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Multiple direction compression (MDC) was conducted on sintered pure tungsten (99.9%, mass fraction) with different reductions at 1423 K. The microstructure, microhardness and thermal stability of the MDC-processed samples were studied by X-ray diffraction (XRD), electron backscattered diffraction (EBSD) and differential scanning calorimetry (DSC) compared with those of the initial sintered tungsten. The results show that the dislocation density increases significantly with the reduction of MDC, ranging from 3.08×1014 m–2 for the initial sintered tungsten to 8.08×1014 m–2 for the tungsten after MDC with the reduction of 50%. The average grain size decreases from 83.8 to 14.7 μm and the microhardness value increases from HV0.2 417 to HV0.2 521. The recrystallization temperature for the tungsten samples processed by MDC is approximately constant at around 1600 K. The MDC of sintered tungsten results in a decrease of grain size concurrent with an increase of uniformly distributed nucleation sites, which leads to the improvement of the thermal stability.

Lead-free EO ceramics have been received increasing attentions from the view point of green environment in recent years. In this study, lead-free Ba6-1.5xLaxTi2Nb8O30 (0≤x≤7%) ceramics were synthesized by the conventional solid state reaction sintering method. The effects of lanthanum doping on the microstructure and electrical properties of Ba6Ti2Nb8O30 (BTN) ceramics were investigated and analyzed. The XRD results revealed that the lanthanum doping changed the BTN lattice parameters slightly. The sample grain size, dielectric constants (1kHz) and the temperature Tm gradually decreased with the increasing of lanthanum doped content. The optimized BLTN ceramic sample with x=4 mol % exhibited a good transparency and excellent electrical properties (Ps=6.41 μC/cm2, Pr=0.77 μC/cm2, and Ec=3.80 kV/cm).

The lanthanum-modified lead zirconate titanate transparent ceramics with different Zr/Ti ratio were prepared by the hot pressing sintering method. A single perovskive structure with a dense microsctructure was obtained and the transgranular fracture of PLZT ceramics tended to be more serious As the Zr/Ti ratio increases, the transmittance of PLZT ceramics tended to be higher and the transgranular fracture became more serious. The P-E loops changed froe a square hysteresis loop to a double tending slim hysteresis loop. Besides,the S-E loops changed from a approximate parabolic shape to a butterfly shape. These two loops confirm the transition from normal ferroelectric to anti ferroelectric phase occured with the Zr/Ti ratio increasing.

Aurivillius phase ferroelectrics Ba(Bi1−xLax)4Ti4O15(x=0-0.05) (BBiLxT) was synthesized by a modified high-temperature solid-phase route.The structure, the dielectric, the ferroelectric and the aging properties were investigated systematically. With the La3+doping, the room temperature relative permittivity of the samples is increased, and dielectric loss is decreased. For the BBiLxT phase, only a weak variation with respect to the F2mm space group can be suggested from single crystal X-ray diffraction. The microstructure confirms the samples have a well-proportioned grain size and a higher density. The substitution also results in a marked improvement in the remnant polarization. The doping of La3+in BBiLxT ceramics increased the room temperature relative permittivity aging properties.

BaBi2Nb2O9/PVDF (polyvinylidene fluoride) composite ultrafiltration (UF)membranes were prepared by alloying BaBi2Nb2O9 (BBN) particles uniformly in the PVDF solution (15% polymer weight) and used a phase-inversion method. This paper studied the effect of the concentration of BBN from 0% to 5% in 0.2Mpa on pure water flux and rejection rate to Bovine serum albumin (BSA). The cross-sectional structures of composite membranes were observed by scanning electron microscopy (SEM). Moreover, XRD results revealed the crystal structure of PVDF. The experimental results showed that the BBN/PVDF composite ultrafiltration membranes were superior in separation performances than the pure PVDF membranes due to the addition of BBN.

Currently, Yttria-stabilized zirconia solid state electrolyte are widely used in various fields . The basic performance of Yttria-stabilized zirconia (5YSZ) prepared by different synthesis methods and sintering temperatures are studied in this paper ,their phase compositions and microstructure are studied with XRD and SEM. The ionic conductivity of 5YSZ sintered at different temperature are studied with A.C. impedance spectroscopy measurement.

