance solid actuators.

A large size PbF₂ crystal was grown with the modified non-vacuum Bridgeman method. Itpossesses outstanding Cherenkov radiation properties. Its cut-off edge is as short as 245urn, theenergy resolution is superior to 3.2%/E^1/2, and the radiation damage is weak and can be cured byannealing with 365um filtered light.

The glass-forming region of GeS₂-Ga₂
S₃-KBr system glass was determined. The homogeneous glass containing KBr and
Ga₂S₃ up to 25mol% was prepared. The minimum content of GeS₂ for glass formation is 50mol%. Glass dehydration temperature
T_w, thermal expansion coefficient, ionic conductivity, optical transmission spectra and chemical durability of GeS₂-Ga₂S₃-KBr system glass were investigated. The experimental
results show that the highest characteristic temperatures of the glass are T_w>284.7℃, T_d=355℃, T_c=593℃ and ΔT=T_c-T_w>200℃. The optical
transmission of the glass is between 0.45 and 11.5μm. The transparent region of the glass shifts towards ultraviolet region by adding KBr. The
absorption bands at 3600, 2500 and 1600cm^-1 in infrared spectra can be assigned to the stretching vibration of O--H groups, the stretching
vibration of S-H groups and the bending vibration of H--O--H groups. The ionic conductivities of the glass are 10^-9～10^-12S/cm at 23℃,
10^-4～10^-6S/cm at 270℃. The chemical durability of GeS₂-Ga₂S₃-KBr system glass is satisfactory. The glass of GeS₂-Ga₂S₃-KBr system could be used as a potential candidate optical material
transmitting from visible to mid-infrared regions.

The aim of this study was to produce an infrared transmitting material with multiphonon absorption edge longer than 20μm.
For this purpose, chalcohalide glasses based on As₂Se₃-AsTe-CuI system were studied. The glass forming region was obtained and
homogeneous glass prepared. Binary system glass may be formed by combining As₂Se₃ with AsTe in any proportion, the maximum content
of CuI in As₂Se₃ is up to 70 mol% and that of CuI in AsTe about 45 mol%. These glasses have a good glass forming ability and it is easy
to obtain the samples of diameter about 20mm and thickness over 50mm. The far infrared spectra of the glasses were investigated. The results
demonstrate that basic structural units are [As(SeTe)_3-xI_x(x=0～3), As₂Te₄] and [CuI_4], their proportions depend on the
composition of the glasses. With the help of experimental results and theoretical analysis, a structural model of glasses was suggested.

Titanium dioxide ultrafine powders were prepard by sol-gel and supercritical fluid drying(SCFD) methods from cheap inorganic salts as raw materials. The ultrafine powders were characterized in terms of XRD, DTA-TG and TEM techniques. The dependence of particle size onsolution PH value, concentration, ageing time and SCFD condition was also investigated. It wasfound that the ultrafine powders so obtained eXhibit small crystallite sizes of 3-6urn, better thermal stability and less weight loss.

The influences of chemical composition and fabrication technology of forming powders on sintering density, Na-ion conductivity
and microstructure of β’’-Al₂O₃ ceramics were investigated. Compared with water-based slurry, ethanol-based slurry was more stable
and could be prepared more easily. Moreover, the latter had better stability to moisture and chemical homogeneity, and the agglomerates
could be crushed at a lower pressure. Thus, higher green densities could be obtained. High quality β’’-Al₂O₃ ceramics with densities
>3.23g·cm^-3, and resistivities of 5～6Ω·cm at 300℃　and homogeneous microstructures were　prepared with such powder spray dried from ethanol-based
slurry which was composed of two components, namely Li₂O-Al₂O₃ and Na₂O-Al₂O₃ calcinated at 1250℃ for 2h. respectively. The
contents of Li₂O and Na₂O in the resulting powders were variable in the ranges of 0.69～0.75wt% and 8.85～9.10wt%.

