Microstructural Characteristics of Ba(Mg_1/3Ta_2/3)O₃ Ceramics and Its Related Microwave Dielectric Properties

Abstract

Microstructural characteristics such as second phases, defect types and order structure were investigated in Ba(Mg 1/3 Ta 2/3 )O 3 [BMT] ceramics using X-ray powder diffraction, scanning electron microscopy, wavelength-dispersive spectroscopy, and transmission electron microscopy. Two types of second phases having higher and lower Ba/Ta ratio compared to stoichiometric BMT, maybe exist in calcined powder of BMT. While one of them was consumed during sintering for 2 h, the other was remained after sintering. These results were discussed in terms of probable defect types in matrix of BMT. The presence and change of specific defect types can be correlated with the contribution of specific defect types to sintering behavior. Theoretical intensity of (100) superlattice reflection and saturated order parameter was also discussed. The microwave dielectric properties of sintered samples was discussed in terms of the presence of second phase and thus related defects types.