Microwave Dielectric Properties of SrRE4Si3O13 (RE=La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Er, Tm, Yb, and Y) Ceramics
Abstract:The apatite type SrRE4Si3O13 (RE=La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Er, Tm, Yb, and Y) ceramics have been prepared by the conventional solid-state ceramic route. The phase purity and surface morphology of the sintered ceramics were studied using X-ray diffraction and scanning electron microscopy methods. These materials showed poor sinterability and was improved by the addition of a small weight percentage of zinc borosilicate glass. The microwave dielectric properties of these materials were studied for the first time. SrRE4Si3O13 ceramics have a low relative permittivity (r) in the range 9–16, a Q-factor (Qu×f) upto 26 000 GHz and a low temperature coefficient of resonant frequency (f). The SrLa4Si3O13 ceramics possessed a high Qu×f of nearly 26 000 GHz but with a high negative f of −46 ppm/°C. The f of SrLa4Si3O13 ceramics was tuned by the addition of suitable amount of TiO2.
Document Type: Research Article
Affiliations: Materials and Minerals Division, National Institute for Interdisciplinary Science and Technology, Thiruvananthapuram 695019, India
Publication date: 2009-12-01