Stable high thermal conductivities in BaTiO3 ceramic composites utilizing core-shell Ag@BaTiO3 particles

Ceramic/metal composites have drawn much attention in heat dissipations due to excellent performances, however, issues rise with the uncontrollable architecture and unstable properties resulting from metal-particle fusions at the high-temperature sintering. This study reports a BaTiO3 (BT) composite at a high Ag loading of 60 vol% with a stable composite architecture achieved by utilizing core-shell Ag@BT particles. Conformal-coated Ag@BT particles are prepared by simultaneous hydrolysis. The BT shell is vital in keeping Ag particles separately distributed and the shape well-retained in the BT matrix before and after the sintering to exhibit controllable structures. A high thermal conductivity of 84 W/mK is obtained in the composite at 25 degrees C, 35-fold enhanced compared with that of the BT ceramic of 2.4 W/mK. Low thermal barrier resistances as well as the nonpercolative behavior attributing to high thermal conductivities are owing to the unique composite architecture. The com-posite exhibits small fractures at Ag-BT interfaces while no macro fractures across the material are observed after the thermal cycling test. This study presents a BT/Ag@BT composite for various heat dissipation applications.

Automated summary

This study introduces a high Ag loading (60%) BaTiO3 (BT) composite with a stable structure achieved using core-shell Ag@BT particles. The composite exhibits a high thermal conductivity of 84 W/mK at 25 degrees C, 35 times higher than that of BT ceramic. The unique composite architecture results in low thermal barrier resistances and nonpercolative behavior, making it suitable for various heat dissipation applications.