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Sodium bismuth titanates Na1/2Bi1/2TiO3 (NBT) doped with 0–3 wt% Er2O3 were prepared by the conventional solid-state reaction method. The X-ray diffraction results revealed that the sintered Er-doped NBT ceramics exhibited a pure perovskite structure with Er3+ concentrations ranging from 0 to 1 wt%. At a low Er2O3 concentration, the Er-doped NBT ceramics showed enhanced electrical properties with dielectric constant ℇ33T/ℇ0=636, a low dielectric dissipation factor (tan δ=3.3%), a low coercive field ( Ec=4.56 kV/mm), and a high piezoelectric constant ( d33=75 pC/N). The relationship between the composition and properties of Er-doped NBT ceramics has been discussed. [ABSTRACT FROM AUTHOR]

The properties of an aqueous Bi[sub 4]Ti[sub 3]O[sub 12] suspension stabilized b x an acrylic acid/acrylic ester copolymer have been investigated. The adsorption of a copolymer on Bi[sub 4]Ti[sub 3]O[sub 12] surface resulted in a dramatic increase in the absolute zeta potential at pH 3-11. Coincidentally, the rheological property of the suspension was significantly improved. The adsorption quantity increased with increasing copolymer concentration at first, then decreased as the copolymer concentration was beyond 1.5 wt%. The viscosity varied in a complicated manner with copolymer concentration, due to the variations in the adsorption quantity and adsorption configuration of the copolymer molecules on Bi[sub 4]Ti[sub 3]O[sub 12] particle surface. High-quality tapes were prepared through tape casting. [ABSTRACT FROM AUTHOR]

The effect of B2O3–SiO2 liquid-phase additives on the sintering, microstructure, and microwave dielectric properties of LiNb0.63Ti0.4625O3 ceramics was investigated. It was found that the sintering temperature could be lowered easily, and the densification and dielectric properties of LiNb0.63Ti0.4625O3 ceramics could be greatly improved by adding a small amount of B2O3–SiO2 solution additives. No secondary phase was observed for the ceramics with B2O3–SiO2 additives. With the addition of 0.10 wt% B2O3–SiO2, the ceramics sintered at 900°C showed favorable microwave dielectric properties with ℇr=71.7, Q× f=4950 GHz, and τf=−2.1 ppm/°C. The energy dispersive spectra analysis showed an excellent co-firing interfacial behavior between the LiNb0.63Ti0.4625O3 ceramic and the Ag electrode. It indicated that LiNb0.63Ti0.4625O3 ceramics with B2O3–SiO2 solution additives have a number of potential applications on passive integrated devices based on the low-temperature co-fired ceramics technology. [ABSTRACT FROM AUTHOR]

Upconversion emission properties of Na1/2Bi1/2TiO3:Er3+ ceramics prepared by the solid-state reaction method were analyzed as a function of Er3+ concentration and incident pump power. Strong green (550 nm) and red (670 nm) emission bands were observed with 980 nm excitation at room temperature. Experimental results showed that the emission bands can be tuned by changing Er3+ concentration. Upconversion processes in these samples result from not only a two-photon excited-state absorption process but also a nonradiative energy transfer and cross-relaxation process. [ABSTRACT FROM AUTHOR]