Low-temperature sintering and microstructure of Mg4(Nb2-xVx)O9 microwave dielectric ceramic by V substitution for Nb

The effects of microstructure on the microwave dielectric properties of Mg4Nb2O9 (MN) were investigated and the possibility of low-temperature sintering of Mg-4(Nb2-xVx)O-9 (MNV) by V substitution for Nb was also discussed in this study. The quality factors (Q.f) of MN ranged from 10338 to 217390 GHz with increasing sintering temperatures up to 1300degreesC, resulting in the grain growth and densification of the samples. In the case of V substitution for Nb, it was found that the limit of the solid solution is lower than x = 0.125; the improvements in the sinterability and apparent density of MNV at x = 0.0625 were recognized at the sintering temperature of 1025degreesC. The dielectric constants (epsilon(r),) and the Q.f values of MNV at x = 0.0625 sintered at 1025degreesC were 11.6 and 160256 GHz, respectively. Thus, it was clarified that a small amount of V substitution for Nb is effective in reducing the sintering temperatures and improving the microwave dielectric properties of MNV.