Improved high Q value of CaTiO3-Ca(Mg1/3Nb2/3)O-3 solid solution with nearzero temperature coefficient of resonant frequency

The crystal structures and the microwave dielectric properties of (1-x)CaTi O3-xCa(Mg1/3Nb2/3)O-3 perovskite ceramic system have been investigated, (1- x)CaTiO3-xCa(Mg1/3Nb2/3)O-3 solid solution exhibited orthorhombic crystal s tructures for all compositions. With x = 0.66, a new microwave dielectric c eramic material 0.34CaTiO(3)-0.66Ca(Mg1/3Nb2/3)O-3 applicable to microwave devices is suggested and possesses the dielectric properties of a dielectri c constant epsilon (r) similar to 48, a QXf values similar to 32,500 (at 6. 7 GHz) and a tau (f) value similar to -2 ppm/degreesC at 1450 degreesC for 3 h. Further improvement of the QXf value can be achieved by extending the sintering time to 6 h, It reveals a higher QXf value of 34,000 (at 6.7 GHz) without degrading other microwave dielectric properties of 0.34CaTiO(3)-0. 66Ca(Mg1/3Nb2/3)O-3 ceramics. (C) 2001 Elsevier Science Ltd. All rights res erved.