Relaxor Pb Research Articles

Molten salt synthesis of lead-based relaxors

The molten salt synthesis (MSS) of lead-based relaxors which have a perovskite structure, A(BIBII)O3 where BI is Mg2+, Fe3+, Zn2+, Ni2+ or Co2+, and BII is Nb5+, has been reviewed with regard to the formation of the perovskites, phase stability and morphology characteristics. Two relaxor materials, Pb(Mg1/3Nb2/3)O3 and Pb(Fe1/2Nb1/2)O3 were found to be successfully synthesized at a low temperature in a very short time by the MSS method. Using the example of Pb(Mg1/3Nb2/3)O3, the phase stability has been discussed on the basis of thermal and chemical analyses. The influences of the processing parameters, such as temperature, time, type and amount of salt, and non-stoichiometry, on the formation and the powder characteristics of the perovskite phase were investigated with possible explanations for the observed differences which were induced by changing the parameters. Finally, densification behaviour and dielectric properties resulting from the MSS powder were examined and compared to those of powders obtained by using the conventional mixed oxides (CMO) method. © 1998 Kluwer Academic Publishers

Preparation and properties of Pb(Mg1/3, Nb2/3)O3-PbTiO3 thin films by sol-gel method

Ferroelectric relaxor Pb(Mg1/3, Nb2/3)O3-PbTiO3 (PMN-PT) thin films were prepared from molecular-designed alkoxides precursor solutions using dip-coating method. This study focused on the seeding effect of the formation process on the resulting perovskite PMN-PT thin films.

Properties of YBa2Cu3O7—δ–Pb(Sc0.5Ta0.5O3 Superconducting Composites

Microwave absorption of the superconductor YBa2Cu3O7—δ–ferroelectric relaxor Pb(Sc0.5Ta0.5)O3 composite of (0.5/0.5) composition in weight was studied. The composite exhibits a critical temperature enhancement up to Tc-onset = 95 K clearly visible both in the transport and microwave absorption measurements. The structural investigations indicate the unchanged structure of YBa2Cu3O7—δ. The studies of magnetic field-dependent microwave absorption show a presence of intergrain weak links. The first intergrain penetration critical field Hc1J = 4 Oe. Both the inter- and intragrain penetration regimes can be observed.

Sol-gel derived Pb(Sc 0.5Ta 0.5)O 3 powders

Phase pure ferroelectric relaxor Pb(Sc 0.5Ta 0.5)O 3 perovskite (PST) has been synthesized using metal organic precursors including Pb(CH 3COO) 2 · 3H 2O, Sc(CH 3COO) 3 · xH 2O and Ta(OC 2H 5) 5. This method of synthesizing PST powders yields phase pure PST and the present route via organic precursors is much simpler in contrast to the earlier reported approaches.

The Fast Firing of the Ferroelectric Relaxor Pb(Mn1/3Nb2/3).02 (Mg1/2 W1/2 ).48 Zr.23 Ti.27O3

AbstractThe possibility of fast firing a relaxor dielectric to suppress grain growth, mitigate the lead loss and reduce the cost of sintering has been investigated. The relaxor Pb(Mn1/3 Nb2/3).02 (Mg1/2 W1/2 ).48 Zr.23 Ti.27 O3 [1] exhibits a highly desirable broad phase transistion range when the prbcessing procedures are carefully controlled and fired conventionally. When fast fired, this material's density, percentage of secondary phases, and dielectric constant were highly dependent on the sintering time. A sample fired for 6 minutes possessed a dielectric constant nearly equal to the same material conventionally fired for 16 hours.