Lowering Dielectric Loss and AC Conductivity of Polymer/HfC Composite Dielectric Films via Insulating Montmorillonite Barrier

Present work aimed at studying the effect of montmorillonite (MMT) on dielectric and conductive properties of composites based on polymer/hafnium carbide (HfC) mother composite system. Polymer/HfC/MMT composite films based on double-filler modification strategy were prepared by solution cast. To obtain control group, binary polymer/HfC composite films were prepared. MMT ceramic had excellent insulation property, which could suppress interface leakage current and thus reduce dielectric loss of composites. Compared with binary system, ternary system could show better overall electric features including mildly reduced permittivity, obviously reduced dielectric loss and conductivity. Optimized ternary composite bearing 3 wt% HfC and 3 wt% MMT exhibited a high permittivity of 34, low dielectric loss of 0.33 and low conductivity of 5.5 × 10−7 S m−1 at 100 Hz. This research might enable the fabrication of advanced composite dielectrics.