Sintering process, phase composition, and microwave dielectric properties of NaLn(WO4)2(ln = La, Nd, Sm) ceramics prepared by reaction sintering method

Novel ultra-low loss NaLn(WO 4 ) 2 (Ln = La (NLW), Nd (NNW), Sm (NSW)) (NLnW) microwave dielectric ceramics were prepared by a reaction sintering method. The sintering process of the samples was investigated by TG-DSC. XRD refinement and Raman spectra results ascertained that the NLnW ceramics have scheelite structure with space group of I 4 1 /a . The microwave dielectric properties of NLnW ceramics and the relationship between the structure and performances were studied. The relationship between lattice vibration and Qf were analyzed by Raman spectroscopy. Especially, the NSW ceramics sintered at 1100 ℃ for 4 h show outstanding microwave dielectric properties of ε r = 10.07, Qf = 73,734 GHz (at 12.21 GHz), τ f = -42.6 ppm/°C, which providing a promising application in fifth generation communications.