A low-firing Ca5Ni4(VO4)(6) ceramic with tunable microwave dielectric properties and chemical compatibility with Ag

摘要

A Ca5Ni4(VO4)(6) low loss microwave dielectric ceramic with A site deficient garnet structure was prepared via the conventional solid state reaction method. Ca5Ni4(VO4)(6) sintered at 980 degrees C for 4 h to a relative density of 96.2% exhibits favorable microwave dielectric properties such as a permittivity of 10.9, a Q x f value of 96,500 GHz, and a tau(f) value of -63.6 ppm/degrees C. Its large negative tau(f) could be compensated by forming a solid solution with LiCa2Mg2V3O12, that led to improved properties with a near-zero tau(f) = -3.7 ppm/degrees C, epsilon(r) = 10.2, Q x f = 59,300 GHz for 0.8Ca(5)Ni(4)(VO4)(6)-0.2LiCa(2)Mg(2)V(3)O(12) after sintering at 955 degrees C for 4 h. Further on, 0.8Ca(5)Ni(4)(VO4)(6)-0.2LiCa(2)Mg(2)V(3)O(12) proved to be chemically compatible with Ag electrodes, so it might be a possible candidate for LTCC applications. (C) 2016 Elsevier Ltd and Techna Group S.r.l. All rights reserved.