ZrO₂(3Y) precursor was prepared via hydrous-zirconia which was Y(OH)₃-coated preparedby microwave heating coated with Y(OH)₃. The surfaCes of Al₂O₃, nanometer SiC and Y(OH)₃ coated hydrous-zirconia particles were modified with PMAA-NH₄, so that three kinds of periclesin aqueous suspensions had the same charge and highly dispersed state at pH=9.0. Finally, ahighly dispersed and uniformly mixed suspension of Al₂O₃-SiC-ZrO₂(3Y) precursor was obtainedfrom miting three kinds of single suspension.

The Ti-doped mesoporous silica MCM-41 materials were synthesized under basic conditionat room temperature. The characteristics of samples were investigsted by using XRD, HREM, IR,and N₂ adsorption techniques. The results show that Ti ions can get into the St frame work andlead to the vibration of St-O-Ti bond, with the increase of Ti ion addition, the mesoporous silicaframework structure can be disordered and finally deteriorated.

Heterogeneous precipitation methods were used to produce 5 vol% SiC-Al₂O₃ nanocomposite powder, from aqueous suspension of Nano-SiC (70 nm), aqueous Solution of aluminium chloride and ammonia. The SiC-Al₂O₃ nanocomposites
were superfast densified by spark plasma sintering (SPS) process with heating to a sintering temperature range from 1350 to 1550℃, at a
heating rate of 600℃/min, without holding time, and then fast cooling to 600℃ within 2～3 minutes; and high density nanocomposites
were obtained. The expermental results show that bending stregth of 5 vol% SiC-Al₂O₃ nanocomposites sintered at 1450℃ is as high as 1000 MPa,
while vickers hardness about 19 GPa. Fracture toughness of the sample sintered at 1500 ℃ is about 4 MPa·m^1/2, a little bit higher than
that of Al₂O₃ ceramics. Microstructure studies show that nano-SiC particles are mainly located in Al₂O₃ grains and the fracture mode of the nanocomposites
is mainly transgranular fracture. Due to the expansion coefficient mismatch and most of SiC particles located in Al₂O₃ gains, the tensile stress, which
weakens matrix grains and originates the transgranular fracture, will appear when the samples cool down from the sintering temperature.

Si₃N₄, TiC and SiC whisker reinforced SiC matrix composites were Hot Isostatically Pressed, and the microstructure and mechanical
properties were studied. The strengthening and toughening mechanisms are different depending on the incorporation of second phase. Si₃N₄ in
the matrix may induce the radius compressive force because of the difference of thermal expansion coefficient and elastic modulus. As
a result, the crack propagation will be hindered. TiC in the matrix will induce the radius tension force so that the crack will be deflected.
The incorporation of SiC_W can produce the composed strengthening and toughening mechanism such as crack deflection, pull out, so that both
of the strength and fracture toughness will be improved.

A novel sol-gel particle-coating technique was developed to form a thin glassy layer on the surface of PZN particles. Two types of
powders with different Curie temperatures were used as high-temperature constituent and low-temperature one to prepare PZN-based composite ceramics.
A PZN-based diphasic ceramic with X7R character and high dielectric constant was successfully obtained at low sintering temperature.
The results show that the particle-coating method is effective to lower sintering temperature of the composite ceramics and suppress the reaction
between the two starting constituents.

The sintering below 900"C of NiCuZn ferrite was realized by using Bi₂O₃ additions. Themechanism of low-temperature sintering was discussed by means of TG,DTA and DDTA. The resultshows the optimum sintering temperature range is 850~ 900℃ and a second phase, Bi₃₆Fe₂O₅₇ formed. The solution of Fe is helpful in both stabilizing cubic structure of r-Bi₂O₃ and keepingaway from crystal transition during cooling. Bi₃₆Fe₂O₅₇ prevents grain growth effectively, so thatthe modification of NiCuZn ferrite can be achieved.

