Tuning the microwave dielectric properties of La_(0.97)Sm_(0.03)(Mg_(0.5)Sn_(0.5))O_3 by adding Ca_(0.8)Sm_(0.4/3)TiO_3

摘要

The influence of sintering temperature on the microwave dielectric properties and microstructure of the (1 - y)La_(0.97)Sm_(0.03)(Mg_(0.5)Sn_(0.5))O_3-yCa_(0.8)Sm_(0.4/3)TiO_3 ceramic system were investigated with a view to their application in microwave devices. The (1 - y)La_(0.97)Sm_(0.03)(Mg_(0.5)Sn_(0.5))O_3-yCa_(0.8)Sm_(0.4/3)TiO_3 ceramic systems were prepared using the conventional solid-state method. The X-ray diffraction (XRD) patterns of the (1 - y)La_(0.97)Sm_(0.03)(Mg_(0.5)Sn_(0.5))O_3-yCa_(0.8)Sm_(0.4/3)TiO_3 ceramic system did not significantly vary with sintering temperature. The XRD patterns of the (1 - y) La_(0.97)Sm_(0.03)(Mg_(0.5)Sn_(0.5))O_3-yCa_(0.8)Sm_(0.4/3)TiO_3 ceramic system shifted to higher angle as y increased. A dielectric constant of 37.5, a quality factor (Q × f) of 40,300 GHz, and a temperature coefficient of resonant frequency of 2.4 ppm/℃ were obtained when the 0.425La_(0.97)Sm_(0.03)(Mg_(0.5)Sn_(0.5))O_3-0.575Ca_(0.8)Sm_(0.4/3)TiO_3 ceramic system was sintered at 1,600 ℃ for 4 h.