Tungsten Bronze Ferroelectric ceramics & Applications

The tetragonal tungsten bronze (TB)-type Lead-based ceramic materials, which have a high potential for use in ferroelectric and piezoelectric devices were fabricated by a high temperature conventional solid-state mixed oxide ceramic process. The systematic study of the effect of certain rare-earth ions (Re3+ =Sm3+, Nd3+, and Gd3+) doped in the above system on structural and ferroelectric studies have been carried out. Scanning electron microscopy (SEM) studies in these materials revealed fine grains are spherical in shape and obtained the grain size in all the compositions ranging between 1.60-2.90 µm. The phase transition temperature (TC) obtained in all-ceramic compositions from dielectric studies are well in agreement. It is observed that the high values of piezoelectric charge coefficients in d31 and d33 in Re3+ doped lead barium niobate ceramics. The piezoelectric voltage coefficient (g31) and mechanical quality factor (Qm) increased with an increase of rare-earth ion concentration in all the PBN ceramic compositions.