Aqueous tape casting of the 0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 ceramic films: Production optimization and properties

Abstract

The 0.7Pb(Mg 1/3 Nb 2/3 )O 3 -0.3PbTiO 3 ceramic films were prepared using the water-based tape casting method. Two main components of the slurry are water and solids. The concentrations of other chemicals, the surfactant and binder, are at the level of 1 wt. %. Both binder and surfactant are eco-friendly polymers. Additional chemicals are not required. The optimal concentration of surfactant determined through viscosity measurements. The density of the ceramics was studied as a function of the concentration of water and binder. The density is nearly independent of amount of water despite a wide range of values of concentration. This independence is a powerful tool to cast using different techniques. The density substantially depends only on binder concentration. The polymers removal protocol of the cast films was optimized using thermogravimetric analysis. As a result, the translucent ceramic films with a relative density of 98 % and thickness of 70 µm were prepared. The permittivity, remnant polarization and pyrocurrent measurements, along with the scanning electron microscopy, prove the high density of the ceramics.

0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 Phosphate Composites: Dielectric and Ferroelectric Properties

“…The rounded shape of the P-E loops demonstrates the dilution of ferroelectric properties. Such shape of the P-E loop is not typical for the PMN-PT conventional ceramics [46]; however, it was previously reported for the PMN-PT-based composites [16]. Similarly, the difference might be attributed to the composite nature of the samples.…”

“…The effective media approach links the porosity of ceramics and ε [45]. This makes dielectric permittivity a sensitive tool to verify density measurements [46]. Similar to the density, ε demonstrates a plateau for samples pressed at 680-904 MPa.…”

Free‐standing 0.9Na0.5Bi0.5TiO3‐0.1Sr0.7Bi0.2TiO3 thick films produced by water‐based tape‐casting method

“…Although tape-casting is well known, particularly for production of Pb(Zr,Ti)O 3 thick films, 21,22 the available information about use of this method with such a small number of organic raw materials is very limited. 14 At the same time, this is of great interest due to the possibility to reduce the use of hazardous components in the production of ferroelectric thick films in such a way heading towards more eco-friendly approach. This aspect resonates with the choice of the research objectlead-free ferroelectrics.…”

“…Before sintering, green tapes can be separated from the substrate, allowing to get free‐standing films. Separation can be performed by different methods—etching and burning of a sacrificial layer, peeling‐off, and rapid temperature change 11,12,14 . Sintering of free‐standing thick films allows avoiding serious drawbacks, which inhere sintering of films on substrates 9,13 : ‐Limited possibilities of shrinkage in lateral direction are responsible for significant residual porosity of the film. ‐Mismatch of thermal expansion between the film and the substrate leads to cracks and delamination. ‐Possible chemical reaction between the film and the substrate compositions has to be taken into account. …”

“…In the present research, 0.9NBT‐0.1Sr 0.7 Bi 0.2 TiO 3 (0.9NBT‐0.1SBT) free‐standing thick films were produced by water‐based tape‐casting method using only two organic chemicals. Although tape‐casting is well known, particularly for production of Pb(Zr,Ti)O 3 thick films, 21,22 the available information about use of this method with such a small number of organic raw materials is very limited 14 . At the same time, this is of great interest due to the possibility to reduce the use of hazardous components in the production of ferroelectric thick films in such a way heading towards more eco‐friendly approach.…”