Preparation of textured K2BiNb5O15 ceramics with rod-like templates by the screen-printing technique

This work focuses on the fabrication of textured ceramics with rod-like templates using screen-printing technique. Rod-like K2BiNb5O15 (KBIN) crystals with an aspect ratio of 10:1 were synthesized by the reaction of K2CO3, Bi2O3 and Nb2O5 in molten KCl flux at 1100 °C for 2 h. The KBIN templates were mixed with equiaxed powder of the same composition and oriented through the screen-printing reactive templated grain growth (SP-RTGG) technique. By printing onto a flexible polymer substrate and repeating the process of printing and drying, thick films with a thickness of several hundred micrometers were produced, then subsequently removed from the substrate, stacked layer by layer together and pressed into pieces. Textured KBIN ceramics were successfully obtained by this method. SEM and XRD were performed to study the grain growth and orientation degree. The textured K2BiNb5O15 ceramics showed an orientation degree (Lotgering factor) of 42% along 〈0 0 1〉 direction. The analysis of the dielectric properties of the textured K2BiNb5O15 ceramics revealed obvious anisotropies.

► The high-purity and rod-like KBIN templates with an aspect ratio of 10:1 have been synthesized via molten salt synthesis.
► Textured K2BiNb5O15 ceramics with a Lotgering factor of 42% along <001> direction were fabricated by the screen-printing template grain growth technique.
► The screen-printing technique has been successfully applied into texturing ceramics with rod-like templates.