Barium Neodymium Titanium Borate Glass‐Based High k Dielectrics
A nonconventional high k glass based on BaO·Nd2O3·TiO2·B2O3,
which is combined with typical fillers of Al2O3 and BaTiO3, has been investigated for the purpose of generating potential k (dielectric constant)
~20 and k ~ 40 dielectric materials as a result of densification at 850°C. Crystallization, densification, and dielectric properties depended strongly on the type and content of the fillers. Glass itself was crystallized mainly with BaTi(BO3)2.
The Al2O3 filler did not seem to be directly involved in the crystallization process as only non Al‐containing crystalline phases, such as NdBO3,
Nd2Ti4O11, and BaNd2Ti5O14, were observed. On the contrary,
the BaTiO3 filler resulted in the crystallization of two phases, BaTi(BO3)2 and BaNd2Ti5O14.
As an example of a promising dielectric candidate, a composite sample consisting of the glass and 30 wt% Al2O3 exhibited k ~ 22 and tan δ ~ 0.009 with nearly full densification at 850°C.