Li-containing ceramics with the TWB structure as new disordered ferroelectric materials

Temperature-frequency dependences of dielectric permittivity for Li-containing ceramics of solid solutions Ba/sub x/Pb/sub 4-x/Li/sub 2/Nb/sub 10/O/sub 30/ with the tetragonal wolfram bronze (TWB) structure have been studied. The presence of ferroelectric-paraelectric phase transition and deep low-frequency dispersion of the dielectric permittivity have been established for all studied compounds. Possible mechanisms responsible for dielectric dispersion and their connection with disordered arrangement of Li cations have been discussed.