3Y-TZP powder has been successfully synthesized by gel solid-state method. The structural phases of powder particles were analyzed by X-ray diffraction and the morphology was analyzed by scanning electron microscopy. The average size of grains was 230 nm. The sintering behavior, mechanical properties and microstructure of 3Y-TZP ceramics sintered by this powder were investigated. The experiment results showed that the mechanical properties of ceramics were excellent.

La3+ doped textured ceramics CaBi4-xLaxTi4O15were prepared by oriented consolidation of anisometric particle method with tape casting. The orientation was improved by modifying sintering temperature. The doping of La3+in orientated CaBi4-xLaxTi4O15ceramics increased the dielectric constant. The higher dielectric constant was obtained in the direction which tropism parallels to the electric field. The relationship between dielectric constant and orientation was discussed.

The influence of conductivity of supernatant of 3Y-TZP powder on the sintering properties of its ceramics is evaluated. It is found that the conductivity of supernatant is helpful for the determination of the sintering activities. The sintering properties of 3Y-TZP ceramics are improved with the increase of the conductivity of supernatant. It is attributed to a large amount of unsaturated states in the powder.

Ferroelectric BaTiO3/polyvinylidene fluoride (BaTiO3/PVDF) composites were prepared by a coating technique. It was observed that BaTiO3powders prepared with different thermal treatment temperatures affected dielectric performances of the composites. The polymer with fine BaTiO3powder exhibited a lower dielectric loss than that with coarse powder. Fourier transform infrared spectrum was carried out to investigate the vibration of chemical bonds. The relationship between the dielectric property and intercoupling between F-ion and oxygen octahedron was discussed.

(200) grain-oriented 0.91Pb(Zn1/3Nb2/3)O3–0.09PbTiO3 (PMN–0.09PT) piezoelectric ceramics with a degree of orientation of 0.5052 have been produced from melt by a directional solidification method. The dielectric, ferroelectric, and piezoelectric properties were investigated, e.g., ε~4200, tanδ~0.8%, d33~2100pC/N, kt~58%, and k33~90%, some of these values are comparable to those of ~PZN–PT single crystals. The strain–electric-field curve with a maximum strain of 0.49% at a field of 7kV/cm and well-saturated hysteresis loops with a Pr~32 mC/cm2 were recorded. The results demonstrate that the directional solidification method is a promising technique to fabricate high performance grain-oriented PZN–PT ceramics.

A new process was developed for fabrication of multiferroic 1-3 type nanostructured composite films. In this process, eletrodeposition method was adopted to prepare the arrays of cobalt nanowires as ferromagnetic composition. The images, phase structure and magnetic properties were characterized by SEM, XRD and VSM, respectively. The results showed that applying magnetic field during electrodepostion process could improve the alignment and height uniformity of nanowires arrays, inducing (002)-orientation growth. The PZT (53/47) precursor solution prepared for ferroelectric composition was infiltrated the spaces between nanowires. After annealed at 700 °C for 20 min, the 1-3 type multiferroic composite film was achieved. Preliminary results show this technique to have the potential to become a practical fabrication process for 1-3 type multiferroic composite films.

Ba0.6Sr0.4TiO3 materials doped with boron family Al3+, Ga3+ and In3+ are prepared by a ceramic process. The specimens possess condense microstructures. A low dielectric loss is achieved in the sample doped with In3+. Dielectric constants increase with decrease of the radii of doped ions. The results are discussed with respect to the interaction between oxygen ions and ions at B-site in ABO3 perovskite, which is revealed by Fourier transform infrared spectrum.

High purity BaTiO3 single crystal was aged below its Curie temperature for different times. The reverse transformation (from tetragonal to cubic) temperature was measured precisely by differential scanning calorimetry (DSC). It was observed that the reverse transformation temperature increased with increasing aging time, indicating ferroelectric phase became stable with aging. This behavior is the same as found in ferroelastic alloys. The origin of the stabilization effect in ferroelectric single crystals was discussed with respect to the distribution of point defects.

Microstructure and dielectric properties of relaxor ferroelectrics in the solid solution, formulated 0.67Pb(Mg1/3Nb2/3)O3–0.33PbTiO3 + 2 mol% RE (RE = Sm, Nd, Yb or Ce), have been investigated. The effects of these dopants on microstructure, maximum dielectric constant (Kmax) and degree of ordering, etc. have been studied. It was found that doping of Sm, Nd and Ce reduced Kmax from 23924 to 14921, 13466 and 12511 respectively, while the doping of Yb increased Kmax to 27759. The variation of Kmax is analyzed according to grain size, domain structure and order–disorder behavior. Diffuseness of the phase transition is calculated to indicate order–disorder behavior, which is roughly opposite to that of Kmax. The present results show that order–disorder behavior is the key factor on Kmax of PMN–PT ceramics near morphotropic phase boundary.

