Structure and Microwave Dielectric Properties of a New Niobate Ba_3Nd_2Ti_2Nb_2O_(15)HU Chang-zheng1,2,ZHU Wen-feng1,2,WU Bo-lin1,2,ZHANG Gui-ling1,2 (1.Key Lab of Nonferrous Materials and New Processing Technology,Ministry of Education,Guilin University of Technology,Guilin 541004,China;2.Guangxi Key Lab for Advanced Materials and New Preparation Technology,Guilin 541004,China)A new niobate Ba3Nd2Ti2Nb2O15 was synthesized by high temperature solid state reaction in the BaO-Nd2O3-TiO2-Nb2O5 system.The chemical compositions,crystal structure,microstructure,and microwave dielectric properties of the new compound were characterized.Ba3Nd2Ti2Nb2O15 crystallizes in trigonal system with space group P3-ml(164)and lattice constants a=5.653 2(1) ?,c=11.611 7(2) ?,V=321.377(6) ?3,Z=1.The Ba3Nd2Ti2Nb2O15 ceramic exhibits a high dielectric constant of 40.1,high quality factors(Q) 3 390(at 5.754 2 GHz),and low temperature variation of resonant frequency(τf) +12×10-6K-1.Ba3Nd2Ti2Nb2O15 might be a suitable candidate of high εr microwave dielectric ceramics.new niobate;perovskite-like structure;dielectric properties