The effect of Al additions on the microstructure of hot pressed MoSi₂ was studied, and the concept of transition-gas-phase-sintering was proposed. The results indicate
that the SiO₂ phase on grain boundary is eliminated by the reaction of Al and SiO₂ while the Al₂O₃ particles are produced, and
the MoSi₂ lattice is changed because of the diffusion of Al atoms. Furthermore, the sintering is advanced because of the deformation of
MoSi₂ lattice and the disappearance of residual gas which is replaced by Al vapor in isolated pores, so porosity is reduced. The porosity
is the lowest when Al additive is 3.5 wt%.

The application of microemulsion made of anion surfactants in preparing SnO₂ naosized materials was studied, and the influence of different anion surfactants and assistant
surfactants on the mean grain size of nanosized SnO₂ was also researched by XRD and TEM. It can be known from the experimental results, monodispersed SnO₂ nanosized materials with the
mean grain size of about 6nm and average partical size smaller than 20nm can be obtained from the microemulsion composed of AES or K₁₂ anion surfactant and butanol assistant surfactant, and it
has high sensitivity without catalysts and additives.

The interlayered cross-linking of a 2:1 type montmorillonites with a hydroxy-polymers Al wasstudied by means of XRD and IR. The formation conditions and preparation process of porousclay were also dealt with. The results show that the preparation conditions such as concentrationsof cross-linking agent, reaction temperatures and washing greatly effect the formation of porousclay. The dilute solution of cross-linking agent is beneficial to the formation of porous clay; andthe process of cross-linking is reversible

The pillared montmorillonite was prepared by Al³⁺ in Keggin ions which has Keggin structure.²⁷Al NMR was used to monitor the environment of Al³⁺ in solution. The thermal stability ofpillared clays was determined by XRD, IR, DTA, TG and AFM. The results suggest when m=2.4 the quantity of Keggin ions in AlCl3 solution is more. In natural state, the d(001) value of pillaredmontmorillonite is 2.53urn, after calcined at 300℃, the hasal interlayer spacing is stabilized 1.83um,with high stability.

The Ba_xSr_1-xTiO₃ (BST) materials of various compositions (x=0.75,0.70,0.60) were prepared by sol-gel processing.
The reaction mechanism was investigated by FT-IR technique. The thermolysis process of the BST-gel was analyzed by DTA and XRD. The dependence of Curie point on compositions
and the properties of the IR detection for the BST sample under dc bias were also studied. The results showed that the synthetic
temperature of BST powder is 930℃, which is much lower than that by the conventional solid-state reaction method, the BST powder
obtained has a narrow distribution. The sintering temperature falls from 1380℃ to 1320℃, the overgrowth of the grain is constrained
and the average grain size is ～5μm. The relative permittivity of the BST sample increases by 20% over that by the conventional
processing, the minimum dissipation factor measured is 0.0025, and the pyroelectric coefficient reaches at 20×10^-8C/cm²·K.

PZT thin films were fabricated on (111)Pt/Ti/SiO₂/Si by RF magnetron sputtering with a ceramic target(PZT53/47). The as-deposited
thin films were annealed with a rapid thermal annealing process. XRD was used to determine the structure of the thin films. This paper focused on the
research about the influence of sputtering gas and substrate temperature on the structure of the thin films. It was found that the process of phase
transformation of PZT thin films changed with the ratio of Ar to O₂ and substrate temperatures. The ferroelectric property of PZT thin films
was measured by RT66A standardized ferroelectric test system. When 5V voltage was applied, the film showed a remnant polarization of 14.6μC/cm², and coercive
field of 82.9kV/cm.

Non-equilibrium stationary phase diagrams for diamond growth with nitrogen addition into the reaction system were calculated and coordinate
well with published experimental results. Therefore they can direct the experimental research on the subject. The effects of nitrogen addition on
the deposition of diamond films were discussed by using the phase diagrams. The nitrogen addition can accelerate the deposition rate of diamond films
in two aspects: enhance the CH₃ concentration at the growth surface and accelerate the abstraction of H atoms covered the growth surface sites.

