Microwave dielectric properties of (Li/sub 1/2/Nd/sub 1/2/)TiO/sub 3/-(Na/sub 1/2/Ln/sub 1/2/)TiO/sub 3/ (Ln=La,Nd,Sm) ceramic system

We have investigated the microwave dielectric properties of the (1-x)(Li/sub 1/2/Nd/sub 1/2/)TiO/sub 3/-x(Na/sub 1/2/Ln/sub 1/2/)TiO/sub 3/ (Ln=La,Nd,Sm), both of which have a perovskite structure. The dielectric constant /spl epsiv//sub r/ shows nonlinear behaviour and takes a maximum value at around x=0.4 for every Ln. However, the temperature coefficient /spl tau/f of resonant frequency changes from negative to positive as a function of x. In the case of Ln=Sm, excellent dielectric properties of /spl epsiv//sub r/=115, Q/spl middot/f=3800 GHz and /spl tau/f=15 ppm/C at around x=0.3.