Lattice structure analysis and optimised microwave dielectric properties of LiAl1-x(Zn0.5Si0.5)xO2 solid solutions.

Abstract Low-permittivity LiAl 1- x (Zn 0.5 Si 0.5) x O 2 microwave dielectric ceramics were prepared by the solid-state reaction method. Single-phase LiAlO 2 solid solutions with a tetragonal structure were achieved at x ≤ 0.12. Partial substitution of [Zn 0.5 Si 0.5 ]3+ for Al3+ could improve the microstructure and prevent from absorbing moisture of pure LiAlO 2 ceramics, which slightly increases their relative permittivity (ε r). The quality factor (Q × f) and temperature coefficient of resonant frequency (τ f) were closely related to the crystallinity and cation disorder of the B-site characterized by the full width at half-maximum of B 1 (1) –mode assigned to Li–O–Al stretching. The optimum microwave dielectric properties (ε r = 6.12, Q × f = 56986 GHz and τ f = -122 ppm/°C) were obtained in the sample with x = 0.02 sintered at 1300 °C. [ABSTRACT FROM AUTHOR]