PZT thin films were prepared by metallo-organic decomposition(MOD). Phase transformation from pyrochlore to perovskite was studied by XRD and TEM.
XRD analysis showed that pyrochlore phase transformes into perovskite phase fully above 600℃for the PZT thin films on Pt/Ti/SiO₂/Si
substrates. However, TEM results indicated, for the free-standing PZT thin films on Pt foil with many microholes, that the transforming
temperature from pyrochlore to perovskite is much higher, and the temperature is related to the thickness of thin films. The surface
states of MOD derived PZT thin films were investigated by X-ray photoelectron spectroscopy(XPS) with whole and narrow scanning
measurement. The results showed that there are chemical-absorbed oxygen and contamination of carbon in the film surfaces which came
from sample handling or pumping oil. Other impurity could not be detected. The films have a little Pb-rich in the surface and a
stoichiometry of Zr/Ti ratio. However, the crystal lattice of the thin film is oxygen-deficiency.

Boron carbide coatings were deposited under atmospheric pressure by plasma spray at different spraying distance. Their microstructure
and phase composition were studied through EPMA, EDS and XPS. Their dc conductivity was measured by standard four-probe. The results show that
the suitable spraying distance causes dense B₄C coating; the longer the spraying distance, the serious oxidation of B₄C powder is,
the spraying distance may severely affect the phase composition. The plasma spray boron carbide coatings possess semiconductor properies. The
conductivity increases with temperature. The phase composition and B/C ratio determined by the spraying distance, can affect the conductivity of boron carbide coating.

Titania-silica thin films were prepared by a Sol-gel method. The etched ability of the thin films in dilute HF solution was studied. The
film heat-treated at 800℃, reduced etch rate by a factor of almost 1000 compared with that of the film heat-treated at 200℃.
The large difference between the etch rates of densified and undensified films can be used to produce channel waveguide structures by laser scanning on the films. The difference
of the etch rates can be explained by XRD and FT-IR spectrum, and micro Raman spectrum reveals that the crystallization in the region of
laser scanning has a normal distribution.

The thermal shock failure life of thermal barrier coatings (TBCs) was studied. A mathematical model of thermal shock failure and
theoretical calculation formula of the coatings’ thermal shock failure life were established. It is shown that the thermal shock failure mechanism of
coatings is thermal stress fatigue destruction and that the formula accords well with the test results. The critical temperature range Δ T_c
in thermal schok can be used to evaluate the coating’s resistance to thermal cycling. This work provides a theoretical basis for evaluating
the coating’s lifetime and reducing test work.

The microstructure and compositions of the spots on the blue colours of Jingdezhen Blue andWhite porcelain were investigated. The spots on the blue colours of Blue and White porcelainare the result of crystallization and enrichment of manganese and iron contained in cobalt bluepigment after high temperature sintering, and the compositions of the spots mainly depend on thecontents of manganese and iron in cobalt blue pigment.

Nano-scale Y₂O₃:Eu³⁺ powders(the grain size about 20nm) were prepared by the polyacrylamide gel method. After being dealed with coating by dipping in the solutions of KAl(SO₄)₂ andNaZSiO³, nano-scale Y₂O₃:Eu³⁺ powders were covered by an composit oxide layer about 2nm.The obvious effects of coating process on the dispersity and appearance structure of nano-scaleY₂O₃:Eu³⁺ powders were found.

A magnetic-field applied to high temperature optical in situ observation (M in situ observation) technique was established in
the authors’ laboratory. An electromagnet was used as a magnetic field generator. This magnet was designed to supply up to 0.14T transversely to the center
of the heater.
By using M in situ observation technique, the relative extent of boundary layer can be reduced and the buoyancy driven convection can also be damped.
The effect of the magnetic-field upon oxide crystal growth was verified tentatively.

