Dielectric and piezoelectric properties of (1-x)(K0.474Na0.474Li0.052)(Nb0.948Sb0.052)O3-xBaMO3 (M = Ti or Zr) ceramics

ABSTRACTThe effects of Ba and M (M = Ti or Zr) substitutions for K, Na, Li, Nb and Sb on the ferroelectric and piezoelectric properties of (1-x)(K0.474Na0.474Li0.052)(Nb0.948Sb0.052)O3 (KNLNS)-xBaMO3 ceramics were investigated. X-ray powder diffraction profiles showed the coexistence of rhombohedral-orthorhombic-tetragonal phases, representing a morphotropic phase boundary (MPB), in both (1-x)KNLNS-xBaTiO3 (BT) and (1-x)KNLNS-xBaZrO3 (BZ) ceramics. DSC measurement of (1-x)KNLNS-xBZ ceramics indicated that the Ba and Zr substitutions for A- and B-sites in KNLNS led to the further increase in the dielectric constant in comparison with that of (1-x)KNLNS-xBT ceramics. Moreover, the rhombohedral-orthorhombic phase transition temperature was decreased to room temperature by Ba and Zr substitutions; as a result, a d33 value of 337 pC/N was obtained at 0.94KNLNS-0.06BZ (x = 0.06) ceramic.