Crystal structure and microwave dielectric properties of CaTiO3-(Li1/2Nd1/2) TiO3-(Ln(1/3)Nd(1/3))TiO3 (Ln = La, Dy) ceramics

Crystal structure and microwave dielectric properties of a xCaTiO(3)-y(Li1/ 2Nd1/2)TiO3-z(Ln(1/3)Nd(1/3))TiO3 (Ln = La, Dy) ternary system were studied . Crystal structures were refilled by the Rietveld method using X-ray and n eutron diffraction data. (Li1/2Nd1/2)TiO3 and 0.2CaTiO(3)-0.8(La1/3Nd1/3)Ti O3 ceramics showed the most reliable R-values with a tetragonal structure w ith a space group P-4b2 and lattice constants of a = b approximate to 5.4 A ngstrom, and c approximate to 7.6 Angstrom. The A-site cations were ordered along the c-axis, When x greater than or equal to 0.3, the crystal structu re changed to an orthorhombic CaTiO3 type. The xCaTiO(3)-y(Li1/2Nd1/2)TiO3- z(La1/3Nd1/3)TiO3, system showed microwave dielectric properties of epsilon (r) = 133. Q.f = 1,450 GHz and tau(f) = -17 ppm/degrees C at a composition of x = 0.2, y = 0.68, z = 0.12. In xCaTiO(3)-y (Li1/2Nd1/2)TiO3-z(Dy1/3Nd1/ 3)TiO3, dielectric properties of epsilon(r) = 97.61 Q.f = 5, 150 GHz and ta u(f) = +0.4 ppm/degrees C were obtained at x = 0.30, y = 0.40, z = 0.30. Th e effect of each ternary system component on the dielectric properties is d iscussed.