A novel method which involved the heating of a ZrOCl₂ and Y(NO₃)₃ solution with an alcohol-water mixture as a solvent was used to synthesize the
nanoparticles of ZrO₂(3Y). By choosing the composition of the solvent mixture and adding appropriate dispersant, weakly agglomerated powders of ZrO₂(3Y)
with the average particle size of 11～15nm can be obtained. Contrast with the ordinary trend of the powder synthesized by coprecipitation, the monoclinic
phase in this powder decreases when the calcination temperature rising from 600℃ to 900℃, the mechanism of this phenomenon was investigated.
High-density and fine-particle Y-TZP ceramics were obtained by pressureless sintering.

The authors dealt with the compaction data of ZrO₂ (3wt% Y₂O₃) nanocrystalline powders preparated by tubular reactor. The results indicate that
the compaction law of these powders conforms to Huang Peiyun Double Logarithmic Equation. According to the equation, the compaction performance
parameters of the powders calculated are the compaction module of 11.9MPa to 12.7MPa and the nonlinear exponent of 7.15. The compaction
module of the powder is decreased with increasing of binder, and the nonlinear exponent keeps almost unalterble. By combining with testing the ZrO₂
green compact pore size, analyses indicate that the ideal compacting pressure of the nanocrystalline ZrO₂ powders is from 40MPa to 140MPa, and
thus the theoretical criterion for selection the compacting pressure of the nanocrystalline ZrO₂ powders can be provided.

Nano-titania was prepared by Ti(OC₄Hg)₄ hydrolysis precipition approach, its particle sizeand agglomeration can be controlled by adjusting some parameters of the process. Reflect spectrarevealed that the series limit of nano-titania was influenced by its particle size and crystal structureas well. Titania compact with a grain size about 200um and 93.3% relative density was obtainedvia hot-pressure sintering.

The paper studied low-temperature sintering of Y-Li-Ca-Doped anti-hydrolysis AlN powders synthesized by SHS method. It is found that
Y-Li-Ca additive systems are beneficial for low-temperature sintering of AlN ceramics. AlN samples with density of 3.29g/cm³ and thermal
conductivity of 97 W/m·K were obtained after sintering at 1675℃ for 6 h with the additions of 5wt% YLiO₂ and 0.5wt% CaF₂.
The work also indicates that YLiO₂-CaF₂ is better for low-temperature sintering of AlN than YLiO₂-CaCO₃ under the same sintering conditions.

After thermal annealing, dielectric and piezoelectric properties of lead-based ferroelectric ceramics increase apparently. In PMN-PT system, E=37200, k_p=66% d₃₃=530pC/N were obtained;in PZN-PT-BT system, m=29000, k_p=51% d₃₃ =624pC/N were obtained. Thermal annealing isa good way to improve the dielectric and piezoelectric properties of lead-based ferroelectric ceramics, and this effect can be attributed to the grain boundary layer and domain wall motion in thesematerials.

Ca-α-Sialon was synthesized by hot-pressing technique, and the reaction sequences and densification of Ca-α-Sialon vs
sintering temperature were studied. It was found that Ca-α-Sialon is stable. At 1250℃ the reactant mixture started to soften, and at 1300℃ gehlenite was produced
in the system; and at 1500℃ gehlenite was resolved into liquid phase and at the same time Ca-α-Sialon formed; and at 1600℃ the reaction of formation of Ca-α-Sialon
was finished and single phase Ca-α-Sialon was got. Accompanied by the above sequences, the densification was finished by liquid
sintering through particle rearrangement, solution-reprecipitation, grain growth。

An amorphous boron-carbon-nitrogen film was synthesized by plasma source ion nitriding, that is nitrogen ion implantation at low energy (1～3 keV) and superhigh dose
(10¹⁹～10²⁰ ions·cm^-2) and simultaneously indiffusion. Auger electron spectroscopy and diffuse reflectance Fourier transform
infrared spectra showed that the films are mainly composed of sp² and sp³ plain (graphite- and pyridine-like) microdomains
with a fixed B/C ratio and a controllable nitrogen content at a nitriding temperature of 500℃ for a nitriding time from 2 to 6 h. The formation of sp³ plain microdomains strongly depends
on the nitriding temperature and softly on the nitriding time.