Property control of microwave dielectric materials using self-flux compositions

In order to improve the sinterability and controllability of dielectric properties, we focused on self-flux composition. In the case of Ba(Mg1/3Nb2/3)O3, we selected Ba(1 − β)NbβOδ as self-flux system and investigated correlations between Q-factor and the β value. Interestingly, high Q-value was obtained only at the β = 0.45. Moreover, the dielectric constant (ɛr) and temperature coefficient of resonant frequency (τf) change linearly with the quantity of Ba0.55Nb 0.45Oδ by keeping up high Q-value. As a result, it was indicated that the dielectric properties could be controlled by the assumption of stoichiometric composition and the liquid phase consisted of “self-flux”. In a similar way of thinking, it seems that this concept of property designing will be applied to the complex-perovskite-type materials.