Novel series of MLa2WO7(M = Sr, Ba) microwave dielectric ceramic systems with monoclinic structures

Novel series of MLa2WO7(M = Sr, Ba) ceramics were prepared via a traditional solid-state reaction method. The sintering characteristic, crystal structures, micromorphology and microwave dielectric performances of systems were systematically investigated. X-ray diffraction (XRD) and Rietveld refinement display that both SrLa2WO7(SLW) and BaLa2WO7(BLW) ceramics are monoclinic structure with Fdd (No. 14) space group. SLW and BLW ceramics have high relative density (more than 94%). The SLW ceramics sintered at 1400 degrees C exhibited good microwave dielectric performances with epsilon(r) = 23.2, Q x f = 29,720 GHz, tau(f) = - 127 ppm/degrees C and the BLW ceramics sintered at 1300 degrees C had excellent properties of epsilon(r) = 25.3, Q x f = 36,473 GHz, tau(f) = - 108 ppm/degrees C. These results show that MLa2WO7(M = Sr, Ba) ceramics could be candidates for microwave devices.