where 1and 2 are the relative permi

where 1and 2 are the relative permittivities of the ceramic and polymer, V1 and V2 are therespective volume fractions. Based on the logarithmic mixing law, the relative permittivity and dielectric loss of the obtained BaTiO3-PTFE composite (V1 = 0.95, V2 = 0.05) are estimated to be 1040 and 6.7%, respectively, which is inconsistent with those of obtained results (ɛ’ = 790, tanδ = 1.4 %). The differences between the two relative permittivities may be due to the previously discussed grain size effect in BaTiO3 ceramics. Further investigation will be necessary to thoroughly investigate this assumption. The 0.95BaTiO3-0.05PTFE composite displays a resistivity of approximately 1012 Ω cm, which is four orders of magnitude higher than that of cold sintered BaTiO3 (~ 108 Ω cm), as shown in Fig. 5(b). Given that the conventionally sintered undoped-BaTiO3 is an insulator with its resistivity between 109 and 1012 Ω cm at room temperature [44–46], the resistivity of cold sintered BaTiO3 is relatively low, probably due to the presence of residual fluxes and more defects at grain boundaries, consequence of the fast dissolution-precipitation kinetics during densification. Nevertheless, the cold sintered BaTiO3-PTFE composite shows a resistivity greater than or equal to the one of conventional undoped BaTiO3, as a result of the grain boundary engineering with PTFE. In the MLCC manufacturing, both high performance and high reliability have been achieved by finding effective additives[47–49]. Similarly, as demonstrated in this study, unprecedented additives, such as polymers, may be effective, as they can now be used to fabricate novel ferroelectric materials. Additional effects of the grain boundary engineering of BaTiO3 with polymers on the various properties, such as the breakdown strength, mobility of oxygen vacancies, as well as reliability tests are currently under investigation in our laboratory, but is beyond the scope of this paper, which is focused on the basic process, microstructure, properties and introduction of this new dielectric nanocomposite.