The influence of covalency of b'—o bond and packing fraction on the dielectric permittivity of Ba(B'1/3, B''2/3)O3 system

Various Ba(B'1/3, B''2/3)O3 compounds, where B' and B'' are divalent and pentavalent ions, respectively, with ordered B' and B'' ions are widely used in microwave circuits as dielectric resonator materials. This paper identifies the parameters responsible for the variations in dielectric permittivity of compounds of this type having different B' and B'' ions. The dielectric permittivity variation is correlated with the electronegativity of B' ions and packing fraction of the structure. The idea of a dipole lattice along with the Lorentz local field correction are applied to explain the observed dielectric property variation. The reason for the larger dielectric permittivity value of niobates than that of tantalates is also explained.

Keywords:

• Dielectric permittivity
• complex perovskites
• dielectric resonators
• Lorentz local field
• dipole lattice
• packing fraction