Microwave dielectric properties in the (1−x)(Na1/2La1/2)TiO3−x(Li1/2Sm1/2)TiO3 ceramic system

Abstract

Abstract Microwave dielectric properties have been investigated in the ceramic system (1− x )(Na 1/2 La 1/2 )TiO 3 − x (Li 1/2 Sm 1/2 )TiO 3 . In this system, (Na 1/2 La 1/2 )TiO 3 (NLT) exhibits relative permittivity ( e r) of 122, dielectric Q value ( Q ) of 3260 and a positive temperature coefficient of resonant frequency ( τ r ) of 480 ppm/°C at 3 GHz. On the other hand, (Li 1/2 Sm 1/2 )TiO 3 (LST) shows e r =52, Q =760 and τ f =−260 ppm/°C at 3 GHz. Therefore, an appropriate mixing of these two components yields material with both high permittivity and temperature-stable resonant frequency. From X-ray diffraction analyses, it was found that the ceramics are single phase perovskites. We have found that ceramics at the composition x =0.7 in this system (sintered at 1300 °C) have high e r of 117, Qf products of 2281 and temperature coefficient of resonant frequency τ f =−l9 ppm/°C at 3 GHz.