Microwave dielectric properties of (Zn1-xMgx)Nb2O6 ceramics

Dielectric ceramics comprised of (Zn1-xMgx)Nb2O6 (x=0-1) with prom using microwave properties were prepared by solid ceramic route. (Zn1-xMgx)Nb2O6 solid solutions exhibited columbite crystal structure for all compositions. The dielectric properties in this system exhibited a significant dependence on the sintering condition and composition of ceramics. The dielectric constant of (Zn1-xMgx)Nb2O6 ceramics increased with increasing relative densities for each x value. On the other hand, the dielectric constant of (Zn1-xMgx)Nb2O6 ceramics decreased from 23.66 to 19.7 as x value ranged from 0 to 1.0. The quality factors ( Q x f) of (Zn1-xMgx)Nb2O6 ceramics increased with increasing sintering temperature, after reached the maximum values, then decreased. The highest Q x f values of sintered ceramics changed nonlinearly and ranged from 81,220 to 33,112 GHz. The tau(f) showed a relative low value compared with those of ZnNb2O6 and MgNb2O6 and ranged from - 29.46 to - 70.56 ppm/degreesC. The tau(f) was improved at x = 0.5 and was - 29.46 ppm/degreesC. (C) 2003 Elsevier Science B.V All rights reserved.