Crystal structure and microwave dielectric properties of M(Nb_xTa_1−x)₂O₆ solid solution (M = Mg or Zn)

The microwave dielectric characteristics and crystal structure of the Zn(Nb_xTa_1−x)₂O₆ and Mg(Nb_xTa_1−x)₂O₆ systems have been investigated. It was found that both systems exhibited a morphotropic phase transition. Based on the results it was suggested that permittivity and temperature coefficient of resonant frequency depend more on crystal structure rather than on chemical composition. It was also suggested that a two-phase mixture is better than a solid solution for achieving both high quality factor and good temperature stability.