Structure and microwave dielectric properties of CaSmAlO4-CaTiO3-Sm0.9Nd0.1AlO3 ceramics with medium to high permittivity

The CaSmAlO4-doped 0.84CaTiO(3)-0.16Sm(0.9)Nd(0.1)AlO(3) ceramics with permittivity around 62 were prepared using a conventional solid-state reaction method. The relationship between their structures and microwave dielectric properties was explored by X-ray diffraction, Raman spectroscopy and scanning electron microscopy. A suitable amount of CaSmAlO4 addition is beneficial for improving the Qxf value and tuning tau(f) concurrently. However, excess amount of CaSmAlO4 generated secondary phase and deteriorated the Qxf value. The 0.5 mol% CaSmAlO4-doped 0.84CaTiO(3)-0.16Sm(0.9)Nd(0.1)AlO(3) ceramics exhibited the best performance of epsilon(r) = 62.3, Qxf = 38400 GHz and tau(f)=+49.5 ppm/degrees C sintered at 1400 degrees C for 6 h. Although the temperature stability needs to be made better, the CaSmAlO4-doped 0.84CaTiO(3)-0.16Sm(0.9)Nd(0.1)AlO(3) ceramics pave the way to develop a promising candidate for 5G dielectric resonators with medium-high permittivity (60 < epsilon(r) < 70). (C) 2020 The Ceramic Society of Japan. All rights reserved.