The relationship between the bond ionicity, lattice energy, bond energy and microwave dielectric properties of LaNbO_4 ceramics

摘要

LaNbO~(4)ceramics with single monoclinic fergusonite structure were prepared by the conventional solid-state reaction method at the sintering temperature range of 1275–1375 °C. The correlations of bond ionicity, lattice energy, bond energy and the microwave dielectric properties were investigated. The bond ionicity, lattice energy, and bond energy were calculated based on the complex bond theory to analyze the variation trend of dielectric constant ( ε ~( r )), the Q  ×  f ~(0)value and the temperature coefficient of resonant frequency ( τ ~( f )), respectively. LaNbO~(4)ceramics sintered at 1350 °C for 4 h possessed excellent microwave dielectric properties: ε ~( r ) = 21, Q  ×  f ~(0) = 55600 GHz and τ ~( f ) = 8 ppm/°C.