  A new lead-free (1-x)Li0.12Na0.88NbO3-xBaTiO3 (0 to x to 40) piezoelectric
ceramics have been prepared using conventional ceramics processing route.
Structural analysis revealed an existence of morphotropic phase boundary (MPB),
separating orthorhombic and tetragonal phases, between the BaTiO3 content, x =
10-12.5. A partial phase diagram has been established based on
temperature-dependent permittivity data for this new system and a nearly
vertical temperature-independent MPB is observed. An improvement in electrical
properties near MPB (e.g., for x = 12.5; {\epsilon}r = 10489 at Tm, d33 = 30
pC/N, kp = 12.0 %, Qm = 162, Pr = 11.2 {\mu}C/cm2, Ec = 19.2 kV/cm, d*33 = 269
pm/V) is observed and is attributed to the ease of polarization rotation due to
coexistence of orthorhombic and tetragonal phases. The results show that these
materials could be suitable for piezoelectric vibrators and ultrasonic
transducers applications. The sample with x = 25, also shows high dielectric
permittivity, {\epsilon}r = 3060, and low dielectric loss, tan{\delta} = 0.033
which could be suitable for capacitor (X7R/Z5U) applications.