Ferroelectrics 0.67Pb (Mg1/3Nb2/3)O3–0.33PbTiO3 (PMN–PT) + x mol% WO3 (x=0.1, 0.5, 1, 2) were prepared by columbite precursor method. Electrical properties of WO3-modified ferroelectrics were investigated. X-ray diffraction (XRD) was used to identify crystal structure, and pyrochlore phase were observed in 0.67Pb (Mg1/3Nb2/3)O3–0.33PbTiO3+2 mol% WO3. Dielectric peak temperature decreased with WO3 doping, indicating that W6+ incorporated into PMN–PT lattice. Lattice constant, pyrochlore phase and grain size contribute to the variation of Kmax. Both piezoelectric constant (d33) and electromechanical coupling factors (kp) were enhanced by doping 0.1 mol% WO3, which results from the introduction of “soft” characteristics into PMN–PT, while further WO3 addition was detrimental. We consider that the two factors, introduction of “soft” characteristics and the formation of pyrochlore phase, appear to act together to cause the variation of piezoelectric properties of 0.67PMN–0.33PT ceramics doping with WO3.

0.67Pb(Mg 1/3 Nb 2/3 )O 3 (PMN)–0.33PbTiO 3 (PT) ferroelectric ceramics has been selected as base component. Different content of B-site substitute (0.1, 0.5 and 1 mol%) were used to modify the base component. The specimens were synthesized by the columbite precursor method, and pure perovskite phase were obtained for all the specimens. The dielectric behavior was examined to investigate the relaxor behavior of each component. It is found that the specimen undoped and modified with 0.1 mol% WO 3 nearly behave as normal ferroelectric ceramics, while with the content of WO 3 increasing, the degree of relaxor behavior for the composition increases. Thus, B-site substitute WO 3 has a strong effect of inducing relaxor behavior of PMN–PT ferroelectric ceramics near morphotropic phase boundary (MPB).

(Na0.535K0.48) NbO3 ceramics doped with Bi2O3•Fe2O3 are prepared by a ceramic process. The effect of Bi3+ and Fe3+ on microstructure and electrical properties of ceramics is investigated. X-ray diffraction shows that the structure of the material is perovskite. The conductivity of ceramics increases with the doping content. UV-Visual absorption spectrum is affected by doping Bi3+ and Fe3+. The mechanism of conductivity is discussed with respect to energy of band-gap in the system.

The electromechanical coupling factors kt and kp in Pb(Hf y (Zr1-xTi x )1-y)O3 (PHZT) ceramic material near ferroelectric (F)—antiferroelectric (AF) phase boundary were measured. The values of kt and kp in the system are 0.46 and 0.21, respectively. The experimental results indicate that the F-AF phase boundary performs an important role in electromechanical coupling behavior in PZT based piezoelectric ceramic materials in consideration of a similar phenomenon in PZT, PSZT and PLZT systems near the F-AF phase boundary. The influence of sintering time on the coupling factor kt in PLZT ceramics was investigated. The value of kt was 0.52 in the sample that was sintered at 1320°C for 180 minutes when it was only 0.47 in the sample sintered at the same temperature for 90 minutes. The situation of grain growth in the samples was observed by SEM. It is important to control the process for preparing the ceramics with excellent electromechanical coupling performance.

The first paper1 which was presented on ISAF 90 reported the high Kt performance of the PZT ceramics with the compositions situated near the ferroelectric (F) and antiferroelectric (AF) phase boundary. In this paper, other two systems PSZT and PLZT ceramics also on F-AF phase boundary were studied and the same character which shows the high Kt for the composition situated near the phase boundary has been examined. The highest Kt is up to 0, 56. In case of favorable poling condition and additives, even higher value of Kt can be expected. The possible reasons for this character are discussed.

The PZT 95/5 thin film was prepared on Pt/Ti/ SiO2Si substrate by sol-gel method. The behavior of FRL-FRH phase transition was investigated in the thin film. The change of the remanent spontaneous polarization during the FRL-FRH phase transition is 0.6 μc/cm2.