Barium Neodymium Titanium Borate Glass-Based High k Dielectrics

摘要

A nonconventional high k glass based on BaO-Nd_2O_3·-TiO_2·B_2O_3, which is combined with typical fillers of Al_2O_3 and BaTiO_3, has been investigated for the purpose of generating potential k (dielectric constant) ～20 and A ～ 40 dielectric materials as a result of densification at 850℃. Crystallization, den-sification, and dielectric properties depended strongly on the type and content of the fillers. Glass itself was crystallized mainly with BaTi(BO_3)_2. The Al_2O_3 filler did not seem to be directly involved in the crystallization process as only non Al-containing crystalline phases, such as NdBO_3, Nd_2Ti_4O_(11), and BaNd_2Ti_5O_(14), were observed. On the contrary, the Ba-TiO, filler resulted in the crystallization of two phases, BaTi (BO_3)_2 and BaNd_2Ti_5O_(14). As an example of a promising dielectric candidate, a composite sample consisting of the glass and 30 wt% Al_2O_3 exhibited k ～ 22 and tan δ ～ 0.009 with nearly full densification at